Motorcycle braking systems

Motorcycle braking systems have varied throughout time, as motorcycles evolved from bicycles with an engine attached, to the 220 mph (350 km/h) prototype motorcycles seen racing in MotoGP. Most systems work by converting kinetic energy into thermal energy (heat) by friction. On motorcycles, approximately 70% of the braking effort is performed by the front brake. This however can vary for individual motorcycles; longer-wheelbase types having more weight biased rearward, such as cruisers and tourers, can have a greater effort applied by the rear brake. In contrast, sports bikes with a shorter wheelbase and more vertical fork geometry can tolerate higher front braking loads. For these reasons, motorcycles tend to have a vastly more powerful front brake compared to the rear.

Early motorcycles which were essentially a bicycle with a motor attached and did not have any braking system beyond cutting the power and waiting for the motorcycle to slow down enough to put a foot out. One of the first motorcycles to have any sort of braking mechanism was made by Steffey Motorcycles of Philadelphia in 1902. This used a spoon brake operating on the front wheel only. Around 1909 band brakes were introduced, these used a band contracting round the outside of a drum.

Douglas motorcycles were available with Research Association disc brakes front and rear on their 1923 RA model, sometimes called TT model, with Freddie Dixon's 1923 sidecar TT-winning machine of that type also having a passenger-operated disc brake for the sidecar wheel.

Drum brakes were first used on motorcycles in the 1920s and the basic design has not changed much. Originally used for braking both the front and rear wheels, drum brakes have largely been superseded by disc brakes or are used for rear-braking only.

The Lambretta TV125 Series 3 was the first modern^{[clarification needed]} production motorcycle with a disc brake. MV Agusta followed with their limited production 600 cc touring motorcycle announced in 1965 which had a pair of cable-actuated Campagnolo front disc brakes. The 1969 Honda CB750 put motorcycle disc brakes into the mass market, using a hydraulically operated single piston sliding caliper with a solid front disc.

Early cast wheels were not easily compatible with drum brakes. Sintered pads offer improved heat up time and better wet weather performance. Asbestos was used in the brake pads but its use declined when the negative health impact was discovered.

In 1989 BMW released the first motorcycle to be equipped with an assisted braking system (ABS). The system fitted to the BMW K100 LT weighed significantly more than the light weight systems fitted to modern motorcycles.

The front suspension on the Yamaha GTS1000 released in 1993 was a single sided swingarm that among other characteristics aimed to reduce diving under braking. The design only allowed for a single front disc brake so a comparatively large 330 mm disc was mated to a six-piston caliper, a world first on a production bike.