Originally Posted by
kwmcd
I've seen a pretty radical range of sets ups on this site and would just like to hear a little bit more about them, why you choose the stance you have and what kind of riding you do (short rides, racing, long rides etc.)
I never new 3 years ago when I got into biking how many different ways you can fit a bike, I always assumed there was one right fit (how the shop set me up) and till recently when I started taking a real interest in biking (other than solo rides with no knowledge of the sport) I never questioned the set up.
Get and read the book
Bicycling Medicine by
Dr. Arnie Baker. He explains a bit about the purpose of different bicycle fits.
For example, here is some of what he has to say about saddle height:
"Seat height is a compromise between aerobic economy, aerodynamics, bicycle handling, injury prevention, muscle fatigue, stroke fluidity, and power.
...
... Base the seat height on the angle from the horizontal formed by the knee at the bottom of the pedal stroke. This angle is measured in degrees of flexion. With the lower leg extended straight out, this angle is zero degrees by convention. As a starting point, many racers are best positioned so that the angle of the knee is 25 degrees. This is a good compromise between aerobic economy, muscle fatigue, stroke fluidity, and power.
...
Aerobic economy and power can be improved with a higher position: a knee angle of 15 to 20 degrees.
...
More control can be obtained with a lower position: a knee angle of 30 degrees. This is important, for example, when riding a bicycle on a steep velodrome.
Riders with pain in the anterior (front) knee - due, for example, to arthritis or patellar tendonitis - do better with a higher seat position and a knee angle of 15 to 20 degrees. Riders with pain in the posterior (back) knee, in the Achilles tendon, or in the back of the calf or thigh do better with a lower seat position and knee angle of 25 to 35 degrees."
(pages 119 - 120)
"A seat height that results in 25 to 30 degrees of knee flexion when the pedal is at the bottom of the stroke tends to result in the least injury but is not optimal for cycling power or aerobic efficiency.
The higher your seat, the more likely you are to have pain in the back of your knee, Achilles tendon pain, or buttock ache. Those with limited flexibility are the most likely to have problems."
(page 148)
But no, there isn't one single right fit. There's a reason for different setups, and they depend on the type of cycling you do, the terrain you ride on, your flexibility, weight, whether or not you've had a recent injury, and many other factors. Your fit will also change from year to year as those factors change too.