I queried that too, he has customers using it in sportsbikes: and also in his own R1, as it has no friction modifiers, no clutch issues, swears by it. Bike engines are built to easily the same tight tolerances as our engines; if not tighter. Also, if you look at the guys tracking R35 GTR's, they're using significantly heavier oils than std. In any case, I'm sure this will bring out some discussion.