Originally Posted by Chuckk

One thing to take into consideration is that bikes made for 27" wheels, or touring bikes with a lot of fender clearance (or both!) will have a higher fork crown to clear the wheel. That will give you a much shorter appearing steering tube - usually by a size or two.

A particularly high or low BB height can really fool the eye, too.

Also remember that the best deals are from folks that don't know what they're doing when they measure their bikes. The last two bikes I bought on CL have been advertised as 62 & 61, and they both turned out to be 59's c-c - perfect for me and probably mine because the stated size limited the interest.