Racing cyclists are obsessive about drag reduction. This is about the only thing I have in common with them.
Today’s invention is a bicycle seat post for racing bikes.
When the cyclist stands in the pedals to race uphill, the seat post withdraws into the frame, thus lessening drag associated with having a long cylinder thrashing around in the airflow from side to side.
The seat might also be especially aerodynamic, with a tapering rear profile.
The rider would then simply touch the lowered seat with his behind when the hill was climbed, for it to rise back into position and lock in place.