Originally Posted by
TheFort
Edit: I just saw your post above. You think the company made an error? Strange because they are emailing with me and quoted the same 385mm for the 56T in those emails.
Yeah, I found it on Geometry Geeks, but it's the same numbers. My logic (with a slight adjustment for my error in calculating compact geometry) is this:
The top tube is 13mm longer but with an extra 0.5 degree more laid back seatpost.
The reach should be calculated at the same height as the theoretical top tube, 560mm up the seat tube from the BB*
Basic geometry calculations say that eats up 4.8mm of the extra top tube length, leaving 8.2mm to be taken up at the front
*Note that this does not account for the fact that your seat height is relative to the BB. not the top of the seat tube, but that only accounts for another 0.1mm
Any actual experts on frame geometry wanna tell me if I'm right or wrong?