Form fundamentals
Saddle Height
Your knee extension angle at the bottom of the stroke — the single most important fit measurement.
What good looks like
What it is
Saddle height is read from your knee extension angle at the bottom of the stroke (6 o'clock) — how far your knee is from fully straight (0° = locked out). Too straight (small angle) and the hips rock; too bent (large angle) and the knee stays crunched, robbing power and stressing the front of the knee.
Why it matters
Saddle height drives nearly every other fit number and is the leading cause of cycling knee pain. Get it right first — anterior knee pain usually means too low (over-bent), posterior knee pain and hip rock usually mean too high (over-straight).
How we detect it
We track your near-side ankle to find the bottom of each pedal stroke, measure the hip-knee-ankle angle there, and report the extension angle (180° − that) as the median across strokes. The target is ~30-40° of bend.
How to fix it
Adjust in small steps — 5 mm at a time — and re-film after each change. A deep bend (too low) can also come from cleats set too far forward, so confirm cleat fore/aft before chasing height.
Recommended drills
- •Raise/lower saddle 5-10 mm
- •Re-film from the side after each change
- •Confirm cleat fore/aft first
Run these 2-3x per week. Expect to feel a change in form 4-6 weeks in.