Originally Posted by
Carbonfiberboy
OTOH, the Comp. Cyclist system specifically says to do it in cycling shorts and apparently, in socks, feet 8" apart. It's like I said: do what the calculation requires. Garbage in, garbage out.
The 8" spacing would tend to mimic the stance while feet are on the pedals, so I like this approach - if you have to pick an arbitrary criterion, it's probably better if it mimics the actual riding position. If you instead assume you should place your feet shoulder width apart that might be a little wider. If you set up the triangles on paper and calculate the error introduced by making it shoulder width versus 8" (or vice versa) I'm sure the difference will be very small and for my fitting I would neglect it. I also suspect the difference found with actual cycling socks versus barefoot is less than 1 mm, but ... I don't really know. I don't fit other people so I don't have to be Right and Correct. I just have to make my body happy. One reason I take such a lax attitude is that after I have computed the starting point for saddle height, I'm going to (following Carbonfiberboy's often-stated and excellent advice) adjust the height based on riding, to optimize my hip rocking and whether I am stable on the sit bone platforms of the saddle, and have managed pressure distribution against my undercarriage.