The Big Fish star was cruising around on his chopper a few weeks ago when he took a nasty spill and banged up his precious ride.
A concerned passerby notified the police, and McGregor confesses he was mortified when a fleet of first responders arrived at the scene to survey the accident.
He tells U.S. TV host Jay Leno, ""I made a real idiot of myself. I was in front of my mate Craig, we were two minutes away from my house... and we were going into a left hand (lane). And when you get the side stand on the ground, it sprays sparks up behind you, and that looks really cool. But what doesn't look so cool is when you follow the sparks and the bike slides out that way, which is what happened to me, 'cause I sort of pivoted the bike on the side stand 'til the wheels came off the road...
""It slid nicely and I thought, 'OK, it's not too bad, I didn't hurt myself very much,'... and then the bike went boom - so it... damaged both sides of this expensive and really beautiful motorbike.
""(Then) a jogger ran up... and said, 'Are you OK? Are you OK?' And I said, 'I'm fine, thank you very much,' and so I pulled the bike around the corner - I didn't want any paparazzi. I thought, 'This is embarrassing enough as it is'. And I guess the jogger phoned the police and said, 'There's a guy that's had an accident'. So, two seconds (later) around the corner, a fire engine arrived, the sheriff, and the cops. All three. It was a triple whammy. Literally, they said, 'Are you OK?' I said, 'I'm fine,' (and) they went, 'Can we get a picture?'""
However, the thrill-seeking actor insists all is not lost: ""It's (bike) being fixed as we speak in Brooklyn (New York).""
McGregor's biking escapades have become legendary - he filmed two globe-trekking TV documentary series with pal and fellow motorbike enthusiast Charley Boorman.