Originally Posted by
MichaelW
Dont forget crank size and BB height.
You can decide on the required pedal-ground clearance for cornering, then factor in the expected crank size. Big riders with big legs need big cranks so you need to put the BB up higher to prevent pedal strike. Smaller riders use smaller cranks so you can lower the BB to give the same pedal clearance. A lower BB makes mounting the bike easier for a small person.
This.
It's rare enough to find off the shelf bikes which spec different cranks lengths for different sizes. Then when I find one I look at the geometry and find that they screwed it up and gave all the sizes the same BB drop.