As a jazz bassist, I occasionally take arco solos with my very average German bow. Any issues tend to be with intonation, not with bowing. This week I am a hired 'ringer' in a youth orchestra, and suddenly the bow is bouncing. Of course it's embarrassing - I'm guessing that the kids are thinking oh, my grandpa has Parkinson's disease, too - but it's also strange in that it doesn't happen during a jazz arco solo or while practicing one of the first couple of Bach suites. Typically the bow starts to dribble from the midpoint to the tip. In the two days left before the concert, I plan to try a few 'mechanical' fixes - more rosin, tighter bow hair tension, raising the endpin - though I fear it's more likely that the bounce is merely exposing my lousy bow technique. Can anyone recommend a way to eliminate the unwanted bounce?