Reducing resistance... continued

Body positioning is important; road cyclists use "drop bars" to allow themselves to reduce their frontal area, which helps reduce the amount of resistance they must overcome. Reducing the frontal area helps riders increase their speed and their efficiency over time. In addition to positioning, small details like clothing can also make a big difference in reducing "skin friction." Tight-fitting synthetic clothing is worn by almost every professional rider, both road and mountain. Many recreational riders are also wearing bicycle clothes for the improvement in aerodynamics as well as comfort.
Drafting.

Drafting is an important technique in road racing. Exploratorium Senior Scientist Paul Doherty explained, "The bicyclist, as he moves through the air, produces a turbulent wake behind himself. It makes vortices. The vortices actually make a low pressure area behind the bicyclist and an area of wind that moves along with the bicyclist. If you're a following a bicyclist and can move into the wind behind the front bicyclist, you can gain an advantage. The low pressure moves you forward and the eddies push you forward."

Suprisingly drafting not only helps the bicyclist following the leader, but the lead cyclist gains an advantage as well. Paul explained, "The interesting thing is by filling in her eddy you improve the front person's performance as well. So two people who are drafting can put out less energy than two individuals (who are not drafting) would covering the same distance in the same time." While the lead cyclist gains some advantage in this situation she still needs to expend much more energy than the cyclist who is following.
In road racing, bicyclists group together in a pack known as the "peloton" or a pace line called an "echelon." Cyclists who are part of the group can save up to 40 percent in energy expenditure over a cyclist who is not drafting with the group. To be effective drafting, a cyclist needs to be as close as possible to the bicycle in front of him. Many professional cyclists get within inches of the bicycle in front of them. The shorter the distance the larger the decrease in wind resistance.

Continued on the next page...