CatEye computers always used to ask for the *circumference*. If you're using tyres which are *actually* 700x23, then this will be 210cm (pi x diameter = pi[62.2+[2x2.3]]). Tyre sizes are often pretty nominal, though - I'd measure them, which is very simple - just roll the bike along a tape measure laid out on the ground, measuring one wheel revolution from valve to valve, if you see what I mean.
While tyre is inflated and weighted by you to the normal riding extent. -- Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205 IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK ["]http://www.dai.ed.ac.uk/homes/cam/]
