Originally Posted by
topflightpro
Typically, when climbing seated, sliding back on the saddle is more beneficial to sliding forward. As you move back, you better engage your glutes and hamstrings. Thus, you are bringing in muscles that aren't used as much when riding on the flats. It helps save your quads for once you are done climbing.
Sliding forward, or being on the rivet, generally allows you to gain more power while maintaining a low profile. But aerodynamics are less of a concern when climbing.
I don't think I agree with any of that.
Seated, muscle use is consistent, i.e. same muscle groups, same contributions. Sliding front to rear is not going to change that, though being too high up (too much leg extension) would reduce the powerful hip extension.
Sliding forward "on the rivet" is a powerful position not because of aero, but because it effectively reduces saddle height and lets you make more power.
Anyway, I've been riding and climbing long enough to know that sliding backward on the saddle does not make more power for me, but that may be due to setup issues like saddle height, saddle position, crank length, etc.