Road brake rotors

How to choose your road disc brake rotor

A warped, excessively worn or overheated rotor immediately impairs braking. Shimano, SRAM, Galfer, Clarks and BBB cover both mounting standards and heat-dissipation technologies.

Centre Lock or 6-bolt?

• Centre Lock : the rotor slides onto the hub splines and is secured with a lockring; a quick-fitting system and the dominant road standard.
• 6-bolt : the rotor is secured with six Torx bolts.
• It is the hub that determines the standard. Adapters are available from Centre Lock to 6-bolt, but not always the other way round.

Which diameter?

• 140 mm : often at the rear, on lightweight bikes and for smaller riders.
• 160 mm : the most common standard, front and rear.
• Moving from 140 to 160 mm increases power but requires a caliper adapter corresponding.
• Observe the maximum diameter accepted by your fork and frame.

When should it be replaced?

• Theminimum thickness is engraved on the rotor, usually 1.5 mm: below this, replacement is mandatory.
• A warped rotor causes intermittent rubbing and a regular noise with every wheel revolution.
• Replace the pads at the same time, and bed in the assembly before riding fast.

See also: Road brake pads · Complete road brakes · Brake tools