Lance defends Leadville crown

Leadville - Seven-time Tour de France champion Lance Armstrong will defend his title at the Leadville 100 mountain bike race on August 14 and fellow American Levi Leipheimer will race alongside him.

Organisers announced the two American cycling stars and RadioShack team-mates, will be among a field of 1 500 riders who start at 10 500 feet and climb 2 000 feet more in the top US cycling high-altitude endurance challenge.

Armstrong won last year's Leadville 100 in a record time of six hours, 28 minutes and 50 seconds.

Leipheimer will be competing in his first mountain bike race.

The competition comes amid reports that former Armstrong team-mates and even sponsor Trek are co-operating with US federal investigators looking into doping allegations against Armstrong from Floyd Landis, himself an admitted dope cheat.

Armstrong has denied any wrongdoing and has never tested positive for performance-enhancing drugs.