There are three bits to the Olympic cycling; mountain biking, road racing and inside in the velodrome.
Mountain biking sees the riders race around a hilly course that may go through rivers and over rocks.
On the road there are two events, road racing and time trial. The road race is 239km for men and 120km for women. They all start together and the first past the line is the winner.
The time trial is against the clock over a much shorter distance. The riders start 90 seconds apart and whoever finishes fastest wins.
In the velodrome riders hare round a small indoor track that is on a slant from the middle out to the edge, which is called banked.
Riders use hi-tech bikes and outfits, that wouldn't look out of place in a sci-fi film.
Keep an eye out for the Madison event, where each team has two riders who take it in turns to ride. When they switch over one pulls the other along for a bit holding hands. As crazy as it sounds.
Who are the British hopes for Athens?
There are lots of really good cyclists going to the Games for Great Britain with two golds, two silvers and a bronze at the 2004 world championships.
One of the best is 20-year-old Nicole Cooke. She won Commonwealth gold in 2004 and was the youngest ever winner of the World Cup.
As a junior she won four world titles in a single year; the Road Race twice, the Time Trial, and Mountain Biking too.