Originally Posted by
lazerzxr
Also you need to understand that "reach" has nothing really to do with top tube length. The reach of a frame is measured from the centre of the bottom bracket to the centre of the TOP of the head tube. Hence reach is unnafected by saddle position but is effected by spacers under the stem.
This is interesting to me. Why wouldn't you want to consider the saddle's position when determining reach? I would expect the desired reach to be a product of your torso and arm lengths, which would start where the saddle is. Of course, you wouldn't want to move the saddle to change reach, but I don't understand why its position isn't a factor in what stem length you end up choosing.
Also, I've never heard a reference stating how a frame's "reach" is officially measured, and never thought it was ever a real number since reach is a function of the frame plus cockpit parts put together. I've never seen a manufacturer publish "frame reach" in their geometry charts.