The men's Keirin

Keirin

is a track cycling event in which racing cyclists sprint for victory. Keirin originated in Japan in 1948; the first Olympic competitions in the sport occurred in 2000....

at the 2008 Summer Olympics

2008 Summer Olympics

The 2008 Summer Olympics, officially known as the Games of the XXIX Olympiad, was a major international multi-sport event that took place in Beijing, China, from August 8 to August 24, 2008. A total of 11,028 athletes from 204 National Olympic Committees competed in 28 sports and 302 events...

took place on August 16 at the Laoshan Velodrome

Laoshan Velodrome

The Laoshan Velodrome is a velodrome that is located in Laoshan, Shijingshan District, Beijing, China. It was built for the 2008 Summer Olympics. The venue was tested during the UCI Track World Cup in December 2007....

.

This track cycling

Track cycling

Track cycling is a bicycle racing sport usually held on specially built banked tracks or velodromes using track bicycles....

 event consisted of multiple rounds. In each race, the four to seven cyclists in the heat covered 8 laps of the track. The first 5.5 laps were behind a motorized pacer called a derny

Derny

A Derny is a motorized bicycle for motor-paced cycling events such as during six-day and Keirin racing, or motor-paced road races. It is driven by a 98cc Zurcher two-stroke engine and by being pedalled through a fixed gear, typically of 70 teeth on the front chainring and 11 on the sprocket on the...

, which gradually increased speed up to 50 kilometres per hour. The derny then left the track and the cyclists then raced the final 2.5 laps to the finish.

In the first round, four heats were held. The top two cyclists in each heat advanced to the semifinals, with the rest of the cyclists competing again in the repechage. Four of those cyclists advanced from the repechage to the semifinals as well, for a total of 12 semifinalists. They raced again in two semifinals heats. The top three cyclists in each semifinal advanced to the final, while the bottom three competed in the 7th to 12th place classification race.

Qualification

Twenty-five cyclists competed in the Keirin. Chris Hoy

Chris Hoy

Sir Christopher Andrew "Chris" Hoy, MBE is a Scottish track cyclist representing Great Britain and Scotland. He is a multiple world champion and Olympic Games gold medal winner...

 (Great Britain) qualified directly by winning the Keirin at the 2008 UCI Track Cycling World Championships

2008 UCI Track Cycling World Championships

The 2008 UCI Track Cycling World Championships were the World Championship for track cycling. They took place at the Manchester Velodrome in Manchester, United Kingdom from 26 to 30 March 2008. Eighteen events were scheduled; the women's team pursuit being the only addition from the 2007...

. He also won the event at the late 2007 World Cup

2007–2008 UCI Track Cycling World Cup Classics

The 2007–2008 UCI Track Cycling World Cup Classics is a multi race tournament over a season of track cycling. The season began on 30 November 2007 and completed on 17 February 2008. The World Cup is organised by the UCI. The 2007–2008 series carries vital ranking points towards the 2008...

 event in Sydney, affording another position to qualifiers based on Union Cycliste Internationale

Union Cycliste Internationale

Union Cycliste Internationale is the world governing body for sports cycling and oversees international competitive cycling events. The UCI is based in Aigle, Switzerland....

(UCI) rankings.

Preliminaries

Heat 1

Rank	Rider
1	'
2	'
3
4
5
6

Heat 2

Rank	Rider
1	'
2	'
3
4
5
6

Heat 3

Rank	Rider
1	'
2	'
3
4
5
REL

Heat 4

Rank	Rider
1	'
2	'
3
4
5
6
7

Repechage

Heat 1

Rank	Rider
1	'
2
3
4

Heat 2

Rank	Rider
1	'
2
3
REL

Heat 3

Rank	Rider
1	'
2
3
4

Heat 4

Rank	Rider
1	'
2
3
4
5

Semifinals

Heat 1

Rank	Rider
1	'
2	'
3	'
4
5
6

Heat 2

Rank	Rider
1	'
2	'
3	'
4
DNF
DNF

Finals

Classification race

Rank	Rider
7
8
9
10
11
DNS

Medals race

Rank	Rider
4
5
6