Hi, I wish to know how are these numbers derived?
The numbers refer to the diameter (in mm) of the seat tube to which the clamp is attached. Is that the information you were looking for?
Check the spec sheet for your bike, if you have it. If not, do what I did - take a piece of string and wrap it around your seat tube to find out the circumference (in mm). Divide the circumference by 3.14. Voila!
Cirumference = 2 x r x pi = diameter x pi
(And yes, I am a big dork)
yes it is. thanks alot.. now i know...