Rampage":1jjj6vms said:Oh, same a a ring gauge for wedding rings etc.
The problem with the it that they measure at the to where it can get distorted
Follow the link. look at the picture of the gauge what do you see?
A ring gauge is effectively a cone. The 'ring' is very narrow so you dont need long stepped graduations. However. those boffins,knowing that the bicycle seat tube changes diameter slightly and have taken that into account.
Pro tool. Pro giving the advice. Pro uses gauge himself