Disc Brake Rotors for EMTB & MTB Bikes

If the brake pads are the hands, the rotors are the spinning discs they grab to bring everything to a halt. Rotors are essentially big heat sinks—their job is to turn your speed into heat and then get rid of that heat as fast as possible so your brakes don't "fade" or lose power on long descents. For MTB and eMTB riders, size really does matter here; a larger rotor provides more leverage and a bigger surface area to stay cool, which is why you’ll often see massive 200mm or 220mm discs on the front of heavy-duty bikes.