I've been following Vince's post and noticed the last 2 times I've had the Sportman out above 50 mph that I have had similar issues. The most resent time was this morning while taking the country roads to my father in-laws. The shake is more of a pulsating shake every couple seconds for a second. I would think if the tires were out of balance or the rims out of round it would be more of a constant vibration. All of the studs are tight and I gave both wheels a tug and they seem ok. The shake is bad enough that you can see the fenders shake right along.

Make sure the arm on your steering box is tight as well.

Thanks for following me Jim, I havent driven mine in a few days since the wife is out of town have no one to tow me if I break down still working the bugs out of this thing. If you look at the dash above the steering wheel you just see it but I still need to do some more investigateing on this I hope I can find a means to the end to make driveing more enjoying. V