Might want to make sure the bearings on the front end - axle, steering, etc - are all good. It could very well be the combined forces of the wind knocking you around enough to create unintended steering inputs.
A steering damper might help, but I'd check the bearings first. If the previous owner (was there a previous owner?) did a lot of wheelies and such, it could have messed the bearings up.
A steering damper might help, but I'd check the bearings first. If the previous owner (was there a previous owner?) did a lot of wheelies and such, it could have messed the bearings up.