Janet, a note on actual vs advertised tire sizes:
The Schwalbes I've used (26 x 1.6 M'thon Supremes, and 700 x 35 M'thon Racers) have been up to 3 mm less than advertised width when inflated.
> The Racers measure 32 mm, not 35, and
> The Supremes are 39 mm, not 1.6"/40.6 mm
I've found this discrepancy to be common on other tires I've used, as well -- Conti's and Vittorias in the 700c size, and Maxxis and Compass tires in the 26". The difference betw adverised and actual differs, but is often around 3 mm.
Jan Heine says that rim width can affect the inflated width of a tire, and he's usually pretty good on this matter, but my Raven has a rear rim that's wider than the front, and the inflated widths of my Supremes, the Maxxis, and the Compass tires are all identical, front and rear, and they're all below advertised width. (Compass' adverts say that their tires' actual inflated width is as advertised.)
The only I have which is close to its advertised width is a Bontrager 700 x 32. Its actual inflated width is 31mm.
My experience suggests that a "32mm" Supreme might be 30 actual. So, you might have a bit more latitude than you think. Best to check with your supplier, and see what they say.
Good luck,
John
