I've recently become a fan of 26" wheels, and fat tires. I do most of
my riding on city streets, and between the crumbling asphalt, subway
grates, and street-car tracks, fat tires are almost a necessity. I
don't doubt that skinny wheels roll faster, but I do doubt that they
roll so much faster as to make their tendency to dent rims, and get
flats worth it.
So run fat tires, what's the problem? All the bikes that have
chainstays wide enough to accept fat meats are mountain bike or BMX
style frames which also happen to feature sloping top tubes so you can
put the seat really low since most of the serious pedaling in those
sports is done out of saddle.
I want my top tube flat, and my seat stays tall because I keep my seat
high so that my legs are fully extended when I'm in the saddle. A long
seat post would get me up high, but that combined with the higher BB
of most dirt bikes makes me feel like I'm riding a folding bike.
Basically, I want a frame with road geometry, and fat 26" tires. Maybe
something like a Surly Steamroller since it's chainstays say "Fatties
Fit Fine". Assuming I use shorter cranks to compensate for the lowered
BB, would a rig like that be a good idea?