Belt Tensioner

[I-Day]

I bought a 2016 F3T in March and have a big trip coming soon. My belt starts to vibrate at about 70 mph which is the speed I like to cruise at. I talked to my dealer about putting on a belt tensioner and he recommended tightening my belt a bit which should move that vibration out of my sweet spot. Does this work?

[Road-Kill]

I don't know about tightening the belt but an idler works. I have the BRP idler with over 9000 trouble free miles on it but there is a HUGE discussion going on in another thread about upgrading BRPs idler to two bearings or buy Docs. This will be a never ending topic until BRP offers a more resilient solution. My thoughts.

[PW2013STL]

I don't know about tightening the belt but an idler works. I have the BRP idler with over 9000 trouble free miles on it but there is a HUGE discussion going on in another thread about upgrading BRPs idler to two bearings or buy Docs. This will be a never ending topic until BRP offers a more resilient solution. My thoughts.

Mine had close to 12,000 miles on it before it started it's swan song. The two bearing set up I am puting in should fix that. Now if I did not already own the BRP one I would have purchased Doc's.

[I-Day]

Does anyone have Doc's phone number?

[PW2013STL]

Does anyone have Doc's phone number?

Go here-

http://dochumphreys.wixsite.com/roadster

Les

[I-Day]

Well I just read all the posts on the other thread called Belt Tensioners and am more confused now than ever! I spent 26K for my ride and shouldn't have to pay another penny to eliminate belt vibration. It amazes me how BRP just ignored this and doesn't fix it under recall! At this point I think I'll just live with the vibration cause I don't want to spend another $265 plus the installation and still have a problem!

[Bensonic]

I don't know about tightening the belt but an idler works. I have the BRP idler with over 9000 trouble free miles on it but there is a HUGE discussion going on in another thread about upgrading BRPs idler to two bearings or buy Docs. This will be a never ending topic until BRP offers a more resilient solution. My thoughts.

I watched a you tube video on installing this. It shows it mounted on the top side of the belt. How does this help with belt vibration being on the top?
If it does, great, I will probably get one. Just wondering.
thanks

[Roadster Renovations]

I watched a you tube video on installing this. It shows it mounted on the top side of the belt. How does this help with belt vibration being on the top?
If it does, great, I will probably get one. Just wondering.
thanks

The top of the belt is like a guitar string vibrating and the damper is like pressing a finger on it and stopping it.

[PinkRosePetal]

The top of the belt is like a guitar string vibrating and the damper is like pressing a finger on it and stopping it.

Whilst that is true, a tensioned string (belt) will not vibrate on its own, it has to be energised buy some force. In this sense a roller as a damper is a band-aid because it's not dealing with the actual cause of the problem. It's notable that a good many Spyders do not suffer from the vibration, it seems that they do not have the energising force transmitted to the belt sufficiently to cause it to resonate.

My experience, and from what i've read, many others' experience, is that the resonance occurs when the engine applies power as it does when on cruise control when it modulates the throttle. Under these conditions the belt will undergo extra tension applied by the belt driving torque applied at the engine pulley and it seems that engine vibration is the force energising the resonance of the belt. Perhaps some engines are not as smooth in operation as others or perhaps there are engine mounting issues which don't absorb this excitation energy. BRP would do well to get on top of the real issue IMHO.

[4 MARIE]

NO it doesn't,and it may accelerate bearing wear.

What it DOES do is change the "frequency" of the harmonic, but not when it arrives.

Get the Doc Humphrey's tensioner setup. It surely is the superior set up.

[Bob Denman]

Get the one from Doc Humphreys!

[Bruiser37]

I bought a 2016 F3T in March and have a big trip coming soon. My belt starts to vibrate at about 70 mph which is the speed I like to cruise at. I talked to my dealer about putting on a belt tensioner and he recommended tightening my belt a bit which should move that vibration out of my sweet spot. Does this work?

Answer from Can Am customer service regarding their OEM belt damper accessory... didn't even mention their OEM damper... wonder why? Next to last paragraph answers all and any questions directed to customer service. Give em a call and confirm you have a problem. Enjoy the free vibration massage while riding in belt vibration range. BTW feel free to refer to case number. She is an erudite BRP guru... you can tell by her answer to belt vibration issue.

"Good day Mr. A*****,

Thank you for taking the time to contact BRP.

