cc is a measure of Volume not length. Cubic Centimeters.
[Don't they consider the metric system, subversive, in Texas?]
The numbers that count are a agreement between Tire/tyre and Rim Manufacturers.
They use a tire-bead seat diameter.. for 700C it's 622mm.
so look at tire sidewalls 622-32 is size & width.. Metric .
nearest fractional size 27 x 1.25" is (approximate), a 630-32.. not same..
The ETRO numbers are on the sidewall ..
circumference changes with tire width. of course..
Last edited by fietsbob; 10-30-12 at 02:49 PM.