Nick.....different geometries make a difference for sure and this was largely what I was getting at. Plus my first generation Slice I can train on 32 mm tires. I can barely get a 25 mm into my P3 cut out for training. Different athletes have different needs....not all of us have the same needs so please accept that. Jonnyo gave a perfect example of a different frame dimension bike that will ride differently. The S3 vs R3 comparison was a good one given the geometries from what I understand are the same. If we compare bikes with different geometries and different tube shapes (which is what I am really referring too), then there is some difference, the extreme example being the Dimond with different tube shapes. If not all bikes set up with the same contact points would be identical regardless of the how the frame is distributed under the contact points, which we know is not entirely accurate.