By brian fiske
Help your brakes work better and last longer by avoiding these common errors
The bad news about road bike disc brakes? There isn’t any, no rx really, as long as you avoid these five common mistakes that apply to any bike’s disc brake, shared by Nate Newton, a technical rep for SRAM.
1. Touching the rotor’s brake surface. Two problems here. One, rotors can get really, really hot after braking—so touching one after a descent or at the end of a ride could be unpleasant. Two (and most important), oils from your fingers can contaminate the rotor and cause a loss of brake power (and make the brakes noisy, too). Which is very much like…
2. Accidentally getting lube, degreaser, or brake fluid on the rotor or pads. This is even more certain to cause a brake power issue than the oils from your skin. If you do accidentally splash some lube or other fluid on the rotor, remove the wheel from the bike and clean the rotor thoroughly with isopropyl alcohol and a clean rag. If you get any on the brake pads, it’s best to replace them. You might be able to save them by sanding off the top layer of pad material, but often the oil or fluid with seep into the material and then continually contaminate the rotor, which will impact braking.
3. Squeezing the brake lever with the wheel off the bike. If you do this with hydraulic brakes without a pad separator between the pads, they’ll push in until they contact each other and then won’t retract enough to get the rotor back in place. Fortunately, the fix is easy: Wiggling the pad separator in place can re-set the pads. If the separator doesn’t fit, remove the pads and use something thin and flat (like a flathead screwdriver) to carefully push the pistons back into the body of the brake. Reinstall the pads and the wheel, squeeze the brake lever a few times, and you’re good to go.
4. Forgetting to check brake pad thickness. Disc brakes are low maintenance, but the pads do wear out. Once the brake-surface material is thinner than about 2.5mm (roughly the width of two dimes), replace the pads. Swap out rotors when the width hits 1.5mm.
5. Using the wrong tools or fluid. Using mineral oil in a brake meant for DOT brake fluid (or vice versa) is a recipe for failure. So is not using a torque wrench to tighten fasteners. And using your fingers to straighten a warped rotor? Well, we already covered that. So, your rules of thumb: If you plan on maintaining your brakes yourself, know which type of brake fluid to use; always use a torque wrench; and use a tool—not your fingers—to true a rotor.
Why Ride Disc Brakes on Road Bikes?