I am totally inflexible so I can’t get any power if I lie all the way down in aero position. People here told me I might as well use a road bike, which I have been doing. Question is, if I am already catching tons of wind sitting up, does it help at all to upgrade the wheels on the bike or is it moot?
Getting into an effective aerodynamic position does not require a high degree of flexibility. Certain positions with significant saddle to handlebar drop (well in excess of what Dan Empfield’s formula indicates) do require a higher degree of flexibility than is indicated for a position with closer vertical proximity between handlebars and saddle.
A key component to good aerodynamic posture is rotating the entire position forward and maintaining a relatively “open” angle between the torso and the femur. Athletes tend to gravitate toward this orientation and this is one reason people tend to slide forward on their saddle when using aerobars on a road configuration.
I wager you can ride relatively aero compared to a standard road position. It is just a matter of good positioning by your bike fitter. One thing for sure, no one can ride well (or optimally) in a bad position.
It seems that there is this (mis)impression that an aero position needs to be absurdly low, similar to a Bjorn Andersson or similar extreme orientation. That is wrong. The reason why the positions of an Andersson or a Boardman (with 22cm between the top of his saddle and the top of his elbow pads) are so recognized and celebrated is because they are so unusual. Those positions generally are not applicable to the majority of riders.
Another thing I am adverse to is the term “aggressive” which is sometimes incorrectly used to describe an extraordinary position, usually a significant differential between saddle and handlebar. I would suggest that if a position is “aggresive” as the term is (mis)used in common referance to a cycling position that a more proper vernacular would be “extremely low”. The (mis)sue of the term “aggressive” seems to suggest the concept of an effective aero position may be out of the reach of a more pedestrian rider. That is wrong.
Study this. It might work for you.