Demosemorris vibration/rattle question

Hey everybody.  I was wondering if anyone has encountered this problem.  2004 Silverwing with new-ish drive belt.  When I accelerate from stop on level pavement--no real issues.  When I accelerate up a hill, or when riding two-up I get a nasty vibration/rattle at around 3500 rpm.  If I give it more throttle, it goes away.  Any ideas?

1st welcome aboard 2nd it seems to be the nature of the beast, loose body panel would be one area to check.

It sounds like belt slap. At certain load and speed the belt vibrates like guitar string and slaps the CVT outer casing.

It's considered normal and many members experience it. Newer belt and CVT cleaning seem to reduce it but not considered mandatory.

Thanks to both of you. I think the belt slap is probably what is causing the noise so I will take off the CVT cover and have a look. It is also clear that various plastic components have shrunk or whatever they do to rattle at various rpms. That little "push here to open" glovebox on the right side is especially prone to it. Anyone tried to replace one of those?

That right side glove box has one screw at the front edge. Some people never noticed it was missing. Adding it back may help with your rattle noise if yours is missing.

When you open up the CVT case look for shiny parts in the middle of the case both at the top and bottom on the inside. That's tell tale sign that your noise was the belt slap.

Will do. Thanks.

The glove box door rattle can be reduce by putting something squishy in the hinge area so there is a bit more spring open force against the latch. I had a short section of screen edge tube in there but a small piece of foam rubber would do the trick.

Windshield screws like to loosen up too. It's hard to determine exact issue but seems most SW's do vibrate just look in mirrors they also do it .

I deduced the the intermittent rattle on the Crowman was a loose bit of the wiring harness flapping against the body.

It's all meant to rattle. If it stops rattling it means something has fell off!

Seriously don't worry about it. The transmission is a collection of weights, springs and a rubber belt and the fairing acts like a huge resonator at certain revs - it's the nature of the beast to rattle and buzz.

For what it's worth I too noticed the belt slap noise on my Wing and with 4,000 miles on the odometer, replaced the original belt anyway. Also cleaned and lightly oiled(with dry lubricant) the variator and the sliders(26gram Dr Pulley). This eliminated most of the slap noise and the bike drives smoother.(less lurching feel at slow speeds)

To me it was worth the cost and effort.