Why does bike do this?

I usually ride my KTM 300exc but last weekend rode my friend's '01 CR250 and noticed something different going over a jump. My bike jumps straight and true. But when I jumped the same jump on his CR250 the rear of the bike would hang out a bit to the right as I went in the air. When I brought this up, he said it did the same thing on him and always has.

I did notice watching the Unadilla outdoor national last weekend that all the fast guys' bikes did the same thing coming off those big jumps. They just gassed it before they hit and it seemed to straighten out.

Anybody know why this happens? I was guessing it's due to the torque of the rear wheel, but the "right hand rule" we learned in physics would say that would push the rear left, not right. It also doen't explain why that doesn't happen on my KTM.

Thanks Gomer. Since this doesn't happen to me on my KTM, and since my friend just had his swingarm bearings repacked at a local shop, we'll doublecheck the wheel alignment. I know sometimes the little guide marks in the back of the swingarm aren't exact, so maybe that's what happened.

See you again at DirtWeek this year!