Radhaltung

How do you sit on your bike?

Enter your body measurements and your bike’s numbers – Radhaltung turns them into your riding position. See it in 3D and change the settings to watch what happens to your posture.

Calculating your riding position Two body measurements, your frame’s numbers — and you see how you sit. Muscles in your position Get to know the muscles your riding position stretches and shortens as you pedal — X-rayed, over the whole crank revolution. Training for your riding position What your position asks of hips, trunk, shoulders and neck, and a programme for it in 10–30 minutes. Compare bikes Two frames side by side: how you sit on each, and what changes.

• No sign-up, no cookies, no database. What you enter lives in this page’s address and nowhere else.
• Free and without advertising. Radhaltung is an independent project and stays usable without signing up.

What this page does not do: it makes no diagnosis and does not tell you where your trouble comes from — only someone who can look at you can do that. It counts no kilometres and no watts.

It does not replace a bike fitting. A fitter watches you pedal — where you compensate, how steady your pelvis stays, what is left of your mobility at the end of a long ride. This page sees none of that; it works from measurements. What it can do is make the invisible visible: which number hangs on which, what a centimetre of saddle height does at the knee, why a frame is too small. So it is not meant to keep you away from a fitter, but to send you there with better questions.