These are actually from Radio Shack. They are the "CR250R RC motocross bike featuring Ricky Carmichael". I searched the site but couldn't find anything more than replacement tires , so I don't know if they are discontinued or not. Good Luck.
I have talked to a couple of people who own the Ricky Carmichael bikes and they said they rocked and were very fun to drive. Myself, I have been jonesin' for an onroad bike like the Nuova Faor sp501. There isn't much racing for them but they look awesome.