How to True Disc Brake Rotor? | Silence The Rub

The procedure is simple: spin the wheel, find the high spot, bend the rotor back a fraction at a time, and recheck until it spins silent.

This guide covers the full step order, what to check before you bend anything, and the mistakes that turn a quick fix into a trip to the bike shop.

What To Check Before Truing A Rotor?

A rotor that rubs in the same spot every rotation is genuinely bent. A rotor that rubs constantly through the whole rotation usually means the caliper is off-center — bending the rotor will not fix that.

Work through this quick checklist first:

MBR notes a loose rotor can mimic a bent one, so confirm the rotor bolts are at the correct torque before you bend anything. Also make sure the caliper bolts are tight and the caliper sits centered between the pads. Let the rotor cool completely before starting — Unior’s safety guidance says hot discs and calipers should be cooled before any work.

Truing A Disc Brake Rotor: The Step Order That Works

You true a rotor by locating the wobble, bending the high spot back a little, then repeating until it clears the pads.

1. Put the bike in a work stand or flip it so the wheel you’re working on spins freely.
2. Spin the wheel and watch the rotor pass through the caliper. The spot where the gap closes is the bend.
3. Note where the deviation starts, peaks, and ends — Utah Mountain Biking recommends identifying all three before touching the rotor.
4. Rotate the bent section out of the caliper so you can work on it safely.
5. Use a rotor truing fork — Park Tool’s DT-2 is the classic choice. On the DT-2, the long slot handles small corrections and the short arm handles wider bends. Place the tool at the high spot and flex the rotor a very small amount in the opposite direction. An adjustable wrench with taped or rag-wrapped jaws works in a pinch.
6. Re-spin and watch the gap. Park Tool’s rule: if the remaining deviation is smaller than a business card, the rotor is adequately true.
7. If the rotor now rubs the opposite pad, you overbent it — bend it back gently.

Keep your fingers clear of the spinning rotor; IPMBA warns that rotor edges can cut. On two-piece rotors, bend only the outer braking surface, never the aluminum arms (Park Tool). Steel rotors spring back after bending, so expect several gentle passes rather than one big bend, per MBR. Park Tool’s rotor truing guide covers the same process step by step, including the business-card test. The same method applies to e-bike rotors as long as the wheel spins freely.

Common Mistakes And Knowing When To Replace

Most failed truing jobs come from bending too hard, bending the wrong part, or skipping the pre-checks above.

• Overbending is the most common error. Make the smallest correction you can, then recheck.
• Don’t try to fix a caliper alignment problem by bending the rotor — you’ll make it worse.
• Wrap bare metal wrench jaws in a rag or tape before using them on a rotor; exposed teeth gouge the surface.
• Never bend a two-piece rotor at the arms — the outer perimeter is the only safe place.
• If the rotor is severely bent, has been trued many times, or still won’t run true after a few careful attempts, replacement is the safest option.

When a rotor is beyond saving, our tested MTB disc brake rotor picks point you to dependable replacements.