Just bought an old 20's bike with metal cald wooden wheels. It has single tube tires which from coker run about $350 a pair..... (that's almost the price of my first car.) The tires that are on there hold air just fine but are cracking but I'm afraid if I sit on it (I'm not exactely a light weight) that I'd ruin these tires. I'd much rather replace the whole wheelset with something that I won't be afraid to ride on. What can I use as a replacement? or.. is there any way to use clincher tires on these rims? I see that 28x 1 1/2 tires arent that hard to find in standard tires, but the single tube tires are expensive!