so i picked up a cheap wheel this weekend from craigslist, but i'm not sure of the size. the rim is definitly a 700c, but i'm not sure the width of tire i need. the rim is 18mm across from outside edge to outside edge.

anyone know? help?

thanks.

you oughta be fine with whatever. lots of folks here go with 23 or 25mm, so if you're not looking to use some fatties, that oughta be fine. i doubt you'll have trouble with anything you want to run, though. i think that's about standard wheel size.

yeah, i usually run slicks... but then again i've always known the exact size i need for all my previous wheels.

700c is 700c. Anything that says 700c or 622 on it will fit. You probably shouldn't put a tire narrower then the hooks on a wide rim and some would say that you shouldn't put a wide tire on a narrow rim but I disagree.

18mm is not abnormal for the exterior width of 700c rims either.