where was the first abercrombie and fitch store

The company was originally established as Abercrombie Co. by David Abercrombie on June 4, 1892, in a small waterfront shop at 36 South Street in downtown Manhattan, New York. Wealthy New York businessman Ezra Fitch became one of the store's regular customers. In 1900, Fitch bought a major share in the growing Abercrombie Company and thus joined as co-founder. Abercrombie Co. later moved into larger quarters at 314 Broadway, and Fitch began to implement experimental ideas to renovate the store. In 1904, Fitch's surname was added to Abercrombie's and so the official name became Abercrombie & Fitch Co.[citation needed]

History of Abercrombie & Fitch

The history of Abercrombie & Fitch began in the nineteenth century and extends into the twenty-first century. Key figures who changed and influenced the course of Abercrombie & Fitch's history include co-founders David T. Abercrombie and Ezra Fitch, Limited Brands and Michael Jeffries, the former Chairman and CEO.[1]

David Abercrombie founded A&F in 1892 as an upscale sporting goods store. Forming a partnership with Ezra Fitch, the company continued to expand in the new 20th century. After Abercrombie left the company, Fitch became sole owner and ushered in the "Fitch Years" of continued success. Shortly after his retirement, the company continued to develop under a succession of other leaders until its financial fall and closing in 1977. Limited Brands purchased the ailing brand in 1988 and brought in Mike Jeffries, who revolutionized the image of Abercrombie & Fitch to become an upscale youthful fashion retailer. Today, the company is a multibillion-dollar entity continuing to experience economic expansion through the business continuance of three offshoot growing concepts and cautious international expansion into key luxury markets.

Prominent figures who patronized the company in its excursion goods days of the early 20th century include Teddy Roosevelt,[2] Amelia Earhart,[2][3] Greta Garbo,[2] Katharine Hepburn,[2] Clark Gable,[2] John Steinbeck,[4][5] John F. Kennedy,[5] Ernest Shackleton,[6] Cole Porter,[7] and Dwight Eisenhower.[5]

The partnership between Abercrombie and Fitch did not end happily. The two men, with different visions for the future of A&F, quarreled frequently, although the company continued to prosper. Fitch wished to expand the company's appeal to the general public, while Abercrombie wanted to continue selling professional gear to professional outdoorsmen.[8] As a result of the disagreement, Abercrombie sold his share in the company to Fitch in 1907 and returned to manufacturing outdoor goods.[9] Fitch continued the business with other partners and directed the company as he pleased.

In 1909, Abercrombie & Fitch Co. mailed over 50,000 copies of its 456-page catalog worldwide (a staggering and costly amount of publication at that time, since each cost a dollar to produce).[10] The catalog featured outdoor clothing, camping gear, articles, and advice columns. The cost of the catalog nearly bankrupted the company, but the catalog proved to be a profitable marketing device. Within the store, the catalog was available to customers for free. By 1910, the company began selling women's clothing,[9] and became the first store in New York to supply clothing to women as well as men.[citation needed] In 1913, after moving into Reade Street, which was not a convenient shopping location for women, the store relocated to a more fashionable and easily accessible midtown address near Fifth Avenue at 55/57 West 36th Street, expanding its inventory to include sportswear. In 1917, the store moved again into a twelve-story building at the corner of Madison Avenue and East 45th Street.[11] The store occupied the entire available space (12 stories). Mr. Abercrombie was a farmer who thought clothes during the 19th century were boring. He became famous with his best friend Mr. Fitch. They then created Abercrombie and Fitch.

The Madison Avenue store included many different amenities. The basement housed a shooting range while on the mezzanine (main floor) paraphernalia for skiing, archery, free diving, and lawn games were sold. The second through fifth floors were reserved for clothing that was suitable for different climate or terrains. On the sixth floor were a picture gallery, a bookstore (focused on sporting themes), a watch repair facility and a golf school (fully equipped with a resident professional). The seventh floor included a gun room with hundreds of shotguns and rifles, decorated with stuffed game heads, as well as a kennel for dogs and cats.[11] The eighth floor contained fishing, camping, and boating equipment and included a desk for a fly- and bait-casting instructor who gave lessons at the pool, which was located on the roof. The fishing section alone was stocked with over 48,000 flies and over 18,000 fishing lures.[11]

Abercrombie & Fitch Co. became the first American store to import Mahjong.[12] Ezra Fitch imported the game after a female customer looked for the game that she had played in China. He went to China for the game and translated the instructions into English. Mahjong became a fast selling product, and Abercrombie & Fitch became the epicenter of the Mahjong craze.[10] The company sent emissaries to Chinese villages to buy as many Mahjong sets as possible and eventually sold over 12,000 sets.

In 1927, Abercrombie & Fitch outfitted Charles Lindbergh for his historic flight across the Atlantic Ocean.[13] It also attracted the business of other prominent figures.[14]

In 1928, Fitch retired from the company and sold to his brother-in-law, James S. Cobb.[9][10] Under Cobb, A&F acquired Von Lengerke & Detmold, a well-respected New York dealer of fine European-made sporting guns and fishing tackle, as well as that company's Chicago branch, Von Lengerke & Antoine. Cobb also acquired Griffin & Howe, another gunsmith company. Merchandise from both Von Lengerke & Detmold and Griffin & Howe was carried at A&F's Madison Avenue store.[10] By this time, A&F was also selling equipment for polo, golf, and tennis.[10] By 1929, sales of US $6.3 million were reported with net profits of US $548,000.[10]

During the Great Depression, the company's revenue decreased and it stopped paying dividends. Sales plunged to $2,598,925 in 1933. A&F recovered in the following years and resumed paying dividends in 1938.[10] During that year, guns accounted for 40% of sales at the Madison Avenue store.[10] Clothing, shoes, and furnishings accounted for 45%, while inventory was valued at about 40% of annual sales (reflecting A&F's readiness to meet customer demands).[10] Ten percent of the business was attributed to mail orders from the catalog.[10] Abercrombie & Fitch Co. continued to expand. As early as 1913, A&F had adopted the slogan, "The Greatest Sporting Goods Store in the World".[10]

A&F's record net profit was $682,894 in 1947.[10] The company opened a large branch in San Francisco in 1958. It soon added small winter-only shops open from November through May each season in Palm Beach and Sarasota, Florida and summer-only shops in Bay Head, New Jersey, and Southampton, New York.[10] to complement a shop in Hyannis, Massachusetts it had operated since the end of World War II. Guernsey succeeded Cobb as president.[10] He remarked, "The Abercrombie & Fitch type does not care about the cost; he wants the finest quality."[10] With so many locations now under the control of Abercrombie & Fitch, the Madison Avenue store remained the flagship store.[10] In the 1950s, the main floor of the flagship was remodeled to include heads of buffalo, caribou, moose, elk, and other big game, stuffed fish of spectacular size, and elephant's-foot wastebaskets.[10]

In 1960, net sales rose to $16.5 million, but net profit fell for the fourth straight year to $185,649.[10] By 1961, net sales dropped to $15.5 million, and net profit to $124,097. Guernsey's successor as president, John H. Ewing, paid little attention to the decline in sales.[10] In 1961, he told an interviewer of Business Week that Abercrombie & Fitch enjoyed a special niche "by sticking to our knitting; by not trying to be all things to all people."[10] A&F would open a year-round resort shop at The Broadmoor resort in Colorado Springs (1962) and its first suburban store at the Mall in Short Hills, New Jersey (1963). Under the leadership of Earle K. Angstadt, Jr., Abercrombie's continued to expand in upscale locations such as the Bal Harbour Shops near Miami Beach, Florida (1966), the Somerset Mall in Troy, Michigan, outside Detroit (1969) and in boutique-style shops in other department stores.[10]

In 1964, Abercrombie and Fitch achieved a notable early example of the "brand integration" form of product placement by providing the venue for part of the Rock Hudson / Paula Prentiss romantic comedy film Man's Favorite Sport?.

Abercrombie and Fitch held a warehouse sale in 1968 and early 1970 and presented offbeat newspaper advertisements that reflected a measure of desperation.[10] The company's revenue continued decline, with a loss of about $500,000 in its previous fiscal year. Noticing the effect that the ads and sale-days had upon the Abercrombie & Fitch customer base, the next president William Humphreys, a former Lord & Taylor executive, halted the measures.[10] He focused on improving A&F's inventory control and credit practices and cutting the company's expenses.;[10] changed the store design to present a different image, focused on expansion into the suburbs in 1972 with a location in Oak Brook, Illinois 1972 in hopes of recapturing customers who no longer patronized its store in downtown Chicago's Loop.[10] Noticing that the offbeat advertisements were bringing in customers that management considered "not of classic Abercrombie & Fitch material," A&F ceased its mis-directing ads and sale-days in October 1970.[10] Presentation within the flagship changed as well to provide a newer look. Expensive sailboats were moved from the main floor to an upper floor, a discount clothing section was introduced on the tenth floor, sportswear lines were expanded, and new buyers for woman's apparel were hired.[10] However, the changes did not improve sales and the company continued to decline financially under Humphreys and his successor Hal Haskell, who was a major stockholder of the company.[10] After losing $1 million in 1975, Abercrombie & Fitch Co. filed for chapter 11 bankruptcy in August 1976 and finally closed its doors in November 1977.[15]

Oshman's, a sporting goods retailer, acquired Abercrombie & Fitch Co. in 1978 for $1.5 million[16][17] ($5.2 million in 2013 dollars).[18] It opened an Abercrombie & Fitch store in 1979 in Beverly Hills, California, and another in Dallas, Texas, which was bigger and sported $40,000 USD elephant guns and an "Abercrombie Runabout sports convertible" worth $20,775 USD.[10] Stores continued to open in South Street Seaport and Trump Tower and catered towards contemporary interests of golf, exercise, and tennis.[10] Clothing collections for men and women carried business and casual dress, and sportswear.[10] Forbes described the merchandise as "a hodgepodge of unrelated items" and that "sometimes it is better to bury the dead than to try reviving them." Abercrombie & Fitch continued to struggle as Oshman's struggled itself to develop a strong identity for the company.[11]

