amediasatex wrote:bgnukem could you give us an actual on-bike measurement of BB -> saddle top in cm as I can't see how your maths is working out?
36.5in inside leg is 92.7cm
a 57.5cm frame + 450mm seapost, with 100mm in the frame means 57.5cm + 35cm = 92.5cm from BB centre to saddle rail clamp, assume another 20mm (racy thin thing) to 60mm (brooks B17) of saddle height, lets be super conservative and assume only 20mm, that gets you to 94.5cm from BB to saddle top.
Which would mean when sat on the saddle, with your legs dead straight dangling they are still 2cm short of reaching the BB, lets give you 20mm of shoe thickness and assume you know reach the BB, but that still leaves the cranks, another conservative assumption of 170mm cranks means you're 17cm short of reaching your pedals, even if you point your feet down straight down it seems unlikely you could pedal like that.
Using the oft quoted Lemond method* of 0.883 x inseam would yield about 32-33 inch from BB to saddle top for someone with your length legs, lets assume that's conservative and you need a full inch more, which would be unusual but not unheard of, 34in is roughly 86.4cm, lets call that 86.5cm for ease.
86.5cm - 57.5cm = 29cm
29cm - 2cm (saddle thickness) = 27cm
And lets whack a full 100mm into the frame, that would mean you need, at worst, at 370mm long post, which does negate the use of a 350mm post unless you're happy with only 80mm insertion, and if any of my 'worst case assumptions are out you might actually be able to get away with the 350mm posts, but a 400mm post should work fine, and they are plentiful.
Does the above all work out or have I made a glaring error? I'm not trying to be awkward or catch you out I just can't see how you need a 450mm post to make that frame work and trying to understand
The only thing I can think of is if your 57.5cm frame is a 'virtual' measure on a compact frame with a seat tube that's actually significantly shorter than that, is that it?
I've had to fit some quite tall people on to bikes over the years and only twice come across people who genuinely needed a 450mm post, the first one was a whisker under 7 foot tall, and the other was determined to use a frame 2 sizes too small for him, and he was the same height as you.
* which I don't believe in but gives us a rough ballpark as a starting point for example purposes.