Rudy:
The only true way to find the most aerodynamic position is to accurately measure your frontal area or spend time in a wind tunnel. Neither of these are very easy or practical for most riders to do.
Forget about wind tunnels, but you can measure frontal are by a fairly complicated process of taking a picture of yourself on your bike and measuring the size of the photo.
Image measurement techniques range from using graph paper to computer programs. Wear black clothing and photograph yourself against a white background if you try it.
Just as mass-produced clothing fits differently on different people, mass-produced bikes and equipment fit riders differently.
It's not really good to go off a picture of someone else. It's really impossible to say a cetain position is the only/best way to go.
Pros seem to change their aero positions all the time. Probably very little real testing went into any of the aero positions you see your favorite pro using, except at the very top like Armstrong.
Also, all aerodynamic positions reduce a riders natural power output but this is more than compensated for by reduced wind drag. So, in reality all aero setups will make you quicker, but are technically less efficient.
Your goals are more important. If you are looking to medal in a national championship, a slick/painful position could be the fastest setup, and the one you should probably use.
However, if you want to ride faster over 100 miles with friends, a more comfortable position is necessary. Cycling is a sport where a lot of experimentation and testing is often required to get things right.
Either way, any just about any aero postion will be faster than a conventional riding position.
Happy riding!!!