In 1988, Limited Brands acquired the ailing company for $47 million after having success in popularizing Express and Victoria's Secret.[19] Headquarters was moved to Columbus, Ohio, and all inventory was cleared out.[10] The new president of Abercrombie & Fitch, Sally Frame-Kasaks, placed a strong emphasis on apparel.[16] Michael S. Jeffries, a clothing executive, took over as president in 1992.[7][20] He popularized the brand to a teen apparel merchandiser from an ailing sports brand. He believed that focusing the A&F brand towards the American teen market would be financially beneficial as that sector of retail economy was said to be growing at a record rate at the time.[21]

The new Abercrombie & Fitch reopened shortly afterwords with a preppy outdoors theme reminiscent of the company's original roots.[21] Jeffries desired to have Bruce Weber, known for his sexual beefcake photography, as the photographer for the brand, but could not do so until the company gained financial success. The apparel consisted of woven shirts, denim, miniskirts, cargo shorts, wool sweaters, polo shirts, and t-shirts. Its prices were unprecedentedly high in the teen apparel industry.[21] Sales rose $85 million in 1992, $111 million in 1993, and to $165 million in 1994.[10][20] 49 stores were opened by 1994, and a 102 store count was aimed by the end of 1995.[10] In 1994, new records for merchandise margin rate and profitability were established by Abercrombie & Fitch for its parent, The Limited.[21] To maintain popularity and to keep up with teen trends, Jeffries hired executives to keep up on popular teenage clothing, music, and entertainment.[21]

By the mid-1990s, there were dozens of Abercrombie & Fitch stores in the United States.[22] On September 26, 1996, The Limited, Inc. took Abercrombie & Fitch public on the New York Stock Exchange with the ticker symbol "ANF" and with the per share offering as $16.[23] In late 1990s, the company began to opt building stores only averaging between 8,000 and 20,000 square feet (700 to 2,000 mÂ²) in high-volume retail centers around the country. It also launched the canoe store prototype of white facade and interior gray walls to accommodate the growth of its brand.

In 1997, Abercrombie & Fitch launched A&F Quarterly. The publication included photography, interviews and articles about sex, pop culture, and other teen interests.[21] In 1998, the company introduced its first subsidiary, abercrombie. The concept was designed as the Abercrombie & Fitch for a younger clientele between the ages on 7-14. In 1999 began a 3-year-long class action lawsuit in which Abercrombie & Fitch was one of several American retailers involved for its sweatshops in Saipan.[24] Revenue recorded for Abercrombie & Fitch at the end of fiscal 1998 was at $805.2 million USD. By 1998, Abercrombie & Fitch became an independent company, and Mike Jeffries assumed the position of Chairman and Chief Executive Officer.[7] As the brand regained its prominence, industry analysts began to speculate how long Abercrombie and Fitch would be able to retain its popularity.[21]

Analysts predicted that A&F would fall from popularity, but sales continued escalating after a provocative Christmas 1999 in which the A&F Quarterly issue of the season featured sexually explicit content that drew angry complaints.[21] In 1999, the A&F also launched "A&F TV", which featured young people engaged in sports and leisure activities. A&F TV was originally developed to run on cable television and on monitors in Abercrombie & Fitch stores. It was soon removed. Revenue for fiscal 1999 was at  $1.030 billion USD.

The overall approach of Abercrombie & Fitch, by the end of the decade, to its customers seemed to please male shoppers more than females, who shopped more frequently at competitor shops.[21] Throughout the 1990s, Abercrombie & Fitch Co. enjoyed sales of over $400/ft2 ($4300/m2). By December 1999, Abercrombie & Fitch operated a total of 212 stores nationwide.[25]

Entering into the 21st century, Abercrombie & Fitch was rated as the sixth most popular brand before Nintendo and Levi's by teenagers.[26] The company introduced its third brand, Hollister Co., in July 2000. The third concept was based on Southern California surf lifestyle, and was targeted towards high school students. After Hollister lowered the revenue of Abercrombie & Fitch, the company launched the Ezra Fitch collection, and began producing A&F clothing with higher grade materials, increasing the prices. In 2001, the company moved into a new 300-acre (1.2Â km2) home office in New Albany, Ohio. Headquarters were further expanded by 2003.[27] Also in 2003, the company released its last issue of A&F Quarterly after amounting complaints.

After successfully launching Hollister, the company introduced its fourth brand RUEHL No.925 for older consumers, 22 through 35, on September 24, 2004.[28] Revenue continued to escalate as sales are reported at $2.021 billion for 2004. In November 2005, the company opened doors to its first ever flagship store (located in Fifth Avenue). By this time, the company begins to uplift its image to near-luxury status after introducing the trademark Casual Luxury for promotion. Revenue reported for 2005 was $2.021 billion.[29]

Abercrombie & Fitch began its Canadian expansion in January 2006 when the company opened two A&F stores and three Hollister Co. stores in Toronto and Edmonton.[30] By fall 2006, a third Canadian Abercrombie & Fitch store opened in the Toronto Eaton Centre. Also in the year, the brand opened a west coast flagship in The Grove.[31] Revenue reported for 2006 is $3.318 billion, an increase of over $1.297 billion from 2005.

Beginning 2007, the canoe stores were revamped with dark louvers (see right image). On 22 March 2007, Abercrombie & Fitch opened its first European flagship in London at 7 Burlington Gardens in Savile Row.[32] The store generated a volume of $280,000 (around Â£140,000 GBP) in its first 6 hours of operation.[6][33] The flagship remains one of the most profitable A&F locations. Revenue reached record heights in 2007 with an overall sales of $3.749 billion.

On 21 January 2008, Abercrombie & Fitch introduced its fifth concept, the intimate apparel brand Gilly Hicks.[34] Inspired by "Down Under", it is officially labeled as the "Cheeky cousin of Abercrombie & Fitch." In April 2008, A&F relaunched A&F Quarterly for release in the UK flagship.[35][36] On August 31, 2008, the "bright and insightful" company director Allan A. Tuttle died.[37] By December 22, corporate announced that it had produced a new employment agreement with Mike Jeffries set to expire in 2014.[38] For the first time in its recent history, A&F suffered a financial decrease to $3.540 billion revenue for fiscal 2008. The blame was to the current economic recession, and also to the fact that the company refused to lower price points and offer sales citing brand image-protection that doing so would "cheapen" its near-luxury image.

As the late-2000s recession continued, A&F noticeably suffered financially for its refusal to lower prices or offer discounts. Early in January 2009, the company reported its worst drop in sales and shares.[39][40] By the end of the month, 50 employees lost their jobs and many positions were still unoccupied.[41] 170 more employees were dismissed in May.[42] A&F announced on 17 June 2009 the closure of its ailing Ruehl No.925 brand by January 2010.[43] By October, A&F launched its official Facebook page. Despite financial downturns, A&F opened its second European location, a flagship store, in Milan on October 29.[44] On its official Facebook page, A&F called it the biggest consumer reception for a flagship opening in A&F history: "like nothing the world has seen before". On December 15, another flagship store opened in Tokyo, Japan. Marking the first ever A&F location in Asia, the opening became the biggest retail event in history, was noted as a "spectacle of consumerism" by the Japanese, and made around JPÂ¥50 million (US$550,000) that day alone.[45][46][47]

In January 2010, A&F launched its A&F Cares feature highlighting its philanthropic efforts. Keeping to its commitment, the company shut down ruehl.com on January 22, and closed doors to all final Ruehl stores by the end of the month. Analysts began noting encouraging signs of financial progress, in March, for the company, citing A&F's successful international expansion and better inventory management.[48] Also around that time, a historical fishing line dryer, made by A&F in the early 1900s, was sold to an A&F model for $590 USD.[49][50] As a marketing move, A&F announced the relaunch of the A&F Quarterly on 17 July 2010 as a part of its "Screen Test" Back-to-School marketing campaign designed to attract more consumer attention and sales.[51] In August, CEO Mike Jeffries announced that Abercrombie & Fitch would close roughly 60 stores in 2010.[52] Later that month, CFO Jonathan Ramsden said another 50 stores could close in 2011.[52] Profits began to pick up by September 2010 to larger than predicted results (attributted to the result of the major "Screen Test" campaign and numerous sales held throughout the season).[53] By October, the company was stated as being well ahead its competitors (a first since the economic turndown).[54] The brand opened a flagship in Copenhagen and Fukuoka in November 2010, and another one in Paris by May 2011.

On February 15, 2012, A&F announced plans to close 180 more underperforming U.S. stores by 2015 while continuing to expand in Europe and Asia.[55]

In 2013, the company's trendy, upscale image took a hit when comments made by Jeffries in 2006 that disparaged customers with body types that do not resemble Abercrombie & Fitch models resurfaced. The resulting backlash launched a viral internet campaign called "Fitch the Homeless", which aimed to subvert and mock the company's carefully manicured image of "exclusionary" style by distributing used Abercrombie & Fitch clothes to homeless and needy persons.[56]


why the delay in queen elizabeth's coronation

The coronation of Elizabeth II took place on 2 June 1953 at Westminster Abbey, London.[1] Elizabeth ascended the throne at the age of 25 upon the death of her father, George VI, on 6 February 1952, being proclaimed queen by her privy and executive councils shortly afterwards. The coronation was held more than one year later because of the tradition of allowing an appropriate length of time to pass after a monarch dies before holding such festivals. It also gave the planning committees adequate time to make preparations for the ceremony. During the service, Elizabeth took an oath, was anointed with holy oil, invested with robes and regalia, and crowned Queen of the United Kingdom, Canada, Australia, New Zealand, South Africa, Pakistan, and Ceylon (now Sri Lanka).[2]

Coronation of Elizabeth II

Celebrations took place across the Commonwealth realms and a commemorative medal was issued. It was the first British coronation to be televised; television cameras had not been allowed inside the abbey during her father's coronation in 1937. Elizabeth's was the fourth and last British coronation of the 20th century. It was estimated to have cost £1.57 million (c. £38,680,000 in 2016).

