Originally Posted by
Bad Lag
If your brakes allow you to lower the pads down that extra little bit, get 700C wheels
If your brakes do not allow you to lower the pads that extra little bit, get 700C wheels and some new calipers.
Conversely, [MENTION=487286]J.S.[/MENTION], if you find a nice pair of 27" wheels for free or cheap, that works pretty well, too. No new calipers needed. (And again, your old brakes may well work with 700c, too. If any of your old road bikes have 700c, swap them in for a test fit)
It's true there are a lot more tire choices with 700c, but there are plenty of good ones with 27", too.