Knee-over-pedal-spindle is simple. Other recipes for finding optimal saddle setback start with putting the bike in a trainer. I'd rather experiment on the road. What are the symptoms of the saddle being too far forward? What are the symptoms of the saddle being too far back?

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Saura mon coeur que mon cul poise.

adapted from Rabelais

why use another method if the knee over spindle is simple and works?

I find my body intuitively sitting in the right position even if my saddle is in the wrong place, hence if I shift the saddle too far back I'll end up sitting at its nose. keep shifting it front and back and try it out. Go for a test ride and stop frequently to adjust. Don't bother with fitting rules like knee-over-spindle.

Knee-over-pedal-spindle gives a result that works ok in practice for me. I'm not aware of any reason to believe that it gives the best possible result.

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Saura mon coeur que mon cul poise.

adapted from Rabelais

Problem with knee of pedal spindle: imagine two identical riders but one has feet that are two sizes larger then the other. The only way to achieve the same leg joint angles on these two riders will be to have the saddle in two significantly different positions. One of these guys simply won't have their knee over the pedal spindle. It can work but be careful. A starting point at best.

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We've noticed an increase in positions a tad back from the KOPS idea. I'm probably a CM behind with good results.

Moving back increases the involvement of the glutes and makes high rpm somewhat more difficult. Moving forward increases involvement of the quads and makes high rpm somewhat easier. Many road racers and century riders prefer a somewhat back from KOPS position especially if they do a lot of climbing.

I set mine by how it feels. I aim for involving the quads and glutes equally. I wind up about 1-2cm behind KOPS, on a standard 73 degree seat tube road frame.

Some articles:

http://sheldonbrown.com/kops.html
https://www.stevehoggbikefitting.com/bl ... oad-bikes/