[FastHarley]

Try This

Check your tire air pressures first, if the problem is still there then pull the wheels and check the wheel bearings. Check the bearings in the pulley also. If all that checks out then have a look at your swing arm bushings.

Add after this is done as Frankie suggested, head bearings, than (on my DIY page) Steering Shakes, What The Manual Doesn’t Tell You > Do It Yourself than > Steering Shakes, What The Manual Doesn?t Tell You Than open http://www.motorcyclemetal.com/downloads/Steering Shakes What the manuual does not tell you.pdf

You can also go back to my DIY (Do it yourself) and maybe try this:

Harley Davidson Wheel Alignment Made Simple >> Wheel Alignment Made Simple