Article about brakes and temperature

[Motofool]

This article describes what happens in brakes at microscopic level and how temperature affects it.

Caveat: the article is directed to cars' brakes, which discs are more rigid and with internal ventilation and made of cast iron.
Motorcycle's discs are made of steel and are less rigid and less ventilated, so they do warp.

The "Warped" Brake Disc and Other Myths of the Braking System

The important fact to remember is that our brakes are the mechanism that transforms the speed (kinetic energy) of our bikes into heat, which goes away into the atmosphere.

Cool or equally heated discs are happy.
The fastest and stronger the deceleration is, the most heat goes through pads and discs.

If we can avoid those decelerations, using more time to slowing down, we are avoiding glazing, warping and fluid and parts ware; what what is more important: our brakes will be in top shape in that emergency situation, when we need them most.

[alex.s]

Nice.


"In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures."

very interesting.

"break-in... ten increasingly hard stops from 60mph to 5 mph with normal acceleration in between should get the job done for a high performance street pad. During pad or disc break-in, do not come to a complete stop, so plan where and when you do this procedure with care and concern for yourself and the safety of others. If you come to a complete stop before the break-in process is completed ... Game over."

"For a race pad, typically four 80mph to 5 and two 100mph to 5, ... to raise the system temperatures ... hence,... material can establish its layer completely and uniformly on the disc surface. ... new discs should be bedded with used pads of the same compound that will be used going forward."

"Other than proper break in, as mentioned above, never leave your foot on the brake pedal after you have used the brakes hard."

i've always told people that this is what warps rotors. i'm glad i'm not bullshitting