In response to your request regarding the vibration on your F3 Spyder, please note that the Spyder drive belt is a tensioned string system that transmits the drive pinion torque to the rear sprocket via the tension of the upper part of the belt.

The natural response of a string system is to vibrate when stretched and released at different speeds and strengths. The accumulated energy of these movements in the belt will be dissipated throughout the entire vehicle through the drive pinion and the rear sprocket.

We suggest you contact your local BRP dealership, they might be able to adjust your belt to displace the vibration, but it will not eliminate it as it is normal for a belt-driven vehicle to vibrate.

Should you have any other questions or comments, do not hesitate to reach us by replying to this email or call us at 1-888-272-9222.

Once again, thank you for contacting BRP.


Sandra B.
Customer Service Representative

ref:_00D301Fh2R._5000c1NDMpo:ref"

[007james]

ALL Belt Dampeners are Placebos, in my opinion, after 7500 miles of " Tweeking" tests on my 2016 RT Limited. Belts flex, stretch, expansion, contraction, under different loads, such as acceleration, deceleration, different speeds, wind velocity with Wind Screen up or down, up hill, or down hill, and tires wearing, changing the original balancing! Sorry, but there are no permement " Fixes" to eliminate Belt Chatter Vibration completely on these Spyders with long belts, as BRP Customer Service Rep. confesses! Drive shafts work well on motorcycles, but they are much shorter lenghts. If they were long, like on Soyders, then even the Drive Shafts would need to be balenced, and the Differential Gears would also need balancing and service. So, for those of us who are too old to handle Two Wheelers, then we either have to accept the Vibration factors, or,.........buy a Motorized Wheel Chair. ( Personally, that option is on hold for me. ) I had a BRP new 1973 Three Cylinder Free Air Two Cycle Snowmobile that ran like a Raped Ape, but was belt driven. The Vibration over 50 MPH was massive, even way back then, but it was the fastest Machine money could buy at that time. No one minded the Vibration when they could get that high speed. But, if "Some One" comes out with a conversion kit that totally eliminates the belt vibration, COMPLETELY, on my Spyder, for $500 or less, and instals it under Guarantee, I will be one of the fiirst in line to purchase. BRP will never change from their Belt driven system. They will keep passing the buck to the Dealers who will keep BSing the new owners unfamiliar with the problem. It is not a Safety problem, so BRP don't need to address it any more than they already have, by their Plastic Dampener device.

Answer from Can Am customer service regarding their OEM belt damper accessory... didn't even mention their OEM damper... wonder why? Next to last paragraph answers all and any questions directed to customer service. Give em a call and confirm you have a problem. Enjoy the free vibration massage while riding in belt vibration range. BTW feel free to refer to case number. She is an erudite BRP guru... you can tell by her answer to belt vibration issue.

"Good day Mr. A*****,

Thank you for taking the time to contact BRP.

In response to your request regarding the vibration on your F3 Spyder, please note that the Spyder drive belt is a tensioned string system that transmits the drive pinion torque to the rear sprocket via the tension of the upper part of the belt.

The natural response of a string system is to vibrate when stretched and released at different speeds and strengths. The accumulated energy of these movements in the belt will be dissipated throughout the entire vehicle through the drive pinion and the rear sprocket.

We suggest you contact your local BRP dealership, they might be able to adjust your belt to displace the vibration, but it will not eliminate it as it is normal for a belt-driven vehicle to vibrate.

Should you have any other questions or comments, do not hesitate to reach us by replying to this email or call us at 1-888-272-9222.

Once again, thank you for contacting BRP.


Sandra B.
Customer Service Representative

ref:_00D301Fh2R._5000c1NDMpo:ref"

[Dmetcalf]

I just don't understand why these machines need a belt tensioner at all .! If Harley has the same final drive system with no vibration then is there an engineering issue here ..??!
Sorry for the rant, but really why is there an issue with this on these very pricey machines..?
BRP want to chime in here ..?
Thanks for allowing me to express my opinion here .!

[SPYD1]

Engineering. It needs a tensioner.

[mikeytheb]

I just don't understand why these machines need a belt tensioner at all .! If Harley has the same final drive system with no vibration then is there an engineering issue here ..??!
Sorry for the rant, but really why is there an issue with this on these very pricey machines..?
BRP want to chime in here ..?
Thanks for allowing me to express my opinion here .!

There are dozens of hits when you google Harley Drive Belt Vibration - it's a problem but the engines on those shake so bad most people don't notice the belt vibration.

