Joined: Jul 2002
Posts: 40,863
Likes: 3,115
From: Sacramento, California, USA
Bikes: Specialized Tarmac, Canyon Exceed, Specialized Transition, Ellsworth Roots, Ridley Excalibur
I used the calculator that MrRamonG posted above on a road bike a few years ago. For what it's worth, it was a fun little project, but in the end it was a bigger pain in the ass (and expense) than just finding a decent frame with horizontal dropouts.