Spin Doctor Tech Tip – Breaking In Disc Brakes
March 23, 2010 54 Comments
You just got new disc brakes or new pads for your old disc brakes. But now that you’ve started riding, the brakes don’t stop like they used to. What do you do?
Well, you need to start by breaking in your new disc brakes, or, as the process is sometimes called, burnishing, burning in or bedding in. Whatever you call it, it will make your disc brakes work better by doing 3 things:
1) It will rid the pads and rotor of superficial oil, grime and contaminants that inhibit friction.
2) It will reshape the pads so that they conform more accurately to the rotors. After breaking in more of the pads will contact more of the rotor.
3) It will increase stickiness (coefficient of friction) of the system by transferring a thin, even layer of brake pad compound to the rotor.
Okay, that’s easy to say but how do you do it? Let’s ask the brake experts:
The bed-in procedure, which should be performed prior to your first ride, ensures the most consistent and powerful braking feel along with the quietest braking in most riding conditions.
To safely achieve optimal results, remain seated on the bike during the entire bed-in procedure.
1) Accelerate the bike to a moderate speed (approximately 19kmh or 12mph), then firmly apply the brakes until you are at walking speed. Repeat approximately 20 times.
2) Accelerate the bike to a faster speed (approximately 32kmh or 20mph). Then firmly and suddenly apply the brakes until you are walking speed. Repeat approximately 10 times.
3) Allow the brakes to cool prior to any additional riding.
Rotors need to be burned in and pads need to be burnished. When replacing either, or on a new bike, follow the steps below to get the most out of your brakes.
• Remember that any time a rotor is replaced the pads should be replaced as well. So if you are burning in a rotor you are also burnishing the pads.
• Burning in a rotor refers to transferring a little of the pad compound into the surface of the rotor. This helps the pad grip the rotor.
• Burnishing pads refers to polishing the surface of the pads so that they have more grip on the rotor.
• It takes about 20 stops for the burn in to take place. It is important to do this in controlled and clean conditions.
• Preferably on pavement, get the bike up to a good speed and then firmly and evenly apply the brakes until the bike comes to almost a complete stop. Repeat this process 10 to 20 times.
• If the bike is ridden hard before the burn in process is performed the rotor can be ruined. Indications that this has happened are noise and lack of power.
It takes 20-30 hard stops to burnish the brake pads.
Before riding check the correct action of the brake and that braking effort is applied as the lever is pulled. To achieve the maximum braking effort the new brake pads need bedding in. Bed in the pads by riding a short distance with the brake applied, it also helps to pour clean water over the caliper and pads whilst bedding in. This procedure will achieve good braking performance but will reach its full potential after a few rides.
So always remember to break in your new disc brakes or pads, and you’ll be ready to hit the trails and stop on a dime!