Any ideas on what could cause headshake all the sudden? I had the bike parked for about 3 months or so. I took it out the other day and as soon as I got up into 4th and 5th it started in with a violent headshake. I mean nerve wracking bad. It only does it in softer stuff. On road and hard pack it is fine. I never had this problem before I parked the bike and have not changed anything as far as suspension goes.