Key idea
At the bottom of the pedal stroke your leg should be almost straight, with a slight bend in the knee (around 25–30°). Too low and you grind with a bent knee; too high and your hips rock to reach the pedal.
The quick method: heel on the pedal
- Lean the bike against a wall Or have someone steady you, so you can stay in the saddle.
- Put your heel on the pedal At its lowest point, with the crank pointing straight down.
- Your leg should be completely straight In this heel position, with the saddle level and your hips not tilting.
- Now pedal normally, on the ball of your foot That swaps heel for ball and gives the correct slight knee bend automatically.
- Adjust in small steps Loosen the clamp, move the saddle 5 mm at a time, re-tighten and ride. Small changes make a big difference.
Let your knees tell you
Pain at the front of the knee usually means too low; pain at the back usually means too high. Adjust a few millimetres and give it a couple of rides.
Two more quick wins
- Saddle tilt: start level (a phone level app works). Nose-up digs in; nose-down slides you onto your arms.
- Reach: if you feel stretched or cramped, the stem can be changed — but get a shop to advise, as it affects handling.
Don't pass the minimum-insertion mark
Seatposts have a max-height / min-insertion line near the bottom. Never raise past it — too little post in the frame can crack it. If you need it higher, you need a longer post or a bigger frame.