Setback-why?

the blur said:

i just had a new bike built up for me and i wanted it to have the seat
tube canted steeper than normal so i could be over the pedals more, and
flex my hips less. in other words, i wanted a seat position farther
forward than the usual patella/pedal spindle position. i felt on my
old bike my hips were bothering me on longer rides because of the
height of the flexing. it seems the farther forward i can get, the
less flexed my hips would be at the top of the pedal stroke.
am i loosing power or endurance in this position?
why do almost all seatposts have setback? (mine has none)
how does this forward position change my muscle groups used?
how did the standard position get to be standard?
thanks for any insights

--
the blur

The "standard" position is knee-over-pedal-spindle (KOPS). There is
nothing magical about KOPS, but it is fairly easy to measure, and tends
to be a decent approximation of the "ideal" for most riders.

Tourers and long distance racers tend to favor a more rearward saddle
position which facilitates the use of the glutes and reduces the amount
of weight supported by the arms. Track and crit racers generally favor
a more forward (and higher) position which is better for high intensity
efforts and slightly better aerodynamics. Time trialists may prefer an
even more forward (and higher) position when they are using aero bars
and trying to get their backs as flat as possible. This is to reduce
the hip angle you mentioned.

I wouldn't recommend a forward position for a casual cyclist using
regular road bars. Too much weight is supported on the
hands-arms-shoulders. The more rearward position is generally better
for long term power production and comfort. Ideally you should have
little weight on your arms when riding on the hoods, and when climbing
a ~5% grade the weight on your hands should fall to about none (as
Hinault said, you should be able to play the piano while climbing). The
saddle should be level to very slightly nose-up, and you should feel
balanced in the seat (not tending to slide forward or back), with no
pushing or pulling on the bars (upper body relaxed).

If your saddle height is correct, the hip angle "problem" is best
solved by raising your upper body... which means raising your
handlebars. Most "racing" bikes are set up with the bars too low...
certainly for a beginning rider. Do you think raising the bars might
help? Maybe raising the saddle and the bars?

the blur said:

i just had a new bike built up for me and i wanted it to have the seat
tube canted steeper than normal so i could be over the pedals more, and
flex my hips less. in other words, i wanted a seat position farther
forward than the usual patella/pedal spindle position. i felt on my
old bike my hips were bothering me on longer rides because of the
height of the flexing. it seems the farther forward i can get, the
less flexed my hips would be at the top of the pedal stroke.
am i loosing power or endurance in this position?
why do almost all seatposts have setback? (mine has none)
how does this forward position change my muscle groups used?
how did the standard position get to be standard?
thanks for any insights

--
the blur

Knee over pedal spindle(KOPS) is a small 'c' constant, a starting place
more than anything else. If you are more comfy, less pain, with your
knees forward of that, ride that way. If you can do the rides you want,
are comfy, see no other drawback when you are riding, it is correct.

For a generic frame, with the proper seat tube angle for a certain
rider, it will have a setback seattube but that isn't wrritten in stone
either. If the seatpost is a little shallow and the KOPS position can
be reached with a no setback seatpost, then use that one. If the
resulting fit creates no pain or discomfort, it is correct. 'Fit' is an
art, not a science and often 'fit' people get all worked up with
numbers and what is supposedly 'proper', but the person's input is the
most important part. I like to be a wee bit low and aft, when ooking at
knee bend and KOPS...works for me, never have any pain...no real need
to worry about 'power'...