IR's multiple build thread.

People get back pain if the curve over their back isn't smooth.

So to stay aero and comfortable closing that hip angle is the way. Or sack off aero, go for power and stay upright. Both work.

IMHO etc, etc.

Also a position you can pedal fast in.

I have to come up a bit to hold the highest cadence.

IMHO etc, blah...

I may perhaps be able to bend more forwards but my back doesn't look bent/curved if I check position in a window reflection on the Gazelle. I have a short back though. It may come down to anatomical differences... :)