Lance Armstrong's time-trial bike was stolen from the Team Astana truck during the night before Stage 1 of the Tour of California.

Armstrong rode the bike to a 10th-place finish Saturday in Sacramento during the Tour prologue. The race is his first competitive appearance in his native country since the seven-time Tour de France winner began his cycling comeback last month.

A few hours after the time trial, someone removed four bikes from the Astana truck outside the team hotel in Sacramento. Armstrong's time-trial bike, which was closest to the door because he was delayed by a post-race trip to doping control, was taken along with race bikes belonging to Astana teammates Steve Morabito, Yaroslav Popovych and Janez Brajkovic.

"There is only one like it in the world, therefore hard to pawn it off. Reward being offered," Armstrong wrote, before jumping on his race bike for the 107-mile (172-kilometre) ride from Davis to Santa Rosa through a steady rainstorm.