I came across this image of a road bike with mtb tires on the fixed gear gallery and wish I could test ride it. If anybody has tried this, I am curious what they found.
Some people say that it makes the handling a bit awkward on turns. If that is not true, it would be a great conversion for 70s frames (Schwinn, Univega, Fuji, Peugot, Cenurion, etc.) whose rims are too heavy, rusty, and slippery in wet weather to be of much use.
To convert a road bike to smaller and wider rims/wheels one would first have to measure the width of the chainstay tube and fork. There would also be an issue of the rear hub not being not sized appropriately. This may not be an issue with rear rims that accept 5-7 speed freewheels, though I have not tried. If everything was OK wiht frame spacing, then next get some long caliper brake levers. For more info see Sheldon’s post, rest in peace.
The consumer analog are these 650Bs (588mm) being used on bikes by Rivendell, Ira Ryan and Kogswell Cycles– all seemingly fantastic frame makers. 650Bs are a comfortable middle ground between 700c (622mm) and 26” mtb (559mm) and provide the same wheel height as 700c with more tire volume and width. My only concern is that 650Bs are expensive and uncommom, and therefore difficult to replace and are not recyclery material yet. On my own bike, a 1974 Raleigh, there are 650A (590mm) rims that are pretty shot, but I am scared to take them off lest I cannot find another. I think the previous owner of the Raleigh also had the same issue, because the rims were rebuilt by the looks of the variegated nipples.
Why are the best things in life hard to come by, or are they hard to come by SO they are the best things? Can cheap second-hand mtb rims/tires be the next 650B-esque conversion for thrifty vintage road biker? The fixed gear rider from Tel-Aviv (pictured above) seems to think so. At the very least, I hope that these big volume road bike conversions help ease the spandex fad and bring road biking back from the podium to the pavement.