Burning Smell - New Belt Tensioner

Around 150 miles ago I put on a new belt tensioner (2021 Spyder RT-L) and removed the OEM/stock one. I had a vibration around 45 to 50 MPH and it was really bothering me. So - new tensioner is on, I was very careful to follow the directions and align it, etc. Vibration/Harmonic is now gone but I have a bit of a burning smell coming off the bike. I wrote the company (Lamonster) but haven't heard back yet - just wanted to see if anybody else has experienced this?

I'm going to swap out the new one and go back to the original to see if the smell goes away (and of course if the harmonic comes back).

Thanks - Tom

Check your belt first to see if it's running up against one of the sprocket flanges.

Hey There,
We installed after market tensioners as there were none installed from the factory (we both ride 2020 RT's). We both could smell a "burning" scent after a ride, turned out to be manufacture labels attached to the catalytic converter and exhaust manifold. There is no indication of excessive heat or friction from the drive belt or belt tensioner (I set the tension), we monitored it closely as we were concerned too. Even after 4k miles, we still can smell a bit of that burnt rubber odor, but the belt and tensioner are cool to the touch and have had no failures.

I would just go out and take a good ride get down and check for heat on the roller set up and heat on the belt, if there's no heat there and your belt is at the right tension and aliened, drive on. The thing about these tensioners is that you have a small wheel with small bearings in there going VERY fast and it's just a matter of time when it will go, and if you do not check them on a regular basis, they can take your belt out! So, you are faced with, do I put up with a small vibration, or watch and check out my tensioner on a regular basis. I do not use one, but you have rubber on rubber there and maybe after a few heat cycles it will go away. Good Luck, check it for heat after a good ride!!!:dontknow:

Thank you all for your suggestions - I'll check it out and report back with anything I find.

A quick update on my issue: At first I thought maybe my belt was out of alignment as it was up against the inside of the rear sprocket. I had checked it while it was parked in the garage, but then figured out that when I'm driving, the belt is fine. I back the bike into the garage and when I do that, the belt shifts up against the sprocket. When I'm riding, it's off of the sprocket and not rubbing at all. Took it for a 20 mile ride and stopped to check the belt - almost no heat at all, so I think the belt is okay.

I removed the Lamonster Belt Tensioner and replaced it with OEM one and the burning smell drastically went down - almost nothing at all. I had checked the cat and it was pretty clean, but I gave it a good wipedown anyway.

So - here I am, back to my OEM tensioner, belt alignment is fine and the burning smell is gone. I guess I'll leave it as it is and sell the Lamonster tensioner, and I don't feel like going to the motions of putting it back on.

Appreciate all of the input on this - thanks!

It is most unusual not to hear back from Lamonster, tpc. They are very customer focused. If there was an inherent issue with their tensioner it wouldn’t be selling. Try giving them a call, as it would be well worthwhile finding the root cause of your issue. It could well be a faulty component in the tensioner (which Lamonster will make good), or it could be completely unrelated. The Lamonster tensioner is far more strongly made than the BRP one, and will last a considerably longer period.

Pete

Thanks Pete - I did finally hear from them and spoke to one of their technicians. He basically said to check the belt alignment and also to check the cat to see if there was debris on there. I'm definitely not saying it's their tensioner, just that the burning smell has basically gone away by removing it. it's a lot of effort to keep diagnosing this and I am at the point where it's time to ride, so we'll see how it goes and I'll make a decision later in the year about putting it back on or leaving it as is (or as Mikey said above, maybe just going with no tensioner at all).

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Originally Posted by tpc66

Thanks Pete - I did finally hear from them and spoke to one of their technicians. He basically said to check the belt alignment and also to check the cat to see if there was debris on there. I'm definitely not saying it's their tensioner, just that the burning smell has basically gone away by removing it. it's a lot of effort to keep diagnosing this and I am at the point where it's time to ride, so we'll see how it goes and I'll make a decision later in the year about putting it back on or leaving it as is (or as Mikey said above, maybe just going with no tensioner at all).

