My first road bike had 27 X 1 1/4" tires on it. I had no problems riding anywhere, and still got some flats. Over the years I saw tires size shrink down to 700C, and widths shrink to 20. Now people are rediscovering why wider tires are better than those 20 rubber bands. Personally, while I tried 20s, I never liked them. Heck, I don't even care for 23s. I like my 25s, and for the past two years have been mounting 28s on everything.