Well, I think the issue in my situation (but I am no biomechanics expert) is getting the pedals
through top-dead-center (tdc) at the top of the pedal stroke, and bottom-dead-center(bdc)at the
bottom of the stroke in high torque situations such as hill climbing as well as pedaling style. I
dont spin fast, never did, never will, but I can spin fast enough for maintaining speed in crits.
With the seat farther back, one can get the pedal over TDC and BDC easier, as it utilizes thigh
muscles and hamstrings better (while sitting down climbing). Again, in high torque situations such
as hill climbing or gear mashing, but not necessarily in situations such as higher RPM spinning
where I find myself sliding forward on the seat for those situations.
With longer cranks, I found myself having to slide the seat back in order to get the pedals over TDC
and BDC without my knees saying something. Sure, I can move the seat forward like I see triathalon
bikes, but in my mind, that defeats the leverage advantage of longer cranks.
FWIW, I dont think moving the seat back is "sacriledgeous" as I primarily sit while climbing and
time trialing and turn relatively slow RPM's. On steep long climbs (excess of 12%), standing is not
an option as the rear wheel lifts, so one has to sit so that they are evenly balanced between the
front and rear wheels and grind it out. A seat farther back helps accomplish this along with long
cranks. When Davis Phinney first raced pro in Europe with 7-Eleven, one of the first things he was
told was to move his seat back. In looking at pictures of Eddy Merckx climbing, he is pretty far
back in the seat.
That has been my experience but I dont preach it as gospel.
-Sheldon
[email protected] (Andrew Bradley) wrote in message
news:<
[email protected]>...
> Sheldon:
>
> > I am just under 5'8" and grew up riding 170 length cranks since I was a Junior 25 years ago.
> > This year I got a new Specialized S-Works bike that came stock with 172.5 cranks.
> >
> > The first thing that I noticed was the improved leverage, but I had to slide my seat farther
> > back on the rails in order to keep my knees happy. Subsequently, I also had to ride a 1cm
> > shorter stem than what I would ride normally to accommodate for the seat being farther back.
>
>
> Backward is a strange way to go, sacriledgeous even. Moving up a full 2cm in crank length has me
> nudging the saddle slightly forward.
>
> If you feel comfortable that way then fine, it's just hard to understand why you would. How much
> farther back did you slide your saddle for such a small crank length change?
>
>
> > With longer cranks, I could not have the seat as forward as I did with 170's. Insofar as being
> > able to spin, no problems, I just slide forward on the seat.
>
> That's cheating, sliding forward on the saddle defeats the object of spin.
>
> Andrew Bradley