RadonRadon Bikes
Home ENGL> Support/FAQ> Correct frame size

For the calculation of the correct frame size we need your inseam and your body height. Furthermore you should indicate if you prefer to sit on your bike rather comfortably or rather sportingly. If you are not sure, we can advise you by phone if you call +49-2225-8888-222!

The inseam is the length of inner side of your leg. It is best to measure your inseam by using a water-level and a measuring tape. If you do not have a water-level at hand, you can also use a book or something similar. Now stand bare-footed (!) on a flat ground, clamp the water-level (or the book) preferably horizontally between your legs and pull it as far upwards as possible until it slowly gets unpleasant. Now measure the distance of the upper edge of the water-level down to the ground. The read data corresponds to your inseam.

For a racing bike:
Multiply your inseam by the factor 0,665.
The calculated value is the theoretical frame size in cm.
For a mountain bike:
Multiply your inseam by the factor 0,226.
The calculated value is the theoretical frame size in inch.

We call it "theoretical" frame sizes, because as also mentioned before, personal preferences can sometimes put this value ad acta. Thus many cross country-racers will e. g. choose a smaller frame size than calculated. This modification of the frame size should only be done by experienced bikers, beginners are better off with the "theoretical" frame size or with the expert advice of our hotline.

1,54 MB