I thought it was just how they fit 700c bikes for really short people, because you dont see larger frames with 90* seat tubes.
Normally the smallest frame usually have a 76/77 degree seat angle, but looking at NJS Export, there's a fair amount of small frame with a near 90 degree seat angle.
Normally the smallest frame usually have a 76/77 degree seat angle, but looking at NJS Export, there's a fair amount of small frame with a near 90 degree seat angle.