The one-day ceremony took 14 months of preparation: the first meeting of the Coronation Commission was in April 1952,[3] under the chairmanship of the Queen's husband, Philip, Duke of Edinburgh.[4][5] Other committees were also formed, such as the Coronation Joint Committee and the Coronation Executive Committee,[6] both chaired by the Duke of Norfolk who,[7] by convention as Earl Marshal, had overall responsibility for the event. Many physical preparations and decorations along the route were the responsibility of David Eccles, Minister of Works. Eccles described his role and that of the Earl Marshal: "The Earl Marshal is the producer â€“ I am the stage manager..."[8]

The committees involved high commissioners from other Commonwealth realms, reflecting the international nature of the coronation; however, officials from other Commonwealth realms declined invitations to participate in the event because the governments of those countries considered the ceremony to be a religious rite unique to Britain. As Canadian Prime Minister Louis St. Laurent said at the time: "In my view the Coronation is the official enthronement of the Sovereign as Sovereign of the UK. We are happy to attend and witness the Coronation of the Sovereign of the UK but we are not direct participants in that function."[9] The Coronation Commission announced in June 1952 that the coronation would take place on 2 June 1953.[10]

Norman Hartnell was commissioned by the Queen to design the outfits for all members of the royal family, including Elizabeth's coronation gown. His design for the gown evolved through nine proposals, and the final version resulted from his own research and numerous meetings with the Queen: a white silk dress embroidered with floral emblems of the countries of the Commonwealth at the time: the Tudor rose of England, Scottish thistle, Welsh leek, shamrock for Northern Ireland, wattle of Australia, maple leaf of Canada, the New Zealand silver fern, South Africa's protea, two lotus flowers for India and Ceylon, and Pakistan's wheat, cotton and jute. Unknown to the Queen was a four-leaf clover embroidered on the dress's left-hand side, which her hand would touch throughout the day.[11][12]

Elizabeth rehearsed for the occasion with her maids of honour. A sheet was used in place of the velvet train, and a formation of chairs stood in for the carriage. She also wore the Imperial State Crown while going about her daily business – at her desk, during tea, and while reading a newspaper – so that she could become accustomed to its feel and weight.[11] Elizabeth took part in two full rehearsals at Westminster Abbey, on 22 and 29 May,[13] though some sources claim that she attended one or "several" rehearsals.[14][15] The Duchess of Norfolk usually stood in for the Queen at rehearsals.[citation needed]

Elizabeth's grandmother Queen Mary had died on 24 March 1953, having stated in her will that her death should not affect the planning of the coronation, and the event went ahead as scheduled.[10] It was estimated to cost £1.57 million (c. £38,680,000 in 2016[16]), which included stands along the procession route to accommodate 96,000 people, lavatories, street decorations, outfits, car hire, repairs to the state coach, and alterations to the Queen's regalia.[17]

The Coronation ceremony of Elizabeth II followed a similar pattern to the coronations of the kings and queens before her, being held in Westminster Abbey, and involving the peerage and clergy. However, for the new Queen, several parts of the ceremony were markedly different. The coronation of the Queen was the first ever to be televised (although the BBC Television Service had covered part of the procession from Westminster Abbey after her father's coronation in 1937[18]), and was also the world's first major international event to be broadcast on television. There had been considerable debate within the British Cabinet on the subject, with Prime Minister Winston Churchill against the idea; but, Elizabeth refused his advice on this matter and insisted the event take place before television cameras,[19] as well as those filming with experimental 3D technology.[n 1][20] The event was also filmed in colour, separately from the BBC's black and white television broadcast.[21] Millions across Britain watched the coronation live, while, to make sure Canadians could see it on the same day, RAF Canberras flew BBC film recordings of the ceremony across the Atlantic Ocean to be broadcast by the Canadian Broadcasting Corporation,[22] the first non-stop flights between the United Kingdom and the Canadian mainland. At Goose Bay, Labrador, the first batch of film was transferred to a Royal Canadian Air Force CF-100 jet fighter for the further trip to Montreal. In all, three such flights were made as the coronation proceeded, with the first and second Canberras taking the second and third batches of film to Montreal respectively.[23]  US networks NBC and CBS made similar arrangements to have films flown in relays back to the United States for same-day broadcast, but used slower propeller-driven aircraft. The struggling ABC network arranged to re-transmit the CBC broadcast taking the on-the-air signal from the CBC's Toronto station and feeding the network from ABC's affiliate in Buffalo, New York, as a result, beat the other two networks to air by more than one and a half hours (at considerably lower cost). Film was also dispatched to Australia aboard a Qantas airliner, which arrived in Sydney in a record time of 53 hours 28 minutes.[24] The worldwide television audience for the coronation was estimated to be 277 million.[25]

Along a route lined with sailors, soldiers, and airmen and women from across the British Empire and Commonwealth,[n 2][26] guests and officials passed in a procession before about three million spectators gathered in the streets of London, some having camped overnight in their spot to ensure a view of the monarch, and others having access to specially built stands and scaffolding along the route.[27] For those not present to witness the event, more than 200 microphones were stationed along the path and in Westminster Abbey, with 750 commentators broadcasting descriptions in 39 languages;[23] more than twenty million viewers around the world watched the coverage.[27]

The procession included foreign royalty and heads of state riding to Westminster Abbey in various carriages, so many that volunteers ranging from wealthy businessmen to rural landowners were required to supplement the insufficient ranks of regular footmen.[27] The first royal coach left Buckingham Palace and moved down the Mall, which was filled with flag-waving and cheering crowds. It was followed by the Irish State Coach carrying Queen Elizabeth the Queen Mother, who wore the circlet of her crown bearing the Koh-i-Noor diamond. Queen Elizabeth II proceeded through London from Buckingham Palace, through Trafalgar Square, and towards the abbey in the Gold State Coach. Attached to the shoulders of her dress, the Queen wore the Robe of State, a 6-yard (5.5 metre) long, hand woven silk velvet cloak lined with Canadian ermine that required the assistance of the Queen's maids of honour—Lady Jane Vane-Tempest-Stewart, Lady Anne Coke, Lady Moyra Hamilton, Lady Mary Baillie-Hamilton, Lady Jane Heathcote-Drummond-Willoughby, Lady Rosemary Spencer-Churchill and the Duchess of Devonshire[28]—to carry.[11]

The return procession followed a route that was 5 miles (8 kilometres) in length, passing through Whitehall, Trafalgar Square, Pall Mall, Hyde Park Corner, Marble Arch, Oxford Circus, and finally down the Mall to Buckingham Palace. 29,000 service personnel from Britain and across the Commonwealth marched in a procession that was two miles (3.2 kilometres) long and took 45 minutes to pass any given point. A further 15,800 lined the route.[29] The parade was led by Colonel Burrows of the War Office staff and four regimental bands. Then came the colonial contingents, then troops from the Commonwealth realms, followed by the Royal Air Force, the British Army, the Royal Navy, and finally the Household Brigade.[30] Behind the marching troops was a carriage procession led by the rulers of the British protectorates, including the

After being closed since the Queen's accession for coronation preparations, Westminster Abbey was opened at 6 am on Coronation Day to the approximately 8,000 guests invited from across the Commonwealth of Nations;[n 3][27][34] more prominent individuals, such as members of the Queen's family and foreign royalty, the peers of the United Kingdom, heads of state, Members of Parliament from the Queen's various legislatures,[35] and the like, arrived after 8:30 am. Tonga's Queen Sālote was a guest, and was noted for her cheery demeanour while riding in an open carriage through London in the rain.[36] General George Marshall, the United States Secretary of State who implemented the Marshall Plan, was appointed chairman of the US delegation to the coronation and attended the ceremony along with his wife, Katherine.[37]

Guests seated on stools were able to purchase their stools[clarification needed] following the ceremony, with the profits going towards the cost of the Coronation.[38]

Preceding the Queen into Westminster Abbey was St Edward's Crown, carried into the abbey by the Lord High Steward of England, then the Viscount Cunningham of Hyndhope, who was flanked by two other peers, while the Archbishops and Bishops Assistant of the Church of England, in their copes and mitres, waited outside the Great West Door for the arrival of the Queen. When the Queen arrived at about 11:00 am,[11][19] she found that the friction between her robes and the carpet caused her difficulty moving forward, and she said to the Archbishop of Canterbury, Geoffrey Fisher, "Get me started!"[19] Once going, the procession, which included the various High Commissioners of the Commonwealth carrying banners bearing the shields of the coats of arms of their respective nations,[39] moved inside the abbey, up the central aisle and through the choir to the stage, as the choirs sang "I was glad", an imperial setting of Psalm 122, vv. 1–3, 6, and 7 by Sir Hubert Parry.[40] As Elizabeth prayed at and then seated herself on the Chair of Estate to the south of the altar, the Bishops carried in the religious paraphernalia—the bible, paten and chalice—and the peers holding the coronation regalia handed them over to the Archbishop of Canterbury, who, in turn, passed them to the Dean of Westminster, Alan Campbell Don, to be placed on the altar.[41]

After the Queen moved to stand before King Edward's Chair (Coronation Chair), she turned, following as Fisher, along with the Lord High Chancellor of Great Britain (the Viscount Simonds), Lord Great Chamberlain of England (the Marquess of Cholmondeley), Lord High Constable of England (the Viscount Alanbrooke) and Earl Marshal of the United Kingdom (the Duke of Norfolk), all led by the Garter Principal King of Arms (George Bellew), asked the audience in each direction of the compass separately: "Sirs, I here present unto you Queen Elizabeth, your undoubted Queen: wherefore all you who are come this day to do your homage and service, are you willing to do the same?" The crowd would reply "God save Queen Elizabeth" every time,[42] to each of which the Queen would curtsey in return.[39]

Seated again on the Chair of Estate, Elizabeth then took the Coronation Oath as administered by the Archbishop of Canterbury. In the lengthy oath, the Queen swore to govern each of her countries according to their respective laws and customs, to mete out law and justice with mercy, to uphold Protestantism in the United Kingdom and protect the Church of England and preserve its bishops and clergy. She proceeded to the altar where she stated, "The things which I have here promised, I will perform, and keep. So help me God", before kissing the Bible and putting the royal sign-manual to the oath as the Bible was returned to the Dean of Westminster.[43] From him the Moderator of the General Assembly of the Church of Scotland, James Pitt-Watson, took the Bible and presented it to the Queen again, saying,

Our gracious Queen: to keep your Majesty ever mindful of the law and the Gospel of God as the Rule for the whole life and government of Christian Princes, we present you with this Book, the most valuable thing that this world affords. Here is Wisdom; This is the royal Law; These are the lively Oracles of God.

Elizabeth returned the book to Pitt-Watson, who placed it back with the Dean of Westminster.[44]

The communion service was then conducted, involving prayers by both the clergy and Elizabeth, Fisher asking, "O God... Grant unto this thy servant Elizabeth, our Queen, the spirit of wisdom and government, that being devoted unto thee with her whole heart, she may so wisely govern, that in her time thy Church may be in safety, and Christian devotion may continue in peace", before reading various excerpts from the First Epistle of Peter, Psalms, and the Gospel of Matthew.[45] Elizabeth was then anointed as the assembly sang "Zadok the Priest"; the Queen's jewellery and crimson cape were removed by the Earl of Ancaster and the Mistress of the Robes,[11] the Duchess of Devonshire and, wearing only a simple, white linen dress also designed by Hartnell to completely cover the coronation gown, she moved to be seated in the Coronation Chair. There, Fisher, assisted by the Dean of Westminster, made a cross on the Queen's forehead with holy oil made from the same base as had been used in the coronation of her father.[19]  At the Queen's request, the actual anointing ceremony was not televised.[46]

From the altar, the Dean passed to the Lord Great Chamberlain the spurs, which were presented to the Queen and then placed back on the altar. The Sword of State was then handed to Elizabeth, who, after a prayer was uttered by Fisher, placed it herself on the altar, and the peer who had been previously holding it took it back again after paying a sum of 100 shillings.[47] The Queen was then invested with the Armills (bracelets), Stole Royal, Robe Royal and the Sovereign's Orb, followed by the Queen's Ring, the Sovereign's Sceptre with Cross and the Sovereign's Sceptre with Dove. With the first two items on and in her right hand and the latter in her left, Queen Elizabeth was crowned by the Archbishop of Canterbury, with the crowd chanting "GOD SAVE THE QUEEN!!!" three times at the exact moment St Edward's Crown touched the monarch's head. The princes and peers gathered then put on their coronets and a 21-gun salute was fired from the Tower of London.[48]

With the benediction read, Elizabeth moved to the throne and the Archbishop of Canterbury and all the Bishops offered to her their fealty, after which, while the choir sang, the peers of the United Kingdom—led by the royal peers: the Queen's husband; Prince Henry, Duke of Gloucester; and Prince Edward, Duke of Kent—each proceeded, in order of precedence, to pay their personal homage and allegiance to Elizabeth.

When the last baron had completed this task, the assembly shouted "God save Queen Elizabeth. Long live Queen Elizabeth. May the Queen live for ever!"[49] Having removed all her royal regalia, Elizabeth knelt and took the communion, including a general confession and absolution, and, along with the congregation, recited the Lord's Prayer.[50]

Now wearing the Imperial State Crown and holding the Sceptre with the Cross and the Orb, and as the gathered guests sang "God Save the Queen", Elizabeth left Westminster Abbey through the nave and apse, out the Great West Door.

Although many had assumed that the Master of the Queen's Musick, Arnold Bax, would be the director of music for the coronation, it was decided instead to appoint the organist and master of the choristers at the abbey, William McKie, who had been in charge of music at the royal wedding in 1947. McKie convened an advisory committee with Arnold Bax and Sir Ernest Bullock, who had directed the music for the previous coronation.[51]

When it came to choosing the music, tradition required that Handel's "Zadok the Priest" and Parry's "I was glad" were included amongst the anthems. Other choral works included were the 16th century "Rejoice in the Lord alway" and Samuel Sebastian Wesley's "Thou wilt keep him in perfect peace". Another tradition was that new work be commissioned from the leading composers of the day: Ralph Vaughan Williams composed a new motet "O Taste and See", William Walton composed a setting for the "Te Deum", and the Canadian composer Healey Willan wrote an anthem "O Lord our Governor".[26][52] Four new orchestral pieces were planned; Arthur Bliss composed "Processional"; William Walton, "Orb and Sceptre"; and Arnold Bax, "Coronation March". Benjamin Britten had agreed to compose a piece, but he caught influenza and then had to deal with flooding at Aldeburgh, so nothing was forthcoming. Edward Elgar's "Pomp and Circumstance March No. 1 in D" was played immediately before Bax's march at the end of the ceremony.[53] An innovation, at the suggestion of Vaughan Williams, was the inclusion of a hymn in which the congregation could participate. This proved controversial and was not included in the programme until the Queen had been consulted and found to be in favour; Vaughan Williams wrote an elaborate arrangement of the traditional Scottish metrical psalm, "Old 100th", which included military trumpet fanfares.[54] Gordon Jacob wrote a choral arrangement of God Save the Queen, also with trumpet fanfares.[55]

The choir for the coronation was a combination of the choirs of Westminster Abbey, St Paul's Cathedral, the Chapel Royal, and Saint George's Chapel, Windsor. In addition to those established choirs, the Royal School of Church Music conducted auditions to find twenty boy trebles from parish church choirs representing the various regions of the United Kingdom. Along with twelve trebles chosen from various British cathedral choirs, the selected boys spent the month beforehand training at Addington Palace.[56] The final complement of choristers comprised 182 boy trebles, 37 male altos, 62 tenors and 67 basses. Together with a full orchestra, conducted by Sir Adrian Boult, the total number of musicians was 480.[53]

All across the Queen's realms, the rest of the Commonwealth, and in other parts of the world, coronation celebrations were held. The Queen Elizabeth II Coronation Medal was also presented to thousands of recipients throughout the Queen's realms and in Canada, New Zealand, South Africa and the UK, commemorative coins were issued.[57] Three million bronze coronation medallions were ordered by the Canadian government, struck by the Royal Canadian Mint and distributed to schoolchildren across the country; the obverse showed Elizabeth's effigy and the reverse the royal cypher above the word CANADA, all circumscribed by ELIZABETH II REGINA CORONATA MCMLIII.[58]

As at the coronation of George VI, acorns shed from oaks in Windsor Great Park, near Windsor Castle, were shipped around the Commonwealth and planted in parks, school grounds, cemeteries and private gardens to grow into what are known as Royal Oaks or Coronation Oaks.[59]

In London, the Queen hosted a coronation luncheon, for which the recipe coronation chicken was devised,[60] and a fireworks show was mounted on Victoria Embankment.[27] Further, street parties were mounted around the United Kingdom. The Coronation Cup football tournament was held at Hampden Park, Glasgow in May, and[19] two weeks before the coronation, the children's literary magazine Collins Magazine rebranded itself as The Young Elizabethan.[61] News that Edmund Hillary and Tenzing Norgay had reached the summit of Mount Everest arrived in Britain on Elizabeth's coronation day; the New Zealand, American, and British media dubbed it "a coronation gift for the new Queen".[62]

Military tattoos, horse races, parades, and fireworks displays were mounted in Canada. The country's governor general, Vincent Massey, proclaimed the day a national holiday and presided over celebrations on Parliament Hill in Ottawa, where the Queen's coronation speech was broadcast and her personal royal standard flown from the Peace Tower.[63][64] Later, a public concert was held on Parliament Hill and the Governor General hosted a ball at Rideau Hall.[63] In Newfoundland, 90,000 boxes of sweets were given to children, some having theirs delivered by Royal Canadian Air Force drops, and in Quebec, 400,000 people turned out in Montreal, some 100,000 at Jeanne-Mance Park alone. A multicultural show was put on at Exhibition Place in Toronto, square dances and exhibitions took place in the Prairie provinces and in Vancouver the Chinese community performed a public lion dance.[65] On the Korean Peninsula, Canadian soldiers serving in the Korean War acknowledged the day by firing red, white, and blue coloured smoke shells at the enemy and drank rum rations.

On 15 June 1953, the Queen attended a fleet review at Spithead, off the coast at Portsmouth. There were more Commonwealth naval ships present than at the 1937 coronation review, though a third of them were frigates or smaller vessels. Major Royal Navy units included Britain's last battleship, HMS Vanguard, and four fleet and three light aircraft carriers. The Royal Australian Navy and the Royal Canadian Navy also each included a light carrier in their contingents.[66] Using the frigate HMS Surprise as a royal yacht, the Queen and royal family started to review the lines of anchored ships at 3:30 pm, finally anchoring at 5:10 pm. This was followed by a fly-past of some 300 naval aircraft. After the Queen transferred to Vanguard for dinner, the day concluded with the Illumination of the fleet and a fireworks display.[67]


where did fake it till you make it come from

"Fake it 'til you make it" is a common English idiom, which suggests that by imitating confidence, competence, and an optimistic mindset, a person can realize those qualities in their real life. It echoes the underlying principles of cognitive behavioral therapy (CBT) as a means to enable a change in one's behavior.

Fake it 'til you make it

The phrase "fake it 'til you make it" is similar in meaning to the idiom "act as if", and is also similar to Aristotle's idea that to be virtuous, one must act as a virtuous person would act.

In the 1920s, Alfred Adler, a disciple of Sigmund Freud, developed a therapeutic technique that he called "acting as if". This strategy gave his clients an opportunity to practice alternatives to dysfunctional behaviors. Adler's method is still used today and is often described as "role play".


who said lets go to the video tape

Warner William Wolf (born November 11, 1937) is an American television and radio sports broadcaster, perhaps best known as a local news sports anchor in Washington, D.C. and New York City, and for his catchphrase "Let's go to the videotape!"

Warner Wolf

Wolf was born in Washington, D.C., the son of Rosemary and Jack Wolf. His father, an actor and comedian who briefly worked as a member of Ted Healy's "stooge" act, was born Jewish and his mother converted to Judaism.[2][3] His earliest experience in broadcasting was on the intercom system of Calvin Coolidge High School in Washington, D.C. in the 1950s. His upbeat, entertaining patter that was to become his trademark made his sports report a welcome treat for the kids.  During this period he worked part-time at Baker's Shoe Store downtown, as a salesman.  Many customers must have been puzzled at the ball park hawker's refrain of, "Get your hot dogs, get your hot doggies here" coming from the back store room.  He was simply entertaining the staff and the customers, something he was to continue throughout his long career.

Wolf began as a radio broadcaster on April 1, 1961, doing news, weather, and sports for WLSI-AM in Pikeville, Kentucky under the name Ken Wolf. He then moved on to radio jobs in Martinsburg, West Virginia at WEPM, and Washington, D.C. at WTOP-AM before landing a sports television role in 1965 at WTOP-TV (now WUSA) in Washington. There he became very well known and popular as the news sports anchor; he also did play-by-play announcing of local college and professional sports. He retained his job as sports director at WTOP-AM throughout the 1960s, even announcing occasionally on radio broadcasts of Washington Senators games.

In 1976, Wolf gained an ABC Sports network role, working on Monday Night Baseball telecasts and as a host for coverage of football and the Olympics. Wolf's reception in those jobs was mixed, and he decided that he was best at the local news sports anchor role.

Still under contract with ABC, Wolf returned to local sportscasting with a job at WABC-TV in New York in 1976, and then in 1980 moved to rival station WCBS-TV.  His move to WCBS-TV resulted in a lawsuit, American Broadcasting Co. v. Wolf, in which ABC alleged that Wolf failed to negotiate in good faith and sought specific performance of their contract which would have kept Wolf off the air for two years.  The New York Court of Appeals rejected ABC's argument, although they permitted ABC to seek relief in the form of monetary damages.  He also broadcast live sports reports for Israeli television during the 1991 Gulf War.

Wolf returned to Washington as the sports anchor at WUSA, the former WTOP-TV, in June 1992. Wolf succeeded Glenn Brenner, who died earlier that year and had replaced Wolf back in 1977 when he joined ABC Sports. He was dismissed in August 1995. Between November 1995 and December 1996, Wolf was the guest host of The Tony Kornheiser Show on Thursdays on WTEM and sometimes he also flew to New York as a substitute sports anchor on Imus in the Morning when the regular sports anchor, Mike Breen, was away. Because of his work on Imus in the Morning and Don Imus' recommendation on the air continuously, Wolf went back to WCBS-TV as the sports anchor on February 3, 1997 (the most recent of his replacements at WCBS, Bernie Smilovitz, had returned to WDIV in Detroit after having been caught in WCBS' infamous 1996 mass firings).

During this time he also continued to do some work in radio, giving sports reports on the nationally syndicated Imus in the Morning program. Wolf broke the news of the September 11, 2001 attacks on the Imus show, when he saw the World Trade Center on fire from his Lower Manhattan apartment.  Wolf also covered the story for WCBS-TV (where he was working at the time).

He stayed there until May 2004, returning to WABC (AM) in 2006 as the sports reporter for Curtis and Kuby, and continuing, with a two-week hiatus, on the Imus in the Morning program following Don Imus's arrival at WABC (AM). He served as Imus's sports contributor until November 3, 2016, when Imus decided to replace Wolf with Sid Rosenberg.[4] Wolf sued Imus alleging age discrimination.[5]

On May 27, 2004 Wolf was fired by WCBS-TV general manager Lew Leone three months before his contract expired, and replaced by a much younger anchor, Chris Wragge. The day after his firing, his picture covered half the front page of the New York Daily News with the other half being covered by the headline "WOLF FANS RAISE A HOWL".

A few months after his firing, which generated much public outcry, Wolf was hired by radio station WABC and he appeared weekday mornings with Curtis Sliwa & Ron Kuby as well as Mark Simone's Saturday morning radio program. When Imus in the Morning returned to WABC in December 2007, Wolf was not the sports anchor: Tony Powell took that position. But after several weeks Wolf returned to his old position and continued as the morning sports anchor for the Imus in the Morning show. Wolf also hosted a Saturday sports talk show on 1050 ESPN Radio. Wolf modified his trademark "Let's go to the videotape!" to "Let's go to the audiotape!"

Wolf's final day with the Imus show was November 4, 2016. He stayed at WABC until December 3, when his current contract expired.[6]

Wolf played himself in the film Rocky IV and has made several other cameo appearances.  He is the author of the books Let's Go to the Videotape and Give Me a Break.


which type of break is most common in commercial vehicles

Hydraulically actuated disc brakes are the most commonly used form of brake for motor vehicles, but the principles of a disc brake are applicable to almost any rotating shaft.

Disc brake

A disc brake is a type of brake that uses calipers to squeeze pairs of pads against a disc or "rotor"[1] to create friction.[2] This action retards the rotation of a shaft, such as a vehicle axle, either to reduce its rotational speed or to hold it stationary. The energy of motion is converted into waste heat which must be dispersed.

Development of disc-type brakes began in England in the 1890s. In 1902, the Lanchester Motor Company designed brakes that looked and operated in a similar way to a modern disc-brake system even though the disc was thin and a cable activated the brake pad.[3] Other designs they were not practical or widely available in cars for another 60 years. Successful application began in airplanes before World War II, and even the German Tiger tank was fitted with discs in 1942. After the war, technological progress began to arrive in the 1950s, leading to a critical demonstration of superiority at the 1953 24 Hours of Le Mans race, which required braking from high speeds several times per lap. The Jaguar racing team won, using disc brake equipped cars, with much of the credit being given to the brakes' superior performance over rivals equipped with drum brakes. Mass production began with the 1955 Citroën DS.

Compared to drum brakes, disc brakes offer better stopping performance because the disc is more readily cooled. As a consequence discs are less prone to the brake fade caused when brake components overheat. Disc brakes also recover more quickly from immersion (wet brakes are less effective than dry ones).

Most drum brake designs have at least one leading shoe, which gives a servo-effect. By contrast, a disc brake has no self-servo effect and its braking force is always proportional to the pressure placed on the brake pad by the braking system via any brake servo, braking pedal, or lever. This tends to give the driver better "feel" and helps to avoid impending lockup. Drums are also prone to "bell mouthing" and trap worn lining material within the assembly, both causes of various braking problems.

The disc is usually made of cast iron, but may in some cases be made of composites such as reinforced carbon–carbon or ceramic matrix composites. This is connected to the wheel and/or the axle. To retard the wheel, friction material in the form of brake pads, mounted on the brake caliper, is forced mechanically, hydraulically, pneumatically, or electromagnetically against both sides of the disc. Friction causes the disc and attached wheel to slow or stop.

Development of disc brakes began in England in the 1890s.

The first caliper-type automobile disc brake was patented by Frederick William Lanchester in his Birmingham factory in 1902 and used successfully on Lanchester cars. However, the limited choice of metals in this period meant that he had to use copper as the braking medium acting on the disc. The poor state of the roads at this time, no more than dusty, rough tracks, meant that the copper wore quickly making the system impractical.[3]

Successful application began in airplanes and tanks before and during World War II. In Britain, the Daimler Company used disc brakes on its Daimler Armoured Car of 1939, the disc brakes, made by the Girling company, were necessary because in that four-wheel drive (4x4) vehicle the epicyclic final drive was in the wheel hubs and therefore left no room for conventional hub-mounted drum brakes.[4]

At Germany's Argus Motoren, Hermann Klaue (1912-2001) had patented[5] disc brakes in 1940. Argus supplied wheels fitted with disc brakes e.g. for the Arado Ar 96.[6] The German Tiger I heavy tank, was introduced in 1942 with a 55Â cm Argus-Werke disc[7] on each drive shaft.

