All projectiles follow similar paths (trajectories) called parabolas.
The exact trajectory followed depends on the launch angle and speed, but all have similar characteristics. In order to travel as far as possible the launch angle should be 45°.
These parabolic paths are evident in the motion of the centre of mass of any object that falls under gravity, whether it is spinning, twisting or otherwise in motion.
Here the centre of mass is on the motorbike itself, as it is so much heavier than its rider. All motorcycle jumps, regardless of the position of the rider, follow much the same path.
All photographs from the Red Bull X-Fighters website.
These are really nice images. The idea that the centre of mass can move while the object is flight gives rise to feats like the Grand Jeté in ballet (which is not quite as extreme a sport):
http://davidmcgloin.wordpress.com/2011/06/15/ballet-physics-the-grand-jete/
That’s a great link. Thanks.