Originally Posted by
GV27
I was just thinking back to the discussion a couple months back about compact geometry. People kept crowing about "smaller triangles" being orders of magnitude stiffer. So here's my question. When you have roadies constantly in search of ultimate stiffness and carbon construction bringing the weight of a bike down well under UCI regs - why are modern race bikes not all mixtes? Not only are the triangles WAY smaller than even a compact frame, there's an extra one......
Well, for one thing, weight isn't the only UCI reg... My (very limited) knowledge of the rest of them doesn't provide a clear reason you couldn't do a mixte, but significant departures from what all the other bikes look like generally run afoul of something...
The extra triangle only provides more stiffness to the seat tube, which is irrelevant. And the two-continuous-tubes is really an advantage specific to steel, so moving carbon frame shapes nearer to mixte geometry is really just moving the top tube/seat tube/seat stay junction lower, which some frame builders both advocate and do.
Is there a reason not to go all the way down to a straight mixte-like line, and if so is that reason technical or regulatory? Beats me.