 One such adjuster mounts on the existing saddle clamp and allows up to 40 mm of "increase" or "decrease" in the fore-aft position of the saddle.Another method for "increasing" the fore-aft adjustment is the swept-back seatpost, where the seatpost has a curve in it over the six inches or so before the saddle.Because of the gentle sweep of the tube, the top part of the seatpost cannot fit within the seat tube, so this solution is useful only for high seat positions.