Proper Disc Brake Wear-In

January 16, 2009 by Scott Mosko
Filed under Tips

Disc brakes are one of the best advancements in mountain biking, especially downhill bikes. Rims can get bent without affecting the braking surface, braking power is much better, and water and mud are much less of an issue. However, disc brakes require more attention to the break-in period than V-brakes.

Recently, I set up a new personal bike of mine with Avid Juicy Ultimate brakes — 160mm rotors on the front and 140mm rotors on the rear. Although those brake are made to be extremely light and they are not extremely aggressive, I felt that they would be more than adequate for my 29” rigid single speed. There were some mounting issues with the rear brake due to the frame design, so I was down to the wire getting the bike ready for the ride the next day. After the first downhill, I realized that I had made an error in my haste – I had never broken in the brake pads. By the end of the ride, the brakes were fine, and a perfect match for that bike after they had worn in. However, the process could have been sped up with a few minutes of prep work.

To break in the pads, you want to slow the bike down from gradually increasing speeds. However, it is important not to come to a full stop. Basically, the best way is to find a gradual incline where you can make several runs with increasing speeds. Start at roughly 5mph, and slow the bike down to 1-2mph. Again, it is important not to lock the brakes up by stopping. Gradually increase the speed with the next run by roughly 3mph – 8mph on the second run, 11mph, etc. It is as simple as that. The main purpose is to seat the pads to the rotors, and also burn off any initial residue from the rotor or pads. After a total of 4-5 runs, the brakes should ready for actual riding on the trails.