I have the same bike, and I notice a little shaking(wobble) at that speed, also...I had my front tire re-balanced, and it is not as noticeble......but it does not Violently Shake, as you say yours does....Have the forks checked, tires rebalanced, and proper tire pressure........I love my bike..I logged 6000kms on one trip alone last season, with a blown signal light being the only casualty..