I’m getting frustrated with the belt vibration - any ideas to help?

[Wrongway]

The title sums it up. I have a 2015 RT SE6 which I bought in April and have put 5,000 miles on it so far.
Since buying it I avoided the freeways because of the harsh belt vibration starting around 60mph and up to 75 mph. I don’t have a krikit tension measuring tool and am in no way mechanically inclined so I rely on my dealer who I trust for any adjustments.
I had the dealer install a new rear tire 500 miles ago and here’s how it went with regards to belt vibration after the new rear tire was installed.
- belt vibration was close to the same as described above but now it started at 55 mph. The dealer had set the belt tension at 1050 newtons or 256 pounds with wheel on ground.

- I went back to the dealer and had the BRP Bulletin from 2015 with me. The lowest the dealer would set the tension was 900 newtons or 222 pounds with wheel on ground.

- I went back again and after talking with the service manager, they agreed to drop the belt tension to 730 newtons or 184 pounds with wheel on ground.

Now the vibration is still there but not nearly as harsh as it was. The STRANGE thing which I’ve never noticed before is that when cruising along at say 60 mph, when I let off the throttle I can feel belt vibration. This is happening at any cruising speed over 50 mph.
Your input is appreciated.

[K80Shooter]

.....
Now the vibration is still there but not nearly as harsh as it was. The STRANGE thing which I’ve never noticed before is that when cruising along at say 60 mph, when I let off the throttle I can feel belt vibration. This is happening at any cruising speed over 50 mph.
Your input is appreciated.

When you back off the throttle, the force on the belt is lessened as the engine is no longer pulling the rear wheel.
Applying throttle puts tension back on the belt so it is tighter.

[BajaRon]

186 is a bit low for a 2013+. 220-260 is the normal range on these bikes. 140-180 is what we set the 2008-2012 Spyders at. You aren't hurting anything at the lower setting. I'm just not sure going below 220 is helping you.

One thing that can happen is that running a new belt hard can stretchy it unevenly. These belts don't stretch much. But there is a seating in process of 50-100 miles where they need to be allowed to settle in without undue stress.

If you had a belt tension gauge. Here is what I would do. Measure tension. Spin the rear wheel 1/4 turn. Measure tension again. Do this 4 times and see if tension changes significantly. This will indicate an unevenly stretched belt, which cannot be corrected. At least this would identify or eliminate the belt itself, and not tension, as the reason for your vibration.

A quality belt vibration dampener is probably in your future.

[chipveres]

Second what Ron said. If nothing else, the damper will move the resonant frequency hopefully till it doesn't bother you.

[gkamer]

And ideas on where to get a quality belt dampener?

[ransman]

Smoothspyder

[gkamer]

Smoothspyder

All I see on their web site are back rests

[Peter Aawen]

All I see on their web site are back rests

Websites don't always tell the whole story!

Maybe you should try dropping Jim an email, his address is on the Smoothspyder logo on the Home page here; or there's a 'Contact Us' page on their site www.smoothspyder.com with both an email address and a phone number. If anyone knows if they still do make & or sell the SmoothSpyder Rotary Drive Belt Tensioners that gave them their name, I reckon he'll be the bloke to talk to!

Of course, you could also check out the Belt Dampeners on offer at Lamonster Garage. They have a pretty good rep for quality gear around here!

[fredgal]

https://www.lamonstergarage.com/belt...dler-pulley-1/

[honsfun]

Have you checked the drive pulley?? One of the symptoms is vibration as you throttle down and reduce tension on belt and pully. Recall??
'

[Wrongway]

Have you checked the drive pulley?? One of the symptoms is vibration as you throttle down and reduce tension on belt and pully. Recall??
'

Recall was done in April. It didn’t start the vibration while I throttle down until I reduced the belt tension to where it is which is 184 pounds with the rear wheel on the ground

[gkamer]

Websites don't always tell the whole story!

Maybe you should try dropping Jim an email, his address is on the Smoothspyder logo on the Home page here; or there's a 'Contact Us' page on their site www.smoothspyder.com with both an email address and a phone number. If anyone knows if they still do make & or sell the SmoothSpyder Rotary Drive Belt Tensioners that gave them their name, I reckon he'll be the bloke to talk to!

Of course, you could also check out the Belt Dampeners on offer at Lamonster Garage. They have a pretty good rep for quality gear around here!

Well I took your advice and emailed Jim. He replied back that they stopped making the dampeners back when Covid hit and parts were hard to come by. He didn't mention any plans to pick up production again.

[bigbadbrucie]

Recall was done in April. It didn’t start the vibration while I throttle down until I reduced the belt tension to where it is which is 184 pounds with the rear wheel on the ground

BajaRon suggested 220 - 260 for spyders 2013 or newer. Yours falls into that category, yet you seem to not listen to his advice. ?????

[BajaRon]

Have you checked the drive pulley?? One of the symptoms is vibration as you throttle down and reduce tension on belt and pully. Recall??
'

Throttling down does not reduce belt tension. It simply moves tension from the top side of the belt to the bottom side. And moves the slack from the bottom side to the top side. The OP's belt is too loose.

I have theories, but no real answer for why a lower tension gives better vibration control on the 2008-2012 Spyder. I do know the bearings can't take higher tension amounts and this is what drives that setting. These are very long belts. With length comes vibration. It can't be eliminated. But it can be managed.

[BLUEKNIGHT911]

BajaRon suggested 220 - 260 for spyders 2013 or newer. Yours falls into that category, yet you seem to not listen to his advice. ?????

From what others have said ..... ON-the-Ground KritKit measurements seem to be from 140 lbs to 160 lbs .... and this almost eliminates drive belt Vibes ..... JMHO .... Mike

[Wrongway]

Thanks to everyone for your input. It’s appreciated. I’m basing by belt tension on the BRP bulletin issued in 2015.
I received a message from a member who has experimented with different belt tensions and currently has his tension set at 185 pounds. He added a LAmonster tensioner which removed all vibration and this has been successful for 30,000 miles.
I’m ordered the tensioner from LAmonster.

[Sarge707]

From what others have said ..... ON-the-Ground KritKit measurements seem to be from 140 lbs to 160 lbs .... and this almost eliminates drive belt Vibes ..... JMHO .... Mike

I remember when this sprocket stuff started 3-4 years ago there was a bulletin to lower my 2015 F3 and others(?) to about the 140-160 range. It was thought excess tension helped cause sprocket problems. When mine came back from sprocket job it was at spec -he said -180 on the ground. I got vibrations I'd never had before at 65 MPH. I lowered the tension to 130 in the air which changes to 150 on the ground and I'm vibration free till over 75 - I rarely go there. I'm happy without a tension thingy.
Krikit gauge!

[askitee]

Bit late to this, but my '17 TRL was bad for belt vibration. I fitted a dampener and it made a major difference