Slide 1
Climb onto your bike and stretch out one leg.
Place your foot with the heel on the pedal at the lowest point of its arc.
Your knee should now be straight
If you are sitting square on the saddle when in this position, the saddle is at the right height.
Slide 2
How to pedal correctly:
The heel position on the pedal is only required for adjustment. When cycling, the ball of the foot must be positioned exactly on the pedal axis. Then with a correctly adjusted saddle height your knee also stays slightly angled at the lowest point of its arc.
Slide 3
You are not pedalling correctly if the middle of your foot is over the pedal axis.
Slide 4
A short test ride will soon show whether the saddle is too high. If your pelvis tilts to the right and left when pedaling, the saddle is too high. If it is too low, you will probably only notice this after many miles of riding when your knees start to hurt.