MTB cranksets and cranks

How to choose your MTB crankset

The single chainring has simplified the choice, but not compatibility: the spindle, chainline and crank length determine the setup. Shimano, SRAM, Race Face and e*thirteen cover everything from entry-level to carbon.

Which spindle standard?

This is the point where most installations fail: the crankset spindle must match your frame's bottom bracket.

• Shimano Hollowtech II : 24 mm spindle, the most common.
• SRAM DUB : 28.99 mm spindle, specific to the brand.
• Race Face Cinch and equivalents : 30 mm spindle.
• The same spindle standard can be fitted to different BSA or Press Fit bottom brackets using suitable spacers.

Which chainline?

• Boost (52 mm) : the standard on almost all recent MTBs.
• Super Boost (56 mm) : found on some frames with high tyre clearance.
• Non-Boost (49 mm) : older frames.
• An incorrect chainline wears the drivetrain and impairs shifting on the outermost sprockets.

What crank length?

• 165 to 175 mm, with a clear trend towards 165 and 170 mm in MTB.
• A shorter crank arm improves ground clearance and reduces pedal strikes on descents.
• Changing crank length alters your saddle height: adjust it accordingly.

Complete crankset or crank arms only?

On systems with a removable chainring (Direct Mount, Cinch), crank arms alone are sufficient if you keep your chainring. A complete crankset remains simpler when you are also changing the tooth count or chainline.

To find out more: How to choose your MTB crankset

See also: MTB chainrings · Bottom brackets · Drivetrain parts and accessories