Repair guides › Brakes
Center and adjust a road caliper
A caliper that bolts through the fork crown or rear brake bridge and reaches around the tire to squeeze pads on the rim. Standard on road bikes before discs. Two arms on two pivots pull together when the cable tightens. A quick-release lever on the caliper opens it to remove the wheel, a barrel adjuster sets cable tension, and a small screw on top centers it. Pads are usually cartridges: a metal holder with a slide-in insert.
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Tools
- Ball-end hex key set (1.5–10 mm): Park Tool HXS-1.2 Professional L-Shaped Hex Set ($$)
- 1/4" click torque wrench (about 2–17 Nm) + bits: Pro Bike Tool 1/4 inch drive click torque wrench set (2.2–16.9 Nm) ($$)
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Steps
- Close the caliper's quick-release lever.
- Turn the centering screw on top (2–3 mm hex) until both pads sit the same distance from the rim. Older calipers without one: loosen the mounting nut, center it by hand, retighten to 8–10 Nm.
- Set pad height and toe-in (see Replace rim brake pads).
- Set cable tension with the barrel adjuster so the pads sit 1–2 mm from the rim and the lever stops well before the bar.
Torque
| Fastener | Torque |
|---|---|
| Caliper mounting nut | 8–10 Nm |
| Cable anchor bolt | 6–8 Nm |
Diagram
Seen from the front of the bikeFront brake
Signs it needs doing
- One pad rubs (off center)
- Squeal (glazed pads or no toe-in)
- Lever comes close to the bar (pads worn or cable stretched)
- Weak in the wet (normal for rim brakes: use salmon-colored pads)