MXA WRENCH TECH: HOW TO INSTALL AN OVERSIZED BRAKE ROTOR FOR BETTER STOPPING POWER
TIME TO COMPLETE:
|? Red Loctite
? Paper towels
? Lint-free rags
? Torque wrench
? Contact cleaner
|? New brake pads
? Tire-changing stand
? Oversized brake rotor
? Straight-blade screwdriver
? Appropriate Allen wrenches
|? Oversized brake caliper bracket
? Appropriate open-ended wrench
? Axle grease (www.maxima.com)
? Hex axle tool (www.motionpro.com)
? Appropriate socket/driver combination
With the bike clean and firmly planted on a stand, locate the front brake rotor. The easiest way to remove the stock front brake rotor is by loosening the rotor bolts while the front wheel is still on the bike. Use the appropriate Allen wrench or socket/driver combination. Do not completely remove the rotor bolts.
Take the front wheel off the bike as you normally would. Use the correct box-end wrench to remove the front axle nut (most bikes require a 22mm wrench). Loosen the front-axle pinch bolts on the fork lugs with the proper size socket/driver combination (most bikes require a 10mm socket) until the bolts are spinning freely. Remove the front axle with a hex axle tool, pulling the axle completely out of the hub and fork-lug housing while holding the wheel with your right hand. Set the axle on a clean lint-free rag. Remove the axle spacers and set them next to the axle.
Set the front wheel on a tire-changing stand (a workbench or bike stand will also suffice) with the rotor side facing up. Remove all rotor bolts with the proper wrench. Inspect each bolt, making sure that the threads are clean and the bolts haven’t been bent or broken. Clean off grime and old Loctite with contact cleaner and a lint-free rag. Remove the stock front rotor and set it in a safe, dry place for storage. Clean the hub with contact cleaner and a lint-free rag, making sure to wipe away grease and dirt that have built up on the lip of the hub.
Locate the front brake-caliper pin bolt. Depending on the model of the bike, it might be necessary to unscrew the brake-pad pin-bolt cover with a straight-blade screwdriver. Using the correct wrench, loosen the brake-pad pin bolt. Do not remove the pin (this will be done in a later step). Once this has been achieved, locate the caliper mounting bolts. Using the proper wrench, remove the two bolts that attach the caliper to the fork leg.
With your left hand, hold the front brake caliper so that the brake pads are facing up. Use the proper wrench to remove the brake-pad pin. Slide the pin out carefully, taking note of its location. Remove the left-side brake pad. The right-side brake pad will be used as a backing plate to apply equal pressure to the brake pistons (the pistons will need to be fully compressed). This can be achieved by squeezing the brake pad into the caliper with your thumbs. Note: this is important, as the pistons need to be completely compressed in order to make room for the new brake pads.
The right-side brake pad can be removed once the pistons have been completely compressed. Notice the metal brake-pad retainers and remember their location within the caliper bracket. Remove the lower retainer and inspect it for damage (replace if necessary). Clean the retainer with contact cleaner and a lint-free rag.
With the front brake-caliper bracket exposed, carefully pull the bracket away from the caliper. The bracket should slide out from the housing easily. Remove the upper brake-pad retainer from the bracket. Using the proper wrench, remove the metal bracket arm so that it can be installed on the new oversized caliper bracket. Also, remove the rubber bracket grommet so that it can be placed in the new bracket.
Apply red Loctite to the threads of the bracket arm and thread the metal arm into the oversized bracket. Tighten the bracket arm completely, and install the rubber bracket grommet into the appropriate hole. Grease the bracket arm. Place the top retaining clip into the top of the bracket housing so that the notches line up, and slide the bracket into the caliper until the bracket bottoms out.
Install the lower retaining clip into the base of the bracket. At this point, it is safe to place the new brake pads into the caliper. We recommend that you use new brake pads when installing a new oversized rotor so that the pads can properly seat with the rotor. Make sure that the brake-pad tangs are positioned properly and that the pads stay in place. clean the pad retainer pin and carefully slide it into the caliper housing and through the brake-pad pin receivers. Tighten the pin until it bottoms out. Install the brake-pad pin cover if there was one.
Remove the new oversized front brake rotor from its packaging if you haven’t already. It’s imperative that you thoroughly clean the rotor (many rotors are coated in grease from manufacturing and to prevent rusting). Spray a copious amount of contact cleaner on both sides of the rotor (or use soapy water). Use paper towels to wipe the rotor dry. With the oversized rotor completely clean and dry, position the rotor with the right side facing up (look for location marks) on top of the hub. Spin the rotor around the hub, making sure that the rotor spins freely and doesn’t rub against the hub.
Apply a dab of red Loctite to the threads of each rotor bolt. Using the proper wrench, work in a star pattern, tightening the bolts to the recommended torque setting. Wipe away any excess Loctite with a lint-free rag. Also, check the quality of your front brake fluid (unscrew the top of the front brake reservoir). If the fluid hasn’t been changed in a while or is dark, it’s a perfect time to change out the brake fluid. Old fluid or fluid that’s been subjected to humidity or drastic temperature changes will not perform like fresh fluid. Bleed the front brake.
Locate the axle spacers. Make sure that the area around the dust seals is clean. It’s best to apply grease around the lip of each axle spacer before installation. Clean the front axle with contact cleaner and a lint-free rag, and apply a thin layer of grease to the axle. Set the axle close by on a clean surface.
With the axle spacers pressed into the hub, use your right hand to guide the wheel between the fork lugs. Position the rotor into the caliper housing and between the brake pads. Guide the axle through the left-side fork lug with your left hand. Use a hex axle tool to ensure that the axle is bottomed out against the axle spacer. Thread the axle nut on and tighten with the appropriate wrench until you can see the axle rotate in the fork-lug housing. Pump the front brake and spin the front wheel. Spike the brake lever several times and have a friend hold it on while you tighten the front pinch bolts. Use the appropriate socket with a torque wrench to tighten the pinch bolts to the proper setting. Tighten the axle nut to the proper torque setting as well.
Clean the caliper bolts and inspect them for any damage (replace, if necessary). Apply blue Loctite to the bolt threads. Make sure to mount the caliper outside of the left fork-lug mounts. Tighten the caliper bolts to the recommended torque setting found in your owner’s manual. Lastly, make sure to break-in the rotor and brake pads by slamming the front brake lever a dozen times while riding moderately fast in an open area. Let the brakes cool, and then follow the same procedure one final time in order to fully break in the rotor/pads.