You got farther back on the saddle to apply more leverage to the pedals. Good. Much of the time riding, however, you aren't really sprinting, but rhythmically spinning the pedals...which works better a little farther forward than your hard pushing, farther back seat position. Unless you have thighs of steel and a heart to match and a strong, flexible back, be careful pushing that seat into a permanent "push" position.
Fit being relative you might consider that your original seat position was too far forward, which would make a farther back seat seem more comfortable and efficient. If your saddle was close to farthest back already, are you sure your frame (top tube) and stem extension are ideal. As people always say, you might take the bike back to the shop to have them look at your set-up on the bike.
*** I'm probably wrong, but don't B-17 have unusually short saddle rails?
Last edited by CrossChain; 05-22-07 at 06:34 PM.