[ofdave]

There are dozens of hits when you google Harley Drive Belt Vibration - it's a problem but the engines on those shake so bad most people don't notice the belt vibration.

another Harley myth.
The engines that shake at idle are those that are rubber mounted. The solid mounted engines do not shake.
The shaking goes away at riding speeds.
Being a V-twin, they have inherent vibration that inline or flat engines do not have.

[IdahoMtnSpyder]

I just don't understand why these machines need a belt tensioner at all .! If Harley has the same final drive system with no vibration then is there an engineering issue here ..??!

Here are a couple of comments from a Gates publication from back in 1993. ww2.gates.com/IF/facts/documents/Gf000280.pdf

Q. What causes belt-drive vibration and how can it be corrected?
A. Drive belts experience both vertical and lateral vibrations when their natural frequencies coincide with resonant
frequency of connected equipment.
Belt tension can affect the amplitude of this vibration. Therefore, to correct the problem, first check for proper
tension. A common method to control vertical vibration uses a restraining device (metal rod or idler pulley) placed
perpendicular to the belt span and close to or lightly touching the belt. This device should be positioned roughly
1/3 of the span distance from the larger pulley.
If this does not work, consider changing other drive parameters to reduce the amplitude of vibration or alter its
frequency. Such parameters include span length, belt type, misalignment, inertia of driving or driven machinery,
pulley diameter and weight (inertia), speed, and the number of belts. In some cases (where original unit was
oversized), it may be possible to downsize the drive by reducing the number of belts or belt width, and increasing
the static tension to alter the belt’s natural frequency so it doesn’t coincide with the excitation frequency of the
machinery. When it can be done safely, it is preferable to reduce the static tension to keep the operating belt tension
below the belt’s natural frequency range.

Q. What is the proper procedure for tensioning a drive?
A. First, consider another question: Why is proper tension necessary? V-belts use friction between the belt
sidewalls and sides of the sheave to transmit power. By contrast, synchronous belts use the engagement of teeth to
transmit power.
Over-tensioning either a V-belt or synchronous belt causes excessive bearing load, reduced belt life, and excessive
pulley wear. Under-tensioning a V-belt causes belt slippage, whereas under-tensioning a synchronous belt can lead
to severe tooth wear and even ratcheting (jumping teeth).

Doc has gotten it right it looks like, lightly at 1/3 of the span.

Mike, you might be interested in noting the last sentence in the quote above.

[GaryinWI]

The belt on the Spyders is twice as long as on a Harley or other belt-Drive bikes. That’s why they need an idler/tensioner.

[JimSter]

I just received a Gates 91132 Krikit II Drive Belt Tension Gauge from BajahRon's to check the tension on my F3 drive belt.
It tells me that I have 200#'s of tension on the belt.
However I'm getting the vibrations when letting up on the trottle.

Now the belt tensioner will supposedly eliminate the vibrations even though the belt is that tight?


Thanks much, guys, JimSTer

[canamjhb]

Easiest thing to do is reduce belt tension. Yours is way too tight. TST61y014s05 suggests the tension on an F3 be set at 300N +/-100. I would adjust your belt before adding a damper...... Jim

[JimSter]

Hello canamjhb:

Thanks so much for your input. You've solidified my thoughts that I need to loosen the belt tension some.
However my tool measures in pounds. So can you translate 300N +/-100 for me?
I saw 160-180 pounds somewhere on here.

Thanks again, JimSTer

[ssmcclub]

My new 2019 special series can am spyder came with belt tensioner from the factory I guess they released that it needed one

[h0gr1der]

Hello canamjhb:

Thanks so much for your input. You've solidified my thoughts that I need to loosen the belt tension some.
However my tool measures in pounds. So can you translate 300N +/-100 for me?
I saw 160-180 pounds somewhere on here.

Thanks again, JimSTer

300 ±100= 200-400N

200 N= 45 Lbs (rounded)

400N= 90 Lbs (rounded)

[Revalden]

I put the BRP tensioner on my RT and on first ride with it installed I heard a clicking sound. So, went home to pull the Tupperware and have a look. And right next to the pulley in the belt is A DAMN PEBBLE STICKING UP THRU THE BELT!! Spyder God looking out for me? I haven't ridden it since I found it. I need to wait until next month's payday to buy a new belt. I just hope it hasn't affected either sprocket.