Originally Posted by
whatwolf
Want: 700 x at least 32mm tires, anything knobby/cross-like. Gumwalls a plus but not needed. Weird colors OK (winter beater). Ideal would be a more heavily used set of Challenge Grifos.
PM with any offers! Thanks all.
If you're considering new and have the clearance, you might try the Continental Cyclocross tires from Rivendell:
http://www.rivbike.com/product-p/t108.htm
I put a set on my RB-T for dirt-road riding this summer and liked them a lot.