What's the recommended Belt Tension?

[K80Shooter]

I have noticed that there's mention in a couple of threads about the drive belt tension being to high and some people found that lowering it gave better results.

When searching belt tension, belt alignment and drive belts they all list a whole lot of threads but mostly none covered this exactly or either I couldn't find it.

So what's the recommended tension? I see 190 mentioned a lot as standard but what works best? I'm trying to get rid of some belt whine/noise on my 2020 RT-L

Thanks :spyder2:

 

[MONK]

It should be in your owners manual. Both of my RTs (2018 and current 2021) have had a high speed vibration, both around 70+mph. I had the belt tension lowered on both. It didn't do anything on the 2018 so I added a harmonic vibration dampening device (aka belt tensioner). It solved the problem. When I lowered the tension on the 2021, all it did was move the vibration to a different speed. I added a belt tensioner to this one, too, which again solved the problem.

Others haven't had any vibration and others have been able to completely eliminate the vibration simply by lowering the belt tension.

 

[K80Shooter]

I did install the lamonster belt tensioner today and it made little to no difference that I could tell. That's why I thought I would lower the belt tension.

 

[BajaRon]

I did install the lamonster belt tensioner today and it made little to no difference that I could tell. That's why I thought I would lower the belt tension.

What is you current belt tension? Hard to say where you should go until you know where you are.

 

[ButterSmooth]

I feel like I'm setting myself up like a B-17 over Schweinfurt on Black Thursday, but I don't get good results with a KriKit. In all likely hood it's my technique, but the Krikit seems to be insensitive to change, and the readout is rather coarse.

I use a Snark musical instrument tuner to measure the belt (pluck) frequency. I validated the Snark accuracy with more sophisticated instruments and used the Gates formula for my belt. I tried my cell phone with the Gates and other apps, but the cell phone microphone can't sense the low frequencies required. These are the tensions I ended up with:

122# in the air at the loose spot
173# in the air at the tight spot
150# on the ground at the loose spot
193# on the ground at the tight spot
for an average tension of ~160#

With this setting there is a slight vibration at 70mph, and it was better at 180# average. (next time)

Also, measuring the tension at three wheel positions is critical, since there is considerable run-out in the rear sprocket.

 

[K80Shooter]

What is you current belt tension? Hard to say where you should go until you know where you are.

Using this (https://www.amazon.com/gp/product/B000CRDLZM/ref=ppx_yo_dt_b_asin_title_o06_s01?ie=UTF8&psc=1) it is at 190, thought I might back it off to 180 and try that.

I took this reading after the dealer checked the tension per my request.

 

[BLUEKNIGHT911]

I feel like I'm setting myself up like a B-17 over Schweinfurt on Black Thursday, but I don't get good results with a KriKit. In all likely hood it's my technique, but the Krikit seems to be insensitive to change, and the readout is rather coarse.

I use a Snark musical instrument tuner to measure the belt (pluck) frequency. I validated the Snark accuracy with more sophisticated instruments and used the Gates formula for my belt. I tried my cell phone with the Gates and other apps, but the cell phone microphone can't sense the low frequencies required. These are the tensions I ended up with:

122# in the air at the loose spot
173# in the air at the tight spot
150# on the ground at the loose spot
193# on the ground at the tight spot
for an average tension of ~160#

With this setting there is a slight vibration at 70mph, and it was better at 180# average. (next time)

Also, measuring the tension at three wheel positions is critical, since there is considerable run-out in the rear sprocket.

Using a KritKit or any other tool that can be used - you shouldn't be using a loose or tight spot .... the KritKit has to beused in the manner that tool is designed for ie. the middle of the belt any other spot is going to give a False reading .... I only check it with the wheel ON_THE_GROUND.... I use 160lbs. measured in the middle of the belt...... I have no vibes that I can feel ..... good luck .... Mike

 

[K80Shooter]

Using a KritKit or any other tool that can be used - you shouldn't be using a loose or tight spot .... the KritKit has to beused in the manner that tool is designed for ie. the middle of the belt any other spot is going to give a False reading .... I only check it with the wheel ON_THE_GROUND.... I use 160lbs. measured in the middle of the belt...... I have no vibes that I can feel ..... good luck .... Mike

I did check it with the wheel on the ground and also in the center of the belt, honestly I checked it in several places before I settled on the 190 reading from the middle of the belt. I have the side plastic off right now so now's the time I want to try this. I'll try the 160lbs 1st. :cheers:

 

[Doug44]

I added LaM idler kit and it so far has completely taken care of the issue. However I am under the impression that this is sort of a can of worms for some or most that never goes away. Seems to go along with owning a Spyder

 

[K80Shooter]

I think that I must have one that wont go away. I added the lamonster idler/tensioner....No help.

I lowered the tension of the belt.... No help.

I increased the tension of the belt.... No help

I have it at 160 now with the lamonster tensioner installed. (Measured it on the ground without the tensioner touching the belt) I'm going to button it back up and just ride it until someone say's the new (white) pulley helps or doesn't help. I'm also going to continue complaining to the dealer. They did tell me it would be replaced so we'll see but I doubt it.

 

[EdMat]

I think that I must have one that wont go away. I added the lamonster idler/tensioner....No help.

I lowered the tension of the belt.... No help.

