Crank length: the component almost nobody checks (and should)

Crank length defines the diameter of the circle your feet draw. Most cyclists have never checked theirs — they ride whatever came on the bike, sized to the frame, not to their legs.

Find yours in 10 seconds

Look at the inner face of the crank arm, near the pedal axle: the length is engraved — typically 165, 170, 172.5 or 175 mm.

Starting range by inseam

• Inseam up to ~76 cm: 165 mm
• Inseam ~76–81 cm: 170 mm
• Inseam ~81–86 cm: 172.5 mm
• Inseam above ~86 cm: 175 mm

That's the reference table FitRide uses as a starting point. It isn't dogma — it's the centre of the sensible range for your leg length.

When shorter makes a real difference

Cranks that are too long close the hip and knee angles at the top of the stroke (12 o'clock). The signs: pinching at the front of the hip, knees striking the chest in an aero position, difficulty spinning high cadence. Going 5 mm shorter opens the top of the stroke with no practical power loss — the smaller lever is compensated with cadence.

Changed cranks? Re-set your saddle height: an arm 5 mm shorter calls for a saddle ~5 mm higher to keep the same extension at the bottom of the stroke.