Originally Posted by
andr0id
In practical terms, you are correct. You adjust your saddle to the point you don't slide forward. Not a degree more or less.
Hip angle useless if a rider is constantly fighting to maintain a correct saddle position.
Very few riders tilt a saddle too far back, far more tilt it too far forward and are often not even aware they slide forward as they subconsciously adjust position or push back on the handlebars.
Sliding forward with a level saddle is fixed by moving the saddle aft until, riding down the road normally with the hands on the hoods, one can lift one's hands off the hoods without sliding forward. Not by tilting the saddle back. You shouldn't feel the saddle nose at all.
If you can't move the saddle back far enough, you may not have a setback seatpost. I haven't heard of anyone who couldn't balance on their saddle who was using a setback post and a saddle with normal rails, i.e. not a Brooks.