Belt Tensioner - why

[JimH]

Hi Spyderfolks:
I have been trying to search and find out more about a belt tensioner and why or if they are needed by everyone. Should everyone have one on their machine, or how would you know if you need one?
I am trying to find out more in general about the reason for these and to recognize when would be needed.
Thanks in advance for sharing your knowledge,
Jim

[canamjhb]

What is commonly referred to as a "belt tensioner" is actually a damper. Its purpose is to reduce or eliminate harmonic belt vibration. If the belt tension is set to factory specs most will get a noticeable vibration at highway speeds especially when under a load. Reducing the tension of the belt is a good and accepted way to get rid of the vibration..... Jim

[Mazo EMS2]

Many Spyders have a vibration around 60-70 mph that is caused by the drive belt vibrating. The belt is pretty darn long and leaves opportunity for a vibration that resonates through various areas on the bike. Everyone is a little different, some have none at all. The best solution is to get real finicky with the belt tension. If you can get the tension dialed in perfectly, you can eliminate the vibration, but it's a tedious task and requires patience and usually several adjustments. There are MANY threads related to belt tension if you choose to search them out, and there are of course a lot of different opinions and solutions. Because of the daunting task of finding that sweet spot for belt tension, a few folks have engineered the various styles of "tensioners" available now days. The tensioner is merely a short cut to eliminate most and sometimes all belt vibration. A bit pricey for what they are, but effective. I was able to eliminate nearly all vibration, but I had it in my head (like a bad song) and from that point on I wanted it ALL gone.....so, I too installed a tensioner. Before you buy one, ask yourself how much vibration you have, and can tolerate. If you're good with it, ride it and forget the tensioner ever existed. If you're being driven nuts by vibrations, check the belt tension first, and ask a dealer to check it....typically they're too tight from initial setup.

[missouriboy]

In my 115,000+ miles on two machines, I have never noticed the need for one. I'd say if you don't FEEL the need for one, from vibration, then you don't need it.

After all, if it were truly needed by every machine, wouldn't it be original equipment?

[BLUEKNIGHT911]

Many Spyders have a vibration around 60-70 mph that is caused by the drive belt vibrating. The belt is pretty darn long and leaves opportunity for a vibration that resonates through various areas on the bike. Everyone is a little different, some have none at all. The best solution is to get real finicky with the belt tension. If you can get the tension dialed in perfectly, you can eliminate the vibration, but it's a tedious task and requires patience and usually several adjustments. There are MANY threads related to belt tension if you choose to search them out, and there are of course a lot of different opinions and solutions. Because of the daunting task of finding that sweet spot for belt tension, a few folks have engineered the various styles of "tensioners" available now days. The tensioner is merely a short cut to eliminate most and sometimes all belt vibration. A bit pricey for what they are, but effective. I was able to eliminate nearly all vibration, but I had it in my head (like a bad song) and from that point on I wanted it ALL gone.....so, I too installed a tensioner. Before you buy one, ask yourself how much vibration you have, and can tolerate. If you're good with it, ride it and forget the tensioner ever existed. If you're being driven nuts by vibrations, check the belt tension first, and ask a dealer to check it....typically they're too tight from initial setup.

X's 5 ..... I Used a KritKit guage .... Because I have measured the difference between the wheel on-the-ground vs. wheel of-the-ground measurements ..... I use the ON -the ground number because it 's quicker and simpler and just as accurate ..... I like 160 lbs O-T-G, and I don't notice any vibes .... I t wasn't difficult to achieve this and I have had two rear tire changes ( using the re-move the shock bolt method ) and the 160lbs. re-mained the same ..... My main concern with ANY of the tension / dampers is that if it breaks , your belt can become TOAST in very short order...... None of the sellers of the dampers Guarantee that it won't happen and None that I know of will give you a FREE belt ( $325.00 ) if it does ruin it ..... I'm not trashing anyone here just reporting my view on this ..... ride safe - ride happy ..... Mike

[IdahoMtnSpyder]

In my 115,000+ miles on two machines, I have never noticed the need for one. I'd say if you don't FEEL the need for one, from vibration, then you don't need it.

After all, if it were truly needed by every machine, wouldn't it be original equipment?

An OEM belt tensioner quite likely would not solve vibrations across the board. There are several causes for the belt vibration, the primary ones being belt length (fixed) and belt tension (variable). Other factors are speed (very variable!), road surface (variable), acceleration/deceleration (variable), pulling force going up and down hills (variable), and I don't know what else. All but the first are controlled or influenced by the rider's way of riding. The first is the only one controlled by the factory. With that many variables involved I don't think you'll find a single set of parameters, like belt tension, that will work the same for any two riders.

[JimH]

Thanks for everyone for the excellent explanations and the time you took to provide them. Either I am clueless to the vibration or it is not happening to me. My worry was damage creating a failure while I was on the highway far from home. Thank you one and all.
Kind Regards,
Jim

[AeroPilot]

It depends on your machine, how your ride and what your level of OCD is regarding worrying or noticing vibrations, etc. On my 15 RT I have over 50,000 miles and noticed the vibration when on the interstates between 70 and 73 mph roughly but only when the load, and speed matched the belt harmonics. I prefer to ride the secondaries at 64-66 mph, But being a little obsessive, I got a Christmas present of Lamonsters vibration dampener and put it on this winter.

The wifes 16 F3T has never bothered her and she rides the interstate everyday on her commute in the summer. She would let me know if there was a problem!! We did have a new sprocket under warranty around 35,000 but that is a known issue mostly on the higher toothed F3.

Now my Obsessive Compulsive nature will have to focus on checking the pulley and bearing periodically for wear or looseness, but I feel that Lamont has a good product.

Trying to worry less and looking forward to Ryding More when we can get out again on Trips