Originally Posted by asgelle

That's the wonderful thing about geometry, I don't have to do the experiment to know the answer. Rotating the gravity vector 45 degrees to the rear will not change the relative position of the hands, hips or feet, nor will it change the direction of the force vector on the chainring. Since gravity plays no role in a balanced system, there will be no additional forces on the legs or cranks from the change in gravity. All this adds up to no change in muscle recruitment to move the pedals against chain resistance.