I increased the tension of the belt.... No help

I have it at 160 now with the lamonster tensioner installed. (Measured it on the ground without the tensioner touching the belt) I'm going to button it back up and just ride it until someone say's the new (white) pulley helps or doesn't help. I'm also going to continue complaining to the dealer. They did tell me it would be replaced so we'll see but I doubt it.

Are you sure its not a tire problem you are feeling?

 

[K80Shooter]

Are you sure its not a tire problem you are feeling?

It's not what I feel, it's what I hear. There's several threads about it on here.

 

[ButterSmooth]

It's not what I feel, it's what I hear. There's several threads about it on here.

Is it the 49 ± 2mph whine? If so, that is the main thing the 'new' pulley fixes. My whine was quite bad, but it went almost completely away when I aligned my belt 3.5mm from the inner rear flange. That's right in the middle of the 2-5mm specified range. The other sound mine made was a 'Gronk' when taking off from a stop -- even worse if turning from a stop. The alignment fixed that completely. My belt has always been against the outer-front pulley flange -- no adjustment ever changed that.

I'll probably change to the new pulley in the near future. If I need to take it off for maintenance, there's no point in putting the 'old' one back on.

 

[K80Shooter]

Is it the 49 ± 2mph whine? If so, that is the main thing the 'new' pulley fixes. My whine was quite bad, but it went almost completely away when I aligned my belt 3.5mm from the inner rear flange. That's right in the middle of the 2-5mm specified range. The other sound mine made was a 'Gronk' when taking off from a stop -- even worse if turning from a stop. The alignment fixed that completely. My belt has always been against the outer-front pulley flange -- no adjustment ever changed that.

I'll probably change to the new pulley in the near future. If I need to take it off for maintenance, there's no point in putting the 'old' one back on.

That's it from about 46 to 52 or so it's pretty loud but any other speed it's livable, honestly I can live with it if I had to. I have moved the belt in and out but that doesn't help either. When I got it the belt was on the inside flange of both pully's, I moved it over but it went against the outside front pully then. I've moved it back a little and the belt is maybe a 1/8" from the inside of the rear pully and I can get a business card between the outer flange of the front pully. In my opinion the front pully should have been a little wider.

 

[Bangorbob]

Most people make it sound very easy to set the belt tension. I guess I am missing something. Please correct me, but you have to lossen the axle nuts-correct? Aren't they torqued at over 200 ft lbs?

 

[Possible]

166 lb.ft. I believe. Not too big of a deal, but you do need a long breaker bar to loosen, and a 200+ lb.ft. torque wrench to retighten them.

 

[ButterSmooth]

Most people make it sound very easy to set the belt tension. I guess I am missing something. Please correct me, but you have to lossen the axle nuts-correct? Aren't they torqued at over 200 ft lbs?

166'#. I don't know how easy it is for other folks, but it's a fiddly adjustment for me. The single biggest problem for me is that the belt moves toward the inner rear flange when the axle torque is increased from 90'# to 166'#. The adjusters are under tension and never loosen and everything is locked in position at 90'#. But when the final torque is applied the belt moves inboard about 1/4". The last time I did it, at 90'# it ran at the outer edge of the sprocket, then moved in when torqued to mid-spec, 3.5mm. Repeated tightening to 166'# can be exhausting for an old man.

I also noted in the parts diagram that the axle nut is a one use item. You'd need a pile of them if it had to be replaced for each tightening.

 

[Possible]

Somehow I doubt that everyone replaces them every time.

 

[Jetfixer]

166'#. I don't know how easy it is for other folks, but it's a fiddly adjustment for me. The single biggest problem for me is that the belt moves toward the inner rear flange when the axle torque is increased from 90'# to 166'#. The adjusters are under tension and never loosen and everything is locked in position at 90'#. But when the final torque is applied the belt moves inboard about 1/4". The last time I did it, at 90'# it ran at the outer edge of the sprocket, then moved in when torqued to mid-spec, 3.5mm. Repeated tightening to 166'# can be exhausting for an old man.

I also noted in the parts diagram that the axle nut is a one use item. You'd need a pile of them if it had to be replaced for each tightening.

It can be a very tedious process, but after adjusting the tension, try lowering the bike to the floor before you tighten the axle nut to final torque. This will generally prevent the shift you are getting by allowing the geometry of the swingarm and the weight of the bike to keep both tensioners loaded. If you apply final torque with the wheel in the air, you are putting in enough twist to move one side slightly off the tensioner which is why you then see the belt move. If you got the tension set right, you're done. If you still need to adjust it, then it's back up & down on the jack some more!

 

[BLUEKNIGHT911]

166'#. I don't know how easy it is for other folks, but it's a fiddly adjustment for me. The single biggest problem for me is that the belt moves toward the inner rear flange when the axle torque is increased from 90'# to 166'#. The adjusters are under tension and never loosen and everything is locked in position at 90'#. But when the final torque is applied the belt moves inboard about 1/4". The last time I did it, at 90'# it ran at the outer edge of the sprocket, then moved in when torqued to mid-spec, 3.5mm. Repeated tightening to 166'# can be exhausting for an old man.

I also noted in the parts diagram that the axle nut is a one use item. You'd need a pile of them if it had to be replaced for each tightening.

Those " so-called " ONE USE nuts are called that because of ..... LAWYERS .... I have been re-using, " one-use " nuts for Decades and never had a problem. Have you noticed in your Owners manual, that BRP says you should bring your Spyder IMMEDIATELY to your nearest Dealer if you have any problems ...... do you ????? ................... good luck ... Mike :thumbup: