Editing Disc brake (section)

===Motorcycles and scooters===
[[File:W800 disk brake.jpg|thumb|Floating disc brake on [[Kawasaki W800]] ]]
[[File:Brembo Disc brake.jpg|thumb|Radially-mounted brake caliper on a [[Triumph Speed Triple]] ]]

[[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.<ref>{{cite web |last1=Watson |first1=Tim |title=Motorcycle History: Brakes |url= https://www.rideapart.com/features/255230/motorcycle-history-brakes/ |website=RideApart.com |date=7 December 2013 |access-date=13 November 2022}}</ref><ref>{{cite web |title=Series 3 (TV) |url=https://www.lambretta.com/classics/series-3-tv/ |website=lambretta.com |access-date=18 February 2024}}</ref> This was followed by the GT200 in 1964.<ref>{{cite magazine |magazine=The Motor Cycle |date=10 September 1964 |page=7 |title=Lambretta (centerspread advertisement)}}</ref><ref>{{cite magazine |magazine=The Motor Cycle |date=25 November 1965 |pages=748–751 |title=Lambretta servicing hints: Disc Brake Adjustment}}</ref><ref>{{cite magazine |magazine=Motorcycle Mechanics |date=April 1969 |title=UK Lambretta Concessionaires (advertisement) |page=19}}</ref><ref>{{cite magazine |magazine=Motorcycle Mechanics |date=October 1969 |pages=45–47 |title=Slowdown Lowdown |first=John |last=Robinson}}</ref> 

[[MV Agusta]] was the second manufacturer to offer a front disc brake motorcycle to the public on a small scale in 1965, on their expensive [[MV Agusta 600|600 touring motorcycle]] featuring cable-operated mechanical actuation.<ref name=Frank2003>{{cite book |title= Honda Motorcycles |first=Aaron |last=Frank |publisher=MotorBooks/MBI |year=2003 |isbn=0-7603-1077-7 |page=80 }}</ref> In 1969, Honda introduced the more affordable [[Honda CB750|CB750]], which had a single hydraulically actuated front disc brake (and a rear drum brake), and which sold in huge numbers.<ref name=Frank2003/><ref>{{cite web |url= http://classicmotorcycles.about.com/od/Glossary/g/Disc-Brakes.htm?ad=semD&an=msn_s&am=exact&q=motorcycle%20disc%20brakes&dqi=&o=4581&l=sem&qsrc=999&askid=c4927c68-01b9-4e24-b46b-c819e854c91f-0-ab_mse |title=Disc Brakes |first=John |last=Glimmerveen |website=About.com Autos |access-date=15 February 2015 }}{{Dead link|date=February 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

Unlike cars, disc brakes that are located within the wheel, bike disc brakes are in the airstream and have optimum cooling. Although cast iron discs have a porous surface that provides 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 rainwater. 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.<ref>{{cite web|url= http://www.motorcycle.com/how-to/disc-brake-tech-3437.html |title=Disc Brake Tech |first=Michael |last=Kresnicka |website=motorcycle.com |date=30 October 2000 |access-date=15 February 2015}}</ref> 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 [[sports motorcycle]]s typically have twin large front discs, with a much smaller single rear disc. Motorcycles 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 provides for a marginally lower center of gravity, while an upper siting keeps the caliper cleaner and better-protected from road obstacles.

One problem with motorcycle disc brakes is that when a motorcycle gets into a violent [[tank-slapper]] (high-speed oscillation of the front wheel) the brake pads in the calipers are forced away from the discs, so when the rider applies the brake lever, the caliper pistons push the pads towards the discs without actually making contact. The rider then brakes harder, forcing the pads onto the disc much more aggressively than standard braking. An example of this was the Michele Pirro incident at Mugello, Italy 1 June 2018.<ref>{{cite web|url= https://www.motorsportmagazine.com/opinion/motogp/motogp-mutterings-mugello |title= Latest MotoGP News • 2021 Season |work=MotorSport Magazine|date= 21 February 2024 }}</ref> At least one manufacturer has developed a system to counter the pads being forced away.

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 or add to the fork's stiffness. (Lacking the option of a fork brace, USD forks may be best stiffened by an oversized front axle).{{citation needed|date=November 2016}}