willmac wrote: ↑Fri May 17, 2019 5:47 amTobin, I’m not going to get into an argument but at my saddle height, if you’re red line that you’ve drawn, vs the actual design calculations is wrong, which is highly likely as that photo may not be perfectly square, then you will get significantly wrong numbers. One degree is worth nearly 15mm so I will take the design engineers numbers rather than some work done in paint on a laptop somewhere
I mean you just replied, so you're continuing an argument. Look it's simple, the photograph depicts a real bike, and yes I measured the roundness of both wheels to confirm that the bike is on a plane perpendicular to the FoV. The geometry chart depicts...nothing...it's a drawing. The circle on the seatpost is nothing more than a metal lug for the clamping mechanism. I don't know why you keep talking about it. It's obviously not even in the same spot on the 15mm post.
Given that the depth of the seat tube is consistent across all sizes, the setback perpendicular to the seat tube will be consistent on all sizes. Yes, the horizontal setback will change with the STA, but that's beside the point. The seatpost is labeled as a 25mm setback post because it is set back 25mm perpendicular to the STA. The additional setback of the ST relative to the BB-c will also always be the same on all sizes. I just prefer the Trek way of reporting the setback of the seatpost...as a value relative to the line drawn through the BB-c at STA. In other words, the Cannondale "25mm" setback post should be listed as a 38mm setback post, especially since it can't be used on any other bike. Likewise it would be inane for Trek to call its 25mm setback post a 50mm setback post just because the clamp center is 50mm aft of the center of seatpost.