What advantages do I get with a bigger rotor? What should I choose?
As big as possible, as small as necessary!
In general, most bikers will benefit from larger rotors. This is because the same amount of hand pressure with a 203 mm rotor will produce around 10 % more braking power than with a 180 mm rotor. A 220 mm rotor will produce around 20% more braking power. A larger diameter rotor reduces the force required to produce the same amount of braking power, prevents brake fading and provides more security. Large rotors are a must for heavier riders. Always consider the total weight of the rider, bike, and backpack/luggage. A fully loaded backpack can increase the demands on the braking system.
But keep in mind: Bigger is not always better. You will only reach the sweet spot of performance, if you’re able to bring your pads and rotors up to temperature. Too big of a rotor combined with too low demands on the system or lower rider weights will lead to an underchallenged system. It will also decrease your ability to properly feather the braking power. The brake will act more abruptly, the wheel will lock up more often, leading to a decrease in controllability.
Furthermore, larger rotors combined with lower rider weights generally extend the break-in period required for the pads and rotors to develop full power. It can even be impossible for riders weighing under 70 kg to effectively bed in their brake pads with a rotor diameter larger than 180 mm, due to the pads and rotors not reaching the necessary temperatures. A lack of braking power or increased noise levels are often caused by brake pads that have not been fully bed in and/or by set-ups that don’t reach the necessary temperatures during use for the pads to be “cleaned” regularly. Pads and rotors that have not been properly bed in won’t reach their optimal performance and wear will increase. FAQ: Bedding-in Procedure
If you have any questions regarding optimal setup, please contact your magura dealer, our event team or our social media chat.