19/07/2017 2:38pm
Brake pads may well appear to be uncomplicated but they are effectively the result of a very complicated and sophisticated technology. They must have characteristics that are not easy to obtain. They need to have a very high friction coefficient and it must only change minimally with temperature variations in order to ensure consistent levels of braking torque. It must also continue to do this as time passes and as the pad material wears and reduces. Then we can also throw in a few other factors like rain, mud, freezing temperatures or heat waves. All in all a pretty challenging set of criteria.
There are essentially two types of brake pads available on the market. Organic and Sintered. Organic pads contain more metallic fibres (principally aluminium and brass), Kevlar fibres, carbon and the resins used to bind them. Sintered pads contain metallic powders mixed with lubricants and abrasive agents. The metal powders determine the braking power of the pad at high temperatures, the lubricants help to stabilise the overall braking action and the abrasives keep the discs clean. They tend to be more expensive but also ensure greatly improved performance. They contain mixtures of metallic powders, normally containing a high percentage of copper and are sinterised at very high temperature and pressure. These materials are highly conductive and therefore pass more heat through to the calipers and brake fluid. However, their use has resolved many problems and today performance in both wet and dry conditions is excellent. Also almost all the development going on in motorcycle brake pads currently is in sintered technology.