Nope you can get 700c in lots of widths, at least from 19mm to somewhere around 30. All that stuff has to do with something that may have seemed like a good idea at the time but actually makes no sense, and now it's wrapped up in a giant cluster**** with lots of other things that seemed like a good idea at the time. For example, they call 700c "28 inch" in Germany even though it's "29 inch" when it goes on a mountain bike in North America; and even though 622 mm is just under 24 1/2 inches . Edit: and even though "27"" rims are bigger than 700c by around 8mm.