When do I need to replace a bike brake rotor?

Replace your rotor when it's worn below the manufacturer's minimum thickness, has deep grooves or scoring, or is heavily discolored. A warped rotor that can't be trued is also a clear sign it needs to go. The minimum thickness is stamped directly on most rotors.

Do I need to replace my brake pads when replacing the rotor?

Not always, but often it makes sense. Pads and rotors bed in together over time. Pairing a new rotor with worn pads can cause reduced initial braking performance or noise. If the pads are heavily worn or glazed, replace them at the same time.

Can I fit a larger rotor?

Only if your frame, fork, and brake caliper are approved for the larger size – and you have the correct caliper adapter. If you're unsure, stick with the current size or check the manufacturer's specifications. Common rotor sizes are 140, 160, 180, and 203 mm.

Why do I need to bed in new brake rotors?

Bedding in allows the pad and rotor to conform to each other properly, which is what unlocks full braking performance. Without it, braking can feel weaker than expected, uneven, or noisy.

ADVICE / REPAIR & MAINTENANCE

How to replace a bike brake rotor

Change your brake rotor in three simple steps.

> Jump to tools and materials
> Jump to step-by-step guide

Worn down or due for an upgrade? This guide shows you how to swap your brake rotor in just 3 steps – for Centerlock and 6-bolt mounting systems.

What you'll learn

Jump to the step you need and get your brakes back in shape:

WHAT YOU'LL NEED

Tools and materials

For Centerlock rotors:

Hollowtech II bottom bracket tool (external spline) or cassette lockring tool (internal spline)

For 6-bolt rotors:

T25 Torx or matching hex key
Thread locker (if reusing old bolts)

General:

New brake rotor (Centerlock or 6-bolt)
Shop rag and brake cleaner

Optional: Torque wrench, calipers for wear measurement

Ready? Let's get started.

Wera

950/9 Hex-Plus Multicolour HF 1 - L-key Set with holding function - 9 Pcs.

BLUECHAIN

Bottom Bracket Wrench for Shimano Hollowtech II with Mounting Tool

Shimano

TL-FC36 Bottom Bracket Wrench for Hollowtech II BB Cups

Topeak

YTORX Speed Wrench T10 / T25 / T30 Torque Key Set 3 Pieces

STEP 1a

Remove the old rotor (Centerlock)

Remove the wheel from the bike. Place it rotor-side up on a workbench or on the floor. Seat your Centerlock tool – either the external spline (Hollowtech II bottom bracket tool) or internal spline (cassette lockring tool), depending on your rotor. Turn the lockring counterclockwise to loosen it, then remove it and lift the rotor off the hub.

Pro tip: Before fitting the new rotor, clean the Centerlock interface and hub flanges with brake cleaner.

STEP 1b

Remove the old rotor (6-bolt)

Place the wheel rotor-side up on a workbench or on the floor. Seat the Torx or hex key straight and as deep as possible into the bolt head before loosening the first bolt – this reduces the risk of slipping and damaging the bolt head. Loosen all six bolts counterclockwise, then lift the rotor off the mounting interface.

Pro tip: Before fitting the new rotor, clean the mounting interface and hub flanges with brake cleaner.

STEP 2a

Install the new rotor (Centerlock)

Place the new rotor onto the Centerlock interface with the label and directional arrow facing up. Thread the lockring on by hand clockwise first – this confirms the threads are engaging cleanly. Stand the wheel upright, seat your Centerlock tool, and tighten the lockring. Use a torque wrench to hit the manufacturer's specified torque – on most Centerlock systems, that's 40 Nm.

STEP 2b

Install the new rotor (6-bolt)

Check whether your bolts already have thread locker applied – look for a colored coating on the threads. If not, apply medium-strength thread locker and let it tack up before proceeding. Place the new rotor onto the mounting interface with the label and directional arrow (if present) facing up. Insert the first bolt (with a locking washer on Shimano systems) and thread it in finger-tight. Thread in the remaining bolts finger-tight. Then torque all six bolts to approximately 4–5 Nm using a torque wrench, working in a star pattern.

STEP 3

Reattach the wheel and bed in the brakes

Wipe the new rotor down with brake cleaner after installation. If the brake caliper pistons are too extended for the new rotor, push them back with a flat tire lever before reinstalling the wheel. Reinstall the wheel, then bed in your disc brake. This brings the brake up to full stopping power.