UPDATE: THIS IS NOW 5 REASONS TO HAVE BIGGER ROTORS!!
[VIDEO ADDED BELOW]
Now that we have learned more about braking with BrakeAce, there are a number of things we can do to improve the performance of our brakes.
One of the best things we can do to get better performance from our brakes is to have larger rotors.
The reason for this is that every time we use our brakes, we are removing energy from the combined kinetic energy of ourselves, our bike and our speed.
This energy is transformed *mostly* to heat, which builds up in our rotors and pads. Too much heat and we lose performance of our brakes, since beyond a certain point, the coefficient of friction between the pads and rotors will reduce. Beyond this, we get a boiling of the pad material or even brake fluid. These are obviously not ideal!
Larger rotors have a greater mass and allow for greater storage of heat. This is good because if there is a greater capacity for heat in the rotors, your brake pads and hose fluid can stay at operation temperatures.
Furthermore, the larger rotors have a greater area, which means that heat can also dissipate more quickly.
See below for now FIVE reasons to try larger diameter rotors.
That old BrakeAce brake power meter prototype was huge…but very useful!
Below are 5 Science-Based reasons you might want to consider bigger rotors:
REASON #1 TO HAVE BIGGER ROTORS
Very fast riders have greater kinetic energy than slow riders. In fact, greater speed increases your kinetic energy more than what your weight does!
Kinetic energy= 1/2*mass*velocity^2
To remove the kinetic energy, we use the brakes, and this is measurable as brake energy. This means that for the fast riders to slow down as much as we do, they will need to remove more energy (and thus build more heat!).
Having a larger area for the heat to be transferred means that less heat builds up on the braking surface itself, thus saving our pads and keeping the temperature of our brake oil within an operational range (i.e. less brake fade).
If fast riders want to ensure the performance of their brakes, they might want to look at larger rotors. 203mm is really the only option for enduro and DH racers.
Lately there has been more and more interest in even BIGGER rotors. Here are some Galfer rotors on test with the BrakeAce in 223 and 246 on this Giant Reign 29er, and then a 246mm rotor on the front of a Giant Trance 29er.
They work amazingly!
Galfer 246mm rotor with BrakeAce