How to Change the Rotors on Disk Brakes




About: Second year engineering student studying at the Beautiful Okanagan campus of The University of British Columbia. I like to tinker with electronics and meddeling with 3D printing. I also have a penchant for r...

My bike was recently tuned however it developed an irritating screech and lack of braking power, so we decided to change the disks and fix the problem. Changing the disks is vary easy all it requires is a torks T25 screwdriver, and preferably a torque wrench. If you don't have a torque wrench don't worry unless you are racing, screw tight will do. 

Step 1: Tools and Materials

This is an easy project that takes about 30min the only tools needed are:
torque t25 screwdriver 
torque wrench (optional) needs to go to 40-60in lbs

new disk 

Step 2: Take Off Tire

Undo quick release (if you have one), and remove tire from bike. Same goes with rear tire, its best if you are in you're highest set of gears. 

Step 3: Change Disks

Any torque screwdriver will do to undo the screws. Undo the screws in pairs, first top right then bottom left exc..
Once the disk is off place the new one in place and first hand tighten all screws in the same pattern.  Then if you have a torque wrench correctly set it to 40-60in lbs. To set the wrench start by un doing the wrench completely and then screwing the handle up to somewhere between 40-60 in lbs (not ft lbs). If you don't have a torque wrench (or it can't go to 60 in lbs) do your best to tighten all the screws evenly. Once all the screws are done up the wheel can be placed back on the fork and the quick release can be tightened. Then take the bike for a test run and make sure the brakes are working, trust me finding out at the top of the hill is  much worse. 

Sorry about the super wide angle pictures.

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    6 Discussions

    Hey Zaphod - thanks for th ewriteup - I thought this was more involved! Do the rotors come in different sizes, or do I need to worry about matching the new rotor to existing?

    1 reply

    Yes rotors do come in different sizes, they are measured in mm most are 160 with smaller and bigger sizes available. I would just use a ruler and measure the ones you have. also some of the bolt patterns (5 or 6) are different. of you take the one on your bike of and bring it to a bike shop you should be able to get a good match. is a great way to order online, great customer service


    6 years ago on Step 3

    Great Instructable! This doesn't happen very often but if your brakes rub when wheel is spinning, loosen the brake callipers at the frame, spin the wheel, pull brake on, and keeping the brake held in, tighten the screws. This normally requires a 5mm allen key. Keep up the good work :)

    1 reply

    6 years ago on Introduction

    Did you try changing the brake pads or cleaning the rotor before you swapped out the rotor? That could have been your problem.

    1 reply

    Had new pads, used automotive brake cleaner too. Taken it to a mechanic, he couldn't figure out the noise either. We have contacted shimmano to resolve the problem.