The right brake pad for all motorbikes and all riders
The working temperature of braking system is the decisive element when it comes to choosing the right pad, whether it’s made of sintered or organic materials.
The performance levels of the brake pads, characterised by highly differing mixtures, are described with the aid of 2 main parameters: efficiency and wear.
Efficiency (i.e. how well the pad brakes): expressed via the average friction coefficient, and the friction stability in the face of the main features of the braking operation (speed, deceleration, temperature).
It is measured by means of specific bench tests and tests carried out directly on the vehicle. Wear, on the other hand, is expressed as the amount of worn friction material in relation to the number of braking operations made.
The operating differences between the various mixtures are highlighted in relation to the variation in the friction coefficient with different working temperatures: the Racing mixtures have a very high hot friction coefficient (where a working temperature of 350-450°C is normal), whereas the street mixtures are designed to work best at medium/low temperatures (below 300°C).
Consequently the latter will suffer a “fading” effect (i.e. a deterioration of the friction coefficient) if used on the track and hence over-stressed.
In fact, they tend to be less efficient when used above a certain temperature. And the use of racing mixtures on the road (with cold discs) will produce a less effective grip and a longer braking stroke.
As you would expect, the intermediate mixtures are a compromise between these two situations. They offer good performance in all normal conditions, but they don’t excel at the two extremes of the working temperature range.
Brake pads made of sintered materials consist of metallic powders with the addition of lubricants and abrasives combined via a process using pressure and high temperatures.
During the sintering process, the compound attaches itself to the metallic support (of the required shape) without the need for any type of adhesive.
The metallic powders determine the braking capacity of the pad and its stability at high temperatures; the lubricants increase the overall stability of the braking operation, while the abrasives keep the discs clean.
Brake pads made of organic materials consist mainly of binding resins, metals, lubricants and abrasives.
In this case, the friction coefficient is generated by the metals and resins while the lubricants increase the overall stability of the braking operation and the abrasives keep the discs clean.