The American Crosley Hot Shot is often given credit for the first production disc brakes. For six months in 1950, Crosley built a car with these brakes, then returned to drum brakes. Lack of sufficient research caused reliability problems, such as sticking and corrosion, especially in regions using salt on winter roads.[8] Drum brake conversions for Hot Shots were quite popular.[8] The Crosley disc was a Goodyear development, a caliper type with ventilated disc, originally designed for aircraft applications.[3]

Chrysler developed a unique braking system, offered from 1949 to 1953. Instead of the disc with caliper squeezing on it, this system used twin expanding discs that rubbed against the inner surface of a cast-iron brake drum, which doubled as the brake housing.[8] The discs spread apart to create friction against the inner drum surface through the action of standard wheel cylinders.[8] Because of the expense, the brakes were only standard on the Chrysler Crown and the Town and Country Newport in 1950.[8] They were optional, however, on other Chryslers, priced around $400, at a time when an entire Crosley Hot Shot retailed for $935.[8] This four-wheel disc brake system was built by Auto Specialties Manufacturing Company (Ausco) of St. Joseph, Michigan, under patents of inventor H.L. Lambert, and was first tested on a 1939 Plymouth.[8] Chrysler discs were "self energizing," in that some of the braking energy itself contributed to the braking effort.[8] This was accomplished by small balls set into oval holes leading to the brake surface.[8] When the disc made initial contact with the friction surface, the balls would be forced up the holes forcing the discs further apart and augmenting the braking energy.[8] This made for lighter braking pressure than with calipers, avoided brake fade, promoted cooler running, and provided one-third more friction surface than standard Chrysler twelve-inch drums.[8] Today's owners consider the Ausco-Lambert very reliable and powerful, but admit its grabbiness and sensitivity.[8]

The first use of disc brakes in racing was in 1951, one of the BRM Type 15s using a Girling-produced set, a first for a Formula One car. Reliable caliper-type disc brakes later appeared in 1953 on the Jaguar C-Type racing car. These brakes helped the company to win the 1953 24 Hours of Le Mans,[9] developed in the UK by Dunlop. That same year, the aluminum bodied Austin-Healey 100S, of which 50 were made, was the first car sold to the public to have disc brakes, fitted to all 4 wheels.[10]

The first mass production use of the modern disc brake was in 1955, on the Citroën DS, which featured caliper-type front disc brakes among its many innovations.[3] These discs were mounted inboard near the transmission, and were powered by the vehicle's central hydraulic system. This model went on to sell 1.5 million units over 20 years with the same brake setup.

The Jensen 541, with four-wheel disc brakes, followed in 1956.[3][11]

Disc brakes were most popular on sports cars when they were first introduced, since these vehicles are more demanding about brake performance. Discs have now become the more common form in most passenger vehicles, although many (particularly light weight vehicles) use drum brakes on the rear wheels to keep costs and weight down as well as to simplify the provisions for a parking brake. As the front brakes perform most of the braking effort, this can be a reasonable compromise.[12]

Many early implementations for automobiles located the brakes on the inboard side of the driveshaft, near the differential, while most brakes today are located inside the wheels. An inboard location reduces the unsprung weight and eliminates a source of heat transfer to the tires.

Historically, brake discs were manufactured throughout the world with a strong concentration in Europe and America. Between 1989 and 2005, manufacturing of brake discs migrated predominantly to China.

After a 10-year hiatus, America built another production automobile equipped with disc brakes - the 1963 Studebaker Avanti[13] (the Bendix system was optional on some of the other Studebaker models[14]). Front disc brakes became standard equipment in 1965 on the Rambler Marlin[15] (the Bendix units were optional on all American Motors' Rambler Classic and Ambassador models[16]), as well as on the Ford Thunderbird,[17] and the Lincoln Continental.[18] A four-wheel disc brake system was also introduced in 1965 on the Chevrolet Corvette Stingray.[19]

The first motorcycles to use disc brakes were racing vehicles. MV Agusta was the first to offer a front disc brake motorcycle to the public on a small scale in 1965, on their relatively expensive 600 touring motorcycle, using a mechanical brake linkage.[20] In 1969 Honda introduced the more affordable CB750, which had a single hydraulically-actuated front disc brake (and a rear drum brake), and which sold in huge numbers.[20] Disc brakes are now common on motorcycles, mopeds and even mountain bikes.

The brake disc (or rotor) is the rotating part of a wheel's disc brake assembly, against which the brake pads are applied. The material is typically gray iron,[21] a form of cast iron. The design of the discs varies somewhat. Some are simply solid, but others are hollowed out with fins or vanes joining together the disc's two contact surfaces (usually included as part of a casting process). The weight and power of the vehicle determines the need for ventilated discs.[16] The "ventilated" disc design helps to dissipate the generated heat and is commonly used on the more-heavily loaded front discs.

Discs for motorcycles, bicycles, and many cars often have holes or slots cut through the disc. This is done for better heat dissipation, to aid surface-water dispersal, to reduce noise, to reduce mass, or for marketing cosmetics.

Slotted discs have shallow channels machined into the disc to aid in removing dust and gas. Slotting is the preferred method in most racing environments to remove gas and water and to deglaze brake pads. Some discs are both drilled and slotted. Slotted discs are generally not used on standard vehicles because they quickly wear down brake pads; however, this removal of material is beneficial to race vehicles since it keeps the pads soft and avoids vitrification of their surfaces. On the road, drilled or slotted discs still have a positive effect in wet conditions because the holes or slots prevent a film of water building up between the disc and the pads.

A floating disc is splined, rather than rigidly fixed, to the hub as a way of avoiding thermal stress, cracking and warping. This allows the disc to expand in a controlled symmetrical way and with less unwanted heat transfer to the hub.

Lambretta introduced the first high-volume production use of a single, floating, front disc brake, enclosed in a ventilated cast alloy hub and actuated by cable, on the 1962 TV175,[22] followed by the range-topping GT200 in 1964.[23][24][25][26] The 1969 Honda CB750 introduced hydraulic disc brakes on a large scale to the wide motorcycle public, following the lesser known 1965 MV Agusta 600, which had cable-operated mechanical actuation.[20][27]

Unlike car disc brakes that are buried within the wheel, bike disc brakes are in the airstream and have optimum cooling. Although cast iron discs have a porous surface which give superior braking performance, such discs rust in the rain and become unsightly. Accordingly, motorcycle discs are usually stainless steel, drilled, slotted or wavy to disperse rain water. Modern motorcycle discs tend to have a floating design whereby the disc "floats" on bobbins and can move slightly, allowing better disc centering with a fixed caliper. A floating disc also avoids disc warping and reduces heat transfer to the wheel hub. Calipers have evolved from simple single-piston units to two-, four- and even six-piston items.[28] Compared to cars, motorcycles have a higher center of mass:wheelbase ratio, so they experience more weight transfer when braking. Front brakes absorb most of the braking forces, while the rear brake serves mainly to balance the motorcycle during braking. Modern sport bikes typically have twin large front discs, with a much smaller single rear disc. Bikes that are particularly fast or heavy may have vented discs.

Early disc brakes (such as on the early Honda fours and the Norton Commando) sited the calipers on top of the disc, ahead of the fork slider. Although this gave the brake pads better cooling, it is now almost universal practice to site the caliper behind the slider (to reduce the angular momentum of the fork assembly). Rear disc calipers may be mounted above (e.g. BMW R1100S) or below (e.g. Yamaha TRX850) the swinging arm: a low mount is marginally better for CG purposes, while an upper siting keeps the caliper cleaner and better-protected from road obstacles.

A modern development, particularly on inverted ("upside down", or "USD") forks is the radially mounted caliper. Although these are fashionable, there is no evidence that they improve braking performance, nor do they add to the stiffness of the fork. (Lacking the option of a fork brace, USD forks may be best stiffened by an oversize front axle).[citation needed]

Mountain bike disc brakes may range from simple, mechanical (cable) systems, to expensive and powerful, multi-piston hydraulic disc systems, commonly used on downhill racing bikes. Improved technology has seen the creation of vented discs for use on mountain bikes, similar to those on cars, introduced to help avoid heat fade on fast alpine descents. Although less common, discs are also used on road bicycles for all-weather cycling with predictable braking, although drums are sometimes preferred as harder to damage in crowded parking, where discs are sometimes bent. Most bicycle brake discs are made of steel. Stainless steel is preferred due to its anti-rust properties.[29] Discs are thin, often about 2Â mm. Some use a two-piece floating disc style, others use a floating caliper, others use pads that float in the caliper, and some use one moving pad that makes the caliper slide on its mounts, pulling the other pad into contact with the disc.[citation needed] Because the "motor" is small, an uncommon feature of bicycle brakes is that the pads retract to eliminate residual drag when the brake is released.[clarification needed] In contrast, most other brakes drag the pads lightly when released so as to minimise initial operational travel.[clarification needed]

Disc brakes are increasingly used on very large and heavy road vehicles, where previously large drum brakes were nearly universal. One reason is that the disc's lack of self-assist makes brake force much more predictable, so peak brake force can be raised without more risk of braking-induced steering or jackknife on articulated vehicles. Another is disc brakes fade less when hot, and in a heavy vehicle air and rolling drag and engine braking are small parts of total braking force, so brakes are used harder than on lighter vehicles, and drum brake fade can occur in a single stop. For these reasons, a heavy truck with disc brakes can stop in about 120% the distance of a passenger car, but with drums stopping takes about 150% the distance.[30] In Europe, stopping distance regulations essentially require disc brakes for heavy vehicles. In the U.S., drums are allowed and are typically preferred for their lower purchase price, despite higher total lifetime cost and more frequent service intervals.[citation needed]

Still-larger discs are used for railroad cars and some airplanes. Passenger rail cars and light rail vehicles often use disc brakes outboard of the wheels, which helps ensure a free flow of cooling air. However, on some modern passenger rail cars, such as the Amfleet II cars, inboard disc brakes are used. This reduces wear from debris, and also provides protection from rain and snow, which would make the discs slippery, and unreliable. However, there is still plenty of cooling for reliable operation. In contrast, some airplanes have the brake mounted with very little cooling and the brake gets quite hot in a stop, but this is acceptable as there is then time for cooling, and where the maximum braking energy is very predictable.

For automotive use, disc brake discs are commonly manufactured out of a material called grey iron.[21] The SAE maintains a specification for the manufacture of grey iron for various applications. For normal car and light-truck applications, SAE specification J431 G3000 (superseded to G10) dictates the correct range of hardness, chemical composition, tensile strength, and other properties necessary for the intended use. Some racing cars and airplanes use brakes with carbon fiber discs and carbon fiber pads to reduce weight. Wear rates tend to be high, and braking may be poor or grabby until the brake is hot. For this reason, many performance-oriented vehicles or trucks that tow something overweight are equipped with the slotted or vented rotors. Such upgrades eliminate excessive heat and remove contaminants that may interfere with gripping power.[31] Usually performance rotors are installed as an aftermarket upgrade or come as a part of a performance package in certain trim levels from the factory. The main drawback of the vented and slotted rotors is high wear.

