The disc brakes on your motorcycle are built to provide better performance than any other type of brake. Disc brakes are comprised of the brake pads, calipers and rotor. The brake caliper houses the brake pads, which squeeze the rotor when you apply pressure to the brake lever. The system is controlled by hydraulic fluid instead of cables so as to reduce the frequency of adjustments, but even so, every once in a while they may go out of adjustment and the brake pads may rub the rotor on the wheel constantly.
Set your bike on a flat, level surface and put down the centre stand if you have one. If not, the side stand will work fine to perform this procedure, just be careful not to knock the bike on the opposite side of the stand while you are working.
Examine the front wheel and brake set-up. Most front brake calipers are out in the open, so you can get to them easily. On some bikes, however, you may need to remove a cover in order to work. Refer to your owner's manual if you are unsure, then remove any parts necessary to gain full access to the brake set-up.
Locate the two mounting bolts that hold the brake caliper onto the front fork. Remove these bolts using a socket and wrench, or hex wrench depending on your model motorcycle, and pull the brake caliper away from the rotor and front wheel. Use a tire lever or similar strong and slender object to push the brake pads toward the outside of the caliper. This will force brake fluid back into the main reservoir, essentially resetting the brake pad alignment.
Set the brake caliper back in place and reattach the mounting bolts you removed previously. Do not tighten them fully. Only tighten them enough to hold the caliper in place. Squeeze the front brake lever multiple times. If will feel soft at first, and will slowly regain its usual firm pull. Use a zip tie to secure the brake lever in the closed position.
Return to the front brake and tighten the front brake caliper bolts securely using a socket and wrench or hex wrench. Because you have the brake lever held shut, the brake caliper should not move or swivel as you tighten the mounting bolts. When you are finished, cut the zip tie on the brake lever and take your bike out for a ride. The brake should now be perfectly aligned and should not rub on the wheel while riding with the brake lever in the open position.
- "Motorcycle Basics Haynes Techbook"; John Haynes; 2002