Ankle Angle at BDC
Target≈90°–110° (slight plantarflexion)
included knee–ankle–toe angle with the crank at bottom-dead-centre (6 o'clock).
Why this matters
Ankling — how the foot rotates through the stroke — affects how smoothly force crosses the bottom of the stroke. A persistent toe-down "pointing" at BDC overloads the calf and Achilles and can leak power.
What good looks like
At BDC the ankle sits roughly neutral to slightly plantarflexed, with the ball of the foot driving the pedal and the heel only marginally higher.
Common faults
- Toe-down (> 110°) — calf-dominant pedalling; loads the Achilles, often pairs with a rearward cleat fix.
- Heel-down (< 90°) — can accompany a slightly high saddle.
Coaching cues
- If the rider points the toe through BDC, try moving the cleat rearward and re-check.
- Read alongside knee extension at BDC — ankling and saddle height interact.
How to draw
- Pause at bottom-dead-centre on the measured leg.
- Shank line: knee → ankle (lateral malleolus).
- Foot line: ankle → ball of foot / pedal.
Related measurements
- Knee Extension at BDC — same frame, the leg side.
General bike-fit guidance, not a clinical recommendation.
source · sports/cycling/learn/cycling_ankle_angle.md