Originally Posted by
chaadster
Aside from the fact that seat potion relative to BB can be set in other ways than the seat tube angle (e.g. saddle rail position in seat post clamp, seat post head layback), what I was getting at is how did you relate seat tube angle to long arms/legs and short torso? It seems to me that top tube length, bar size and stem length would be more important to fit than ST angle... I'm not saying I have perfect understanding-- which is why I'm asking-- but I simply have never thought of seat tube angle as an indicator of how a rider will fit on a bike.
I can see slack ST angle affecting the ride character of a bike, but relating it to fit based on body type is foreign to me.
The seat tube angle affects where your body will be positioned in relation to the bottom bracket. On most bikes, with most people, this relationship is irrelevant. However, on smaller bikes, the tendency is to steepen the angle which can cause a rider to sit too far forward on the bike if they have relatively longer legs than the mean population the bike is designated for. I brought up my personal dilemma to state that solely based on my height, I should be able to ride a size 50 or possibly a 52, but due to issues with body position on the bike and reach, I fit best on bikes towards the smaller end of the spectrum. This is in a way the entire basis of the dilemma, as larger sizes typically do not have the same issues with geometry.