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The most critical part of a bobsled run is its start. Teams focus on
explosive starts because momentum at that point strongly affects the
sled’s speed throughout the course. Saving one-tenth of a second
during the start often translates to saving one-third of a second on
the run as a whole.
To set the bobsled in motion, team members sprint while pushing the
sled forward. They run for about 50 m (164 ft) and then leap into the
sled just before the first turn, assuming streamlined positions for
the remainder of the run. The driver occupies the front position and
steers the sled. The brakeman, in the rear position, operates the
brake. On a four-man bobsled the two middle sledders contribute
mostly during the start, although they also shift their weight during
turns. On the course, drivers try to steer through the turns
smoothly and to prevent the sled from skidding into the walls. The
greatest challenge is to maintain a tight line on the banked curves,
not allowing the sled to drift high up the turn. After the finish, the
brakeman pulls up on the brake to stop the sled.
The basic techniques used in two-man and four-man bobsledding are the same, but because four-man sleds have two extra sledders, they are
faster. They gain power from the extra push provided by the middle
sledders at the start, the sledders’ additional weight, and the
increased weight of a larger sled. The increased speed and weight make
four-man sleds harder to steer than two-man sleds.
Bobsled competitions involve training runs and two or four heats, with
the lowest combined time winning. Racers often use the training runs
to experiment with different strategies.