Just checking through my notebooks.
Some useful facts for the wheel debate
26 x 1.25 (599mm) old USA sports bikes
26 x 1 1/4 (597mm) proper fast 26″ – old British sports bikes
26 x 1 3/8 (590) proper gents 26″ – old British roadsters
26 x 1 1/2 (584mm) foreign muck aka 650B
26 x1 (571mm) can’t think of a use for these except on a head down bike.
26 x 1.75 (559mm) USA kids bikes
and there may be another 26″ size – old UK carrier bikes – can’t find the details – I think they were E.A.1
But everyone knows that a gentleman would not be seen on anything less than a 28 x 1 1/2 (635mm), so the wheel debate is just the lower orders squabbling… 🙂