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Yes, I understand that reasoning completely, tpc. I’m in two minds whether to remove the BRP tensioner from my ‘21 and run it naked like Mikey……..actually, I have just decided that is what I will do, as you see quite a few reports of the BRP tensioner failing and causing issues. If I get vibration that bothers me, I’ll be contacting Lamonster for their tensioner:thumbup:

Pete

My 2021 RTL has the stock BRP belt tensioner as it was factory installed. It is still seemingly OK at 8500 miles...but I have a new Lamonster tensioner assembly on the shelf and will replace the factory tensioner with the Lamonster version if I ever get the time to replace the worn out OEM rear tire with the new Vredistein Quatrac, but working 50+ hours a week gets in the way so the Spyder is last on the list.

The Lamonster tensioner is VASTLY better made in all aspects than the OEM tensioner.

1.) much better roller tension arm (machined aluminum) and steel, adjustable mounting bracket
2.) Precision ball bearing pivot for the roller tension arm
3.) Larger diameter roller (less rpm) with double (two)ball bearings on roller vs a single bearing stock

While anything can and will wear and/or fail, the Lamonster unit is of much higher quality. The bearing and roller, with it's two bearing and the larger diameter, roller should be more durable than the smaller stock roller, plus it is mounted on a precision pivot arm versus a plastic arm.

The new unit will be installed when I get the chance to replace the tires and I will listen for any unexpected sounds and pay attention to any unexpected burning smells as well.

Thanks,
Rod

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Originally Posted by tpc66

Thanks Pete - I did finally hear from them and spoke to one of their technicians. He basically said to check the belt alignment and also to check the cat to see if there was debris on there. I'm definitely not saying it's their tensioner, just that the burning smell has basically gone away by removing it. it's a lot of effort to keep diagnosing this and I am at the point where it's time to ride, so we'll see how it goes and I'll make a decision later in the year about putting it back on or leaving it as is (or as Mikey said above, maybe just going with no tensioner at all).

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Have you ever tried to ride it without one on your bike at all? Just for kicks try it and see how it feels for you. You may find that this vibration everyone's talking about isn't that bad, and you could just go without. My Dad had a old HD Electro Glide when I was growing up, now I want to tell ya, that's a vibration I would not live with, I have ticklish feet so you can imagine what I was going thru. Good like, Ride more, worry less.

My '14 had a bit of a vibe to it at certain speeds. Didn't really bother me much, but I was ordering some stuff from Lamonster and they had the tensioner on sale. I smoothed things out even more and I'm glad I got it.

When I had a Lamonster belt tensioner on my 17 F3 LTD, It was made of plastic . It looked good but I thought the plastic one could Flex side to side on the belt. I am glad to hear it is metal now.

I know I am :bdh: here. And I should give up. But...

This is a Belt Tensioner (one on each side at the back of the swingarm)


This is a Belt Vibration Dampener


While the vibration dampener does technically add tension to the belt. It is an insignificant amount. Belt tension and belt alignment are controlled by the tensioners at the back of the swingarm.

Love it! "Belt tension and belt alignment are controlled by the tensioners at the back of the swingarm." So easy to miss the obvious when deeply involved in a serious discussion. LOL

When they did my sprocket recall the tech left my Lamonster tensioner hanging straight down and not up of the belt. I reached in and was able to twist/flex the belt enough to put the roller back up on the belt. I say this because it is an easy way to bypass the tensioner for testing or in a case of a failure of the roller bearings.

If you check belt tension with the vibration dampener engaged and not engaged, you will find virtually no difference at all. Which means you don't need to disengage the vibration dampener when checking belt tension. It makes no difference.

I put a LaMonster belt tensioner on my new 22 RTL I had 250 miles on it when I swapped the tensioner and like you said I noticed a burning smell for a bit. I just got back from a 450 mile ride and the smell has gone away,

I thought I'd post an update on this since it's been a while. I tried all combinations to see what would work for both the burning smell and for the vibration: 1. OEM Tensioner; 2. Lamonster Tensioner; 3. No Tensioner. The results are that the vibration definitely is reduced with the Lamonster over the OEM, and is more noticeable with no tensioner at all; The smell is definitely not because of any of the belt tensioners - I believe it was just debris that had collected on top of the cat. I gave it a good cleaning and it's pretty much gone away (although it's still slightly there, but then again it's pretty hard to clean that cat off without dropping it).

So - in the end I put the Lamonster back on since it is definitely a very high quality item, I have a newer helmet that is better insulated (and therefore that vibration noise is reduced), and I will keep the cat cleaned on a regular basis to reduce any burning smell.

I appreciate everyone and your input - thanks and have a Happy Easter!