Improve your cadence?...depends by what you mean by that. The dynamic and relationships have been explained above. It is more about your priority and the tradeoffs that will result. Generally...moving the seat forward as mentioned will open the hip angle and apply a bit more pedaling force which is desireable for a TT bike for example. This is however not without a downside or more would run a more upright seat tube angle and knee position more forward of the pedal spindle at 3 o'clock. With a more forward position you have more weight bearing on your legs and on your hands...your whole body CG is more forward. This will not only tire your legs faster but put more weight on your hands which is typically uncomfortable for the recreational cyclist. I subscribe to Sheldon Brown's writing on the subject. For a recreational cyclist, KOPS should be over the pedal spindle if not back 1-2cm...not forward of it for the above reason. If your objective is pure power, then move your seat forward with the related consequences.
George
Last edited by biker7; 05-13-05 at 06:24 AM.