Join Date: Feb 2010
Location: Blackwood, NJ, USA
Re: Severe Shake at Exactly 45 mph
First welcome to the LT community with your bike. When I bought my LT several years ago, I did the same thing...took my hands off the grips to test how straight th bike would go...since I took my hands off the grips, the bike decelerated. This was when I got the violent shaking -- it seems prevalent when the bike decelerates. And yes, it did not happen to any other bike I rode.
Shortly after this happening, and not for the reason of the shaking, I replaced my tires as the bike had about 9000 miles on the original tires -- the front tire was badly cupped and the rear was close to needing replacement. By the way, I never took my hands off the grips to test if the new tires cured this issue.
Here is what I found out since that time...big bikes like the LT, including the Goldwing, experience this phenomenon due to their weight and geometry. Although it doesn't happen to all LTs, it is normal and you should not worry; there seems to be no permanent fixes to this issue.
If your tires need replacement, get the replaced -- I added Dyna Beads to my tires. I will tell you this was the single most impressive thing I did to the bike. Not only did the bike handle better by a factor of 50%, the ride was soooo much quieter.
I hope this helps and what you learned is that you don't take your hands off the grips -- especially when coasting and the bike decelerates.