FYI: tire sizes: the first number is the width of the tire, in mm. i.e 130
The second number is height of the tire sidewall, as a
percent of the width of the tire,
not the height in mm.
the third number is the wheel size.
Here is an interesting tire size calculator and comparer:
http://www.discounttiredirect.com/di...nfoTireMath.do
It seems to work fine with motorcycle tire sizes.