Get Under The Wind
By coach Matt Russ
Up to 80% of the resistance you encounter on the bike comes from aerodynamic drag. Reducing this wind resistance is a key consideration in increasing speed. The more upright your riding position, the more aerodynamic drag you create. By lowering your torso towards the top tube, you essentially "get under the wind" by reducing your aerodynamic profile.
If you are a recreational rider unconcerned with speed, comfort should be your primary consideration. If you are a competitive cyclist looking for ways to get faster, your riding position should be gradually adjusted to make yourself more aerodynamically efficient. There are, however, sacrifices to comfort and perhaps power when you make adjustments to your riding position. These have to be balanced with the decreased drag the new position creates. There may be a small drop in power initially as your body learns to produce power in the new position, but you should gain a subsequent increase in speed.
Aero bars, as favored by triathletes and time trialists, significantly reduce drag but require a different fit and frame type than a traditional road bike geometry. Again, simply bolting on a pair of aero bars will not help you unless you can produce power comfortably in this position. You will need the right bicycle and a professional fit to fully capitalize on aero bars.
It is important to make small changes in your riding position over time versus large adjustments. If a new position is painful or causes an overuse injury, you should reverse it. If you spend most of your time in the hoods (on top of the brake levers), a good place to start is by switching to a lower hand position (drops) for periods of time. Start off with as little as 5 minutes and progressively increase the amount of time you spend in the drops. Eventually, you should spend a majority of your time here unless you are climbing a steep grade.
Once you are comfortable in the drops, you can lower your stem height. Lowering your stem height decreases the angle at your torso. Stem height can vary from zero to four inches below the height of the saddle. When you lower your stem height there will be less aerodynamic drag from your upper body, but power and climbing ability will be reduced. Lower the stem in small increments and let your body adjust to the new position.
Remember, the faster you get the more the air around you slows you down. If you can ride consistently over 20 mph, an aerodynamically efficient riding position should be a primary objective. The type of riding you do should also be a factor. Generally, the more time you spend in the saddle during your goal events the more comfort should be considered.
Matt Russ has coached and trained elite athletes from around the country and internationally for over ten years. He currently holds expert licenses from