how much smaller frame sizes are you guys going with making TT bikes? I ride a 61, and my dad wants to sell his old specialized (i think it has 57.5 TT, i ride a 590). I was thinking of getting it off of him and throwing bull horns and aero bars on it to ride in TT's next year. I was also thinking that possibly with the smaller size, i may not have to get a reverse seat post because the seat to BB is more forward than i am used to riding to begin with.
Is the forward seat post merely for the increase in breathing efficiency? or is there a mechanical advantage as well?