Not long ago I acquired some some 760 x 90 Michelin tubes. I took a pass on the English tyres, as they appeared just too small to fit 30 x 31/2 rims. I'm going to use these tubes in some 30 x 31/2 tires and see how they do. Has anybody else tried this?
Dividing by 25.4 results in 29.92" × 3.54" but will the bead do what's it supposed to do on a clincher rim?
The numbers look pretty close, don't they? But when I set the American sized tires against the American rim, then did the same with the English tyres and saw the difference, I thought, "There's no way those tyres are going on that rim." As long as the tubes work, I don't care. The tyres are somebody else's problem.