In racing and very-high-performance road cars, other disc materials have been employed. Reinforced carbon discs and pads inspired by aircraft braking systems such as those used on Concorde were introduced in Formula One by Brabham in conjunction with Dunlop in 1976.[32] Carbon–carbon braking is now used in most top-level motorsport worldwide, reducing unsprung weight, giving better frictional performance and improved structural properties at high temperatures, compared to cast iron. Carbon brakes have occasionally been applied to road cars, by the French Venturi sports car manufacturer in the mid 1990s for example, but need to reach a very high operating temperature before becoming truly effective and so are not well suited to road use. The extreme heat generated in these systems is easily visible during night racing, especially at shorter tracks. It is not uncommon to be able to look at the cars, either live in person or on television and see the brake discs glowing red during application.

Ceramic discs are used in some high-performance cars and heavy vehicles.

The first development of the modern ceramic brake was made by British engineers working in the railway industry for TGV applications in 1988. The objective was to reduce weight, the number of brakes per axle, as well as provide stable friction from very high speeds and all temperatures. The result was a carbon-fibre-reinforced ceramic process which is now used in various forms for automotive, railway, and aircraft brake applications.

Due to the high heat tolerance and mechanical strength of ceramic composite discs, they are often used on exotic vehicles where the cost is not prohibitive to the application. They are also found in industrial applications where the ceramic disc's light weight and low-maintenance properties justify the cost relative to alternatives. Composite brakes can withstand temperatures that would make steel discs bendable.

Porsche's Composite Ceramic Brakes (PCCB) are siliconized carbon fiber, with very high temperature capability, a 50% weight reduction over iron discs (therefore reducing the unsprung weight of the vehicle), a significant reduction in dust generation, substantially increased maintenance intervals, and enhanced durability in corrosive environments over conventional iron discs. Found on some of their more expensive models, it is also an optional brake for all street Porsches at added expense. It is generally recognized by the bright yellow paintwork on the aluminum six-piston calipers that are matched with the discs. The discs are internally vented much like cast-iron ones, and cross-drilled.

In automotive applications, the piston seal has a square cross section, also known as a square-cut seal.

As the piston moves in and out, the seal drags and stretches on the piston, causing the seal to twist. The seal distorts approximately 1/10 of a millimeter. The piston is allowed to move out freely, but the slight amount of drag caused by the seal stops the piston from fully retracting to its previous position when the brakes are released, and so takes up the slack caused by the wear of the brake pads, eliminating the need for return springs.[33][34]

In some rear disc calipers, the parking brake activates a mechanism inside the caliper that performs some of the same function.

Discs are usually damaged in one of four ways: scarring, cracking, warping or excessive rusting. Service shops will sometimes respond to any disc problem by changing out the discs entirely, This is done mainly where the cost of a new disc may actually be lower than the cost of labour to resurface the old disc. Mechanically this is unnecessary unless the discs have reached manufacturer's minimum recommended thickness, which would make it unsafe to use them, or vane rusting is severe (ventilated discs only). Most leading vehicle manufacturers recommend brake disc skimming (US: turning) as a solution for lateral run-out, vibration issues and brake noises. The machining process is performed in a brake lathe, which removes a very thin layer off the disc surface to clean off minor damage and restore uniform thickness. Machining the disc as necessary will maximise the mileage out of the current discs on the vehicle.

Run-out is measured using a dial indicator on a fixed rigid base, with the tip perpendicular to the brake disc's face. It is typically measured about 1⁄2 in (12.7 mm) from the outside diameter of the disc. The disc is spun. The difference between minimum and maximum value on the dial is called lateral run-out. Typical hub/disc assembly run-out specifications for passenger vehicles are around 0.002 in (0.0508 mm). Runout can be caused either by deformation of the disc itself or by runout in the underlying wheel hub face or by contamination between the disc surface and the underlying hub mounting surface. Determining the root cause of the indicator displacement (lateral runout) requires disassembly of the disc from the hub. Disc face runout due to hub face runout or contamination will typically have a period of 1 minimum and 1 maximum per revolution of the brake disc.

Discs can be machined to eliminate thickness variation and lateral run-out. Machining can be done in situ (on-car) or off-car (bench lathe). Both methods will eliminate thickness variation. Machining on-car with proper equipment can also eliminate lateral run-out due to hub-face non-perpendicularity.

Incorrect fitting can distort (warp) discs; the disc's retaining bolts (or the wheel/lug nuts, if the disc is simply sandwiched in place by the wheel, as on many cars) must be tightened progressively and evenly. The use of air tools to fasten lug nuts can be bad practice, unless a torque wrench is also used for final tightening. The vehicle manual will indicate the proper pattern for tightening as well as a torque rating for the bolts. Lug nuts should never be tightened in a circle. Some vehicles are sensitive to the force the bolts apply and tightening should be done with a torque wrench.

Often uneven pad transfer is confused for disc warping.[35] In reality, the majority of brake discs which are diagnosed as "warped" are actually simply the product of uneven transfer of pad material. Uneven pad transfer will often lead to a thickness variation of the disc. When the thicker section of the disc passes between the pads, the pads will move apart and the brake pedal will raise slightly; this is pedal pulsation. The thickness variation can be felt by the driver when it is approximately 0.17 mm (0.0067 in) or greater (on automobile discs).

This type of thickness variation has many causes, but there are three primary mechanisms which contribute the most to the propagation of disc thickness variations connected to uneven pad transfer. The first is improper selection of brake pads for a given application. Pads which are effective at low temperatures, such as when braking for the first time in cold weather, often are made of materials which decompose unevenly at higher temperatures. This uneven decomposition results in uneven deposition of material onto the brake disc. Another cause of uneven material transfer is improper break in of a pad/disc combination. For proper break in, the disc surface should be refreshed (either by machining the contact surface or by replacing the disc as a whole) every time the pads are changed on a vehicle. Once this is done, the brakes are heavily applied multiple times in succession. This creates a smooth, even interface between the pad and the disc. When this is not done properly the brake pads will see an uneven distribution of stress and heat, resulting in an uneven, seemingly random, deposition of pad material. The third primary mechanism of uneven pad material transfer is known as "pad imprinting." This occurs when the brake pads are heated to the point that the material begins to break-down and transfer to the disc. In a properly broken in brake system (with properly selected pads), this transfer is natural and actually is a major contributor to the braking force generated by the brake pads. However, if the vehicle comes to a stop and the driver continues to apply the brakes, the pads will deposit a layer of material in the shape of the brake pad. This small thickness variation can begin the cycle of uneven pad transfer.

Once the disc has some level of variation in thickness, uneven pad deposition can accelerate, sometimes resulting in changes to the crystal structure of the metal that composes the disc in extreme situations. As the brakes are applied, the pads slide over the varying disc surface. As the pads pass by the thicker section of the disc, they are forced outwards. The foot of the driver applied to the brake pedal naturally resists this change, and thus more force is applied to the pads. The result is that the thicker sections see higher levels of stress. This causes an uneven heating of the surface of the disc, which causes two major issues. As the brake disc heats unevenly it also expands unevenly. The thicker sections of the disc expand more than the thinner sections due to seeing more heat, and thus the difference in thickness is magnified. Also, the uneven distribution of heat results in further uneven transfer of pad material. The result is that the thicker-hotter sections receive even more pad material than the thinner-cooler sections, contributing to a further increase in the variation in the disc's thickness. In extreme situations, this uneven heating can actually cause the crystal structure of the disc material to change. When the hotter sections of the discs reach extremely high temperatures (1,200–1,300 °F or 649–704 °C ), the metal can undergo a phase transformation and the carbon which is dissolved in the steel can precipitate out to form carbon-heavy carbide regions known as cementite. This iron carbide is very different from the cast iron the rest of the disc is composed of. It is extremely hard, very brittle, and does not absorb heat well. After cementite is formed, the integrity of the disc is compromised. Even if the disc surface is machined, the cementite within the disc will not wear or absorb heat at the same rate as the cast iron surrounding it, causing the uneven thickness and uneven heating characteristics of the disc to return.

Scarring (US: Scoring) can occur if brake pads are not changed promptly when they reach the end of their service life and are considered worn out. Once enough of the friction material has worn away, the pad's steel backing plate (for glued pads) or the pad retainer rivets (for riveted pads) will bear directly upon the disc's wear surface, reducing braking power and making scratches on the disc. Generally a moderately scarred / scored disc, which operated satisfactorily with existing brake pads, will be equally usable with new pads. If the scarring is deeper but not excessive, it can be repaired by machining off a layer of the disc's surface. This can only be done a limited number of times as the disc has a minimum rated safe thickness. The minimum thickness value is typically cast into the disc during manufacturing on the hub or the edge of the disc. In Pennsylvania, which has one of the most rigorous auto safety inspection programs in North America, an automotive disc cannot pass safety inspection if any scoring is deeper than.015 inches (0.38Â mm), and must be replaced if machining will reduce the disc below its minimum safe thickness.

To prevent scarring, it is prudent to periodically inspect the brake pads for wear. A tire rotation is a logical time for inspection, since rotation must be performed regularly based on vehicle operation time and all wheels must be removed, allowing ready visual access to the brake pads. Some types of alloy wheels and brake arrangements will provide enough open space to view the pads without removing the wheel. When practical, pads that are near the wear-out point should be replaced immediately, as complete wear out leads to scarring damage and unsafe braking. Many disc brake pads will include some sort of soft steel spring or drag tab as part of the pad assembly, which is designed to start dragging on the disc when the pad is nearly worn out. The result is a moderately loud metallic squealing noise, alerting the vehicle user that service is required, and this will not normally scar the disc if the brakes are serviced promptly. A set of pads can be considered for replacement if the thickness of the pad material is the same or less than the thickness of the backing steel. In Pennsylvania, the standard is 1/32".

