Brake Clearance Template Checker

This checker works by comparing the brake caliper's outer radius with the wheel maker's clearance template. Many wheel makers publish a template or an "X-factor" curve for this check.

1. Measure the caliper's outer radius from the hub center, for example 175 mm (6.89 in).
2. Enter the rotor diameter, for example 355 mm (13.98 in).
3. Enter the wheel's template radius at the same position, for example 182 mm.
4. Read the clearance: 7 mm.

The formula is Clearance = Wheel Template Radius − Caliper Outer Radius.

Worked example: a 172 mm template radius against a 168 mm caliper radius leaves 4 mm, which passes a 3 mm minimum.

The conversion table converts 10 rotor diameters from 280 mm to 420 mm into inches and radius. The rotor radius is the starting point for estimating caliper position.

The note under the table repeats the main rule: the caliper, not the rotor, decides whether the wheel clears.

The Brake Clearance Template Checker is a tool that checks whether a wheel's inner barrel and spokes clear the brake caliper. Brake upgrades and minus-size winter wheels both risk caliper contact.

Wheel makers publish clearance templates, and wheel diameter alone does not predict clearance. Spoke shape and barrel thickness change clearance by several millimeters between wheels of the same size.

This checker has 4 uses: big-brake upgrades, winter wheels, spoke checks and wheel shopping.

• Plan big-brake upgrades: Check new calipers against current wheels.
• Plan winter wheels: Confirm smaller wheels clear the brakes.
• Check spoke clearance: Compare spoke depth with caliper face.
• Shop for wheels: Filter wheels by brake clearance.