Gravel cranksets and crank arms

How to choose your gravel crankset

Two things distinguish a gravel crankset: its smaller chainrings than on a road bike, and a wider chainline to clear tyres of 45 mm and wider. The other consideration is the spindle, which must match the frame’s bottom bracket.

Single or double

• The single chainring is chosen by tooth count — usually 38 to 44 — to suit the cassette. Go smaller for trails and loaded riding, or larger for speed.
• The gravel double offers lower gearing than a compact road crankset. Shimano’s GRX RX810 with 48/31 chainrings and RX600 sub-compact with 46/30 chainrings cover the main options.
• Many cranksets are available in both versions : you can change the chainring, but not always the chainline.

Chainline and Wide versions

SRAM cranksets Wide move the chainrings outwards by 2.5 mm to clear the chainstay and accommodate wider tyres. This makes it possible to run a 2x gravel bike with large tyres. In return, a Wide double crankset requires a Wide front derailleur. Shimano GRX also has a wider chainline than a road setup.

The spindle determines compatibility

• SRAM DUB (28.99 mm): the current SRAM standard.
• Shimano Hollowtech II (24 mm): GRX and CUES.
• BB30, GXP and BB386 : older standards still available in the range.
• Praxis M30 (30 mm): specific to the brand.
• Each spindle requires the bottom bracket that matches the frame’s standard. Several models are sold without a bottom bracket : check this when ordering.

Crankset or crank arms only

The crank arms are sold without a chainring, particularly SRAM models with Direct Mount : you then choose the chainring, tooth count and, where applicable, the power-meter chainring. It’s the most flexible way to build a custom 1x drivetrain.

Crank arm length

Usually 165 to 175 mm. On a gravel bike, slightly shorter crank arms lift the pedals further from the ground and reduce pedal strikes in ruts — an advantage you don’t get on the road.

To find out more: How to choose a road bike crankset

See also: Gravel chainrings · Bottom brackets · Power meters