Cracking is limited mostly to drilled discs, which may develop small cracks around edges of holes drilled near the edge of the disc due to the disc's uneven rate of expansion in severe duty environments. Manufacturers that use drilled discs as OEM typically do so for two reasons: appearance, if they determine that the average owner of the vehicle model will prefer the look while not overly stressing the hardware; or as a function of reducing the unsprung weight of the brake assembly, with the engineering assumption that enough brake disc mass remains to absorb racing temperatures and stresses. A brake disc is a heat sink, but the loss of heat sink mass may be balanced by increased surface area to radiate away heat. Small hairline cracks may appear in any cross drilled metal disc as a normal wear mechanism, but in the severe case the disc will fail catastrophically. No repair is possible for the cracks, and if cracking becomes severe, the disc must be replaced. These cracks occur due to the phenomenon of low cycle fatigue as a result of repeated hard braking.[36]

The discs are commonly made from cast iron and a certain amount of surface rust is normal. The disc contact area for the brake pads will be kept clean by regular use, but a vehicle that is stored for an extended period can develop significant rust in the contact area that may reduce braking power for a time until the rusted layer is worn off again. Rusting can also lead to disc warping when brakes are re-activated after storage because of differential heating between unrusted areas left covered by pads and rust around the majority of the disc area surface. Over time, vented brake discs may develop severe rust corrosion inside the ventilation slots, compromising the strength of the structure and needing replacement.[37]

The brake caliper is the assembly which houses the brake pads and pistons. The pistons are usually made of plastic, aluminium or chrome-plated steel.

Calipers are of two types, floating or fixed. A fixed caliper does not move relative to the disc and is thus less tolerant of disc imperfections. It uses one or more pairs of opposing pistons to clamp from each side of the disc, and is more complex and expensive than a floating caliper.

A floating caliper (also called a "sliding caliper") moves with respect to the disc, along a line parallel to the axis of rotation of the disc; a piston on one side of the disc pushes the inner brake pad until it makes contact with the braking surface, then pulls the caliper body with the outer brake pad so pressure is applied to both sides of the disc. Floating caliper (single piston) designs are subject to sticking failure, caused by dirt or corrosion entering at least one mounting mechanism and stopping its normal movement. This can lead to the caliper's pads rubbing on the disc when the brake is not engaged or engaging it at an angle. Sticking can result from infrequent vehicle use, failure of a seal or rubber protection boot allowing debris entry, dry-out of the grease in the mounting mechanism and subsequent moisture incursion leading to corrosion, or some combination of these factors. Consequences may include reduced fuel efficiency, extreme heating of the disc or excessive wear on the affected pad. A sticking front caliper may also cause steering vibration.

Another type of floating caliper is a swinging caliper. Instead of a pair of horizontal bolts that allow the caliper to move straight in and out respective to the car body, a swinging caliper utilizes a single, vertical pivot bolt located somewhere behind the axle centerline. When the driver presses the brakes, the brake piston pushes on the inside piston and rotates the whole caliper inward, when viewed from the top. Because the swinging caliper's piston angle changes relative to the disc, this design uses wedge-shaped pads that are narrower in the rear on the outside and narrower on the front on the inside.

Various types of brake calipers are also used on bicycle rim brakes.

The most common caliper design uses a single hydraulically actuated piston within a cylinder, although high performance brakes use as many as twelve. Modern cars use different hydraulic circuits to actuate the brakes on each set of wheels as a safety measure. The hydraulic design also helps multiply braking force. The number of pistons in a caliper is often referred to as the number of 'pots', so if a vehicle has'six pot' calipers it means that each caliper houses six pistons.

Brake failure can result from failure of the piston to retract, which is usually a consequence of not operating the vehicle during prolonged storage outdoors in adverse conditions. On high-mileage vehicles, the piston seals may leak, which must be promptly corrected.

Brake pads are designed for high friction with brake pad material embedded in the disc in the process of bedding while wearing evenly. Friction can be divided into two parts. They are: adhesive and abrasive.

Depending on the properties of the material of both the pad and the disc and the configuration and the usage, pad and disc wear rates will vary considerably. The properties that determine material wear involve trade-offs between performance and longevity.

The brake pads must usually be replaced regularly (depending on pad material, and drivestyle), and some are equipped with a mechanism that alerts drivers that replacement is needed, such as a thin piece of soft metal that rubs against the disc when the pads are too thin causing the brakes to squeal, a soft metal tab embedded in the pad material that closes an electric circuit and lights a warning light when the brake pad gets thin, or an electronic sensor.

Generally road-going vehicles have two brake pads per caliper, while up to six are installed on each racing caliper, with varying frictional properties in a staggered pattern for optimum performance.

Early brake pads (and linings) contained asbestos, producing dust which should not be inhaled. Although newer pads can be made of ceramics, Kevlar, and other plastics, inhalation of brake dust should still be avoided regardless of material.

Sometimes a loud noise or high pitched squeal occurs when the brakes are applied. Most brake squeal is produced by vibration (resonance instability) of the brake components, especially the pads and discs (known as force-coupled excitation). This type of squeal should not negatively affect brake stopping performance. Techniques include adding chamfer pads to the contact points between caliper pistons and the pads, the bonding insulators (damping material) to pad backplate, the brake shims between the brake pad and pistons, etc. All should be coated with an extremely high temperature, high solids lubricant to help reduce squeal. This allows the metal to metal parts to move independently of each other and thereby eliminate the buildup of energy that can create a frequency that is heard as brake squeal, groan, or growl. It is inherent that some pads are going to squeal more given the type of pad and its usage case. Pads typically rated to withstand very high temperatures for extended periods tend to produce high amounts of friction leading to more noise during brake application.[38]

Cold weather combined with high early-morning humidity (dew) often worsens brake squeal, although the squeal generally stops when the lining reaches regular operating temperatures. This more strongly affects pads meant to be used at higher temperatures. Dust on the brakes may also cause squeal and commercial brake cleaning products are designed to remove dirt and other contaminants. Pads without a proper amount of transfer material could also squeal, this can be remedied by bedding or re-bedding the brake pads to brake discs.

Some lining wear indicators, located either as a semi-metallic layer within the brake pad material or with an external "sensor", are also designed to squeal when the lining is due for replacement. The typical external sensor is fundamentally different from the noises described above (when the brakes are applied) because the wear sensor noise typically occurs when the brakes are not used. The wear sensor may only create squeal under braking when it first begins to indicate wear but is still a fundamentally different sound and pitch.[38][39]

Brake judder is usually perceived by the driver as minor to severe vibrations transferred through the chassis during braking.[40][41][42][43][44][45][46][47][48]

The judder phenomenon can be classified into two distinct subgroups: hot (or thermal), or cold judder.

Hot judder is usually produced as a result of longer, more moderate braking from high speed where the vehicle does not come to a complete stop.[49] It commonly occurs when a motorist decelerates from speeds of around 120 km/h (74.6 mph) to about 60 km/h (37.3 mph), which results in severe vibrations being transmitted to the driver. These vibrations are the result of uneven thermal distributions, or hot spots. Hot spots are classified as concentrated thermal regions that alternate between both sides of a disc that distort it in such a way that produces a sinusoidal waviness around its edges. Once the brake pads (friction material/brake lining) comes in contact with the sinusoidal surface during braking, severe vibrations are induced, and can produce hazardous conditions for the person driving the vehicle.[50][51][52][53]

Cold judder, on the other hand, is the result of uneven disc wear patterns or disc thickness variation (DTV). These variations in the disc surface are usually the result of extensive vehicle road usage. DTV is usually attributed to the following causes: waviness and roughness of disc surface,[54] misalignment of axis (runout), elastic deflection, wear and friction material transfers.[42][53][55] Either type could potentially fixed by ensuring a clean mounting surface on either side of the brake disc between the wheel hub and brake disc hub before usage and paying attention to imprinting after extended usage by leaving the brake pedal heavily depressed at the end of heavy usage. Sometimes a bed in procedure can clean and minimize DTV and lay a new even transfer layer between the pad and brake disc. However it will not eliminate hot spots or excessive run out.

When braking force is applied, the act of abrasive friction between the brake pad and the disc wears both the disc and pad away. The brake dust that is seen deposited on wheels, calipers and other braking system components consists mostly of disc material.[56] Brake dust can damage the finish of most wheels if not washed off.[57] Generally, a brake pad that aggressively abrades more disc material away, such as metallic pads, will create more brake dust. Some higher performing pads for track use or towing use may wear away much quicker than a typical pad causing additional dust from heightened brake disc wear and brake pad wear.[58]

Brake discs and pads require sometime to adhere to each other smoothly. The pads need to deposit an even transfer layer. For street and urban driving with new pads and discs it is best to treat them as a break in period as you would a new car for 200 to 300 miles after this period the manufactures bedding procedure can be followed. This is typically some number of stops from a certain max speed to a minimum speed. For example, 10 moderate stops from 60 mph to 10 mph in a safe controlled environment where no hazards are present. The goal is to get the brake pads and brake discs hot. During this time it is ideal to keep the brake pressure and stops consistent without engaging the Anti lock braking system or skidding the tires. There will likely be smells and a light amount of smoke. This is normal. Once the brakes begin to suffer from fade(braking effectiveness slightly reduced) the process is complete. Continue to drive at moderate speeds to cool the brake discs avoiding the use of the brakes unless needed for emergency situations. Also take note when coming to a complete stop until everything has cooled not to hold your foot on the brakes which could create an imprint. This procedure can be done at any time during the pad's or rotor's life to attempt to alleviate some of the common issues associated with disc brake systems. Ensure the discs and pads are in adequate shape before attempting a bedding procedure.[59]