Lance Armstrong's time-trial bike has been stolen from the Team Astana truck.

It was taken during the night before Stage 1 of the Tour of California. Armstrong rode that bike to a 10th-place finish Saturday in Sacramento during the Tour prologue, his first competitive appearance in his native country since beginning his cycling comeback last month.

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The thieves also stole race bikes belonging to Astana teammates Steve Morabito, Yaroslav Popovych and Janez Brajkovic.

Armstrong announced his comeback in September and joined the Astana team. He is reunited with Astana team leader Johanna Bruyneel, who teamed with Armstrong for all seven Tour de France wins from 1999-2005.