MotoGP has been absolutely wild this year, but if you’d rather learn a thing or two about MotoGP braking systems and how they work a little differently than the braking system on your motorcycle or mine, you should watch (or at least listen to) this video my MotoGP’s Simon Crafar. In the video Simon discusses everything about motorcycle braking, from the cutting edge of the industry’s technology.
Why MotoGP motorcycles don’t use steel brake rotors
MotoGP motorcycles don’t use steel brake rotors, even though steel stops very very well. The problem is that once steel reaches 600-700 degrees Celsius, the brakes lose braking force friction. This means braking is less consistent between when the brakes are cool and when the brakes are hot from use.
Another disadvantage to steel brake rotors is that steel expands when it reaches high temperatures. Motorcycle racers can actually feel the disk expanding while they’re riding, because the brake lever will start pushing back outwards or upwards.
Why MotoGP motorcycles use carbon brakes instead
The immediately obvious advantage when you pick up a carbon brake rotor versus a steel one is how much lighter the carbon disk weighs. Shaving weight off a motorcycle always leads to better power-to-weight ratio, but that’s not all. The real advantage for motorcycle racing is that a faster spinning disk brake creates less gyroscopic effect: if a rider enters a chicane (an s-curve), he or she can more easily bring a bike from leaned to the right to over to the left and vice-versa with carbon rotors than with steel ones.
Another advantage of carbon brakes are that they don’t expand like steel brake rotors do. In fact, carbon brakes can actually go up to roughly 1,000 degrees Celsius a few times a lap for a short time before they start to burn. Less issues with heat and expansion leads to better consistency in brake performance, which means more safety and more predictability for the riders to take advantage of.
What’s a disadvantage of carbon brakes?
Carbon brake rotors have one major disadvantage (aside from the price), and that is, they function best when warmed up. In the video Simon explains that motorcycle riders will ride through pit lane dragging their brakes before a race. That’s because carbon brakes don’t really work as well as racers would like until they reach about 250 degrees Celsius. This is one reason why we don’t see street motorcycles equipped with carbon brakes.
What are high-mass disks?
High-mass disk brakes are used a few times a year in MotoGP at specific race tracks with extreme braking, such as the Motegi, Japanese track. Essentially the sidewall of the rotor is taller than the regular sized carbon disk brake. High-mass disks are designed to make the heat leave the part of the rotor that the brake pads touches and make it run away to help keep the temperature lower.
How are MotoGP brake line hoses different than regular street bike brake hoses?
MotoGP brake lines may look like rubber brake lines from the outside, but they’re actually made with steel wire. Because of the strength of the steel wire, the hoses don’t expand, which means better brake response, no delay between when a rider pushes the brake lever and the brakes coming on, and no push-back from the brake lever. The differences might be measured in fractions of a second, but that makes a world of difference in racing.
How are MotoGP brake calipers different than regular street bike brake calipers?
Before watching this video, I never knew how cool MotoGP brake calipers look! Brakes generate so much heat from friction, which can transfer from the brakes, through the brake lines, to the calipers, so to help disappate some of that heat, Brembo’s engineers have created what looks like the lovechild of traditional brake calipers and an air cooled engine. The result is brake caliper with cooling fins to help remove some of the excess heat from the braking system.
Admittedly, I wasn’t the biggest fan of Simon Crafar’s interviews with racers and staff on the paddock before and after MotoGP races, but in this video we get to see Simon’s passion for racing really shine. You can tell he has a ton of knowledge and insight, both from his own days as a racer as well as staying an active part of the MotoGP community.
If you’re interested in learning about braking systems in MotoGP bikes you should definitely give the video a go, as it covers what I’ve shared here but in a bit more detail. When you’re done, maybe watch this video on how to bleed your own brake lines: