Fred Rednor wrote (snipped):
> C-t-C tells you nothing
> about the true frame size, unless you're also supplied
> with the diameter of the top tube [...]
Uh, no disrespect intended, but I believe your argument is circular. We are trying to define what the "true framesize" is, and many believe that is the C-T. To those folks, the true framesize is the C-T, and the tube diameter is quite irrelevant.
I'm pretty ambivalent about this argument because I think it is so unimportant, but I have always used C-T and see no reason to change. C-T tells you two things directly that C-C tells you only indirectly or not at all: How long a seat tube is needed to build the frame, and how long a seatpost will be needed given the rider's saddle height. All the points in favor of C_C seem pretty theoretical to me - I haven't seen a real practical advantage to it.
Mark Bulgier
Seattle WA USA