'21 F3 belt tensioner - why is it on top?

[Hoginedgewood]

So I finally crawled around the f3s. It’s got a tensioner on the top of the belt. If I’m reading correctly this wheel won’t last long? I’m wondering why it’s on the top, seems like the top would be tight when accelerating, in some older HD applications guys will put a skate wheel on the bottom of the chain. This wheel on the top is throwing me.

 

[Spyderman2018]

It's mounted on top because that's the easiest place to put it, out of harm's way. If it was mounted on the bottom of the frame, any road debris that you couldn't avoid may kick up from the front tires may damage it/ tear it off.

 

[Peter Aawen]

Another thing - they aren't actually 'belt tensioners' - they are 'vibration dampeners'! So they need to be where the vibrations are occurring... juuuust resting lightly on the tight part of the belt to dampen out the harmonic vibrations that occur on some at specific speeds! :thumbup:

 

[ButterSmooth]

So I finally crawled around the f3s. It’s got a tensioner on the top of the belt. If I’m reading correctly this wheel won’t last long? I’m wondering why it’s on the top, seems like the top would be tight when accelerating, in some older HD applications guys will put a skate wheel on the bottom of the chain. This wheel on the top is throwing me.

It's throwing you because you're thinking of it as a 'tensioner' and it's not -- it's a vibration damper. A 'tensioner', like you have on your car's serpentine belt, does apply the basic tension to the serpentine belt. The Sypders belt is tensioned by the basic 'tension and alignment' adjustment at the rear wheel. The top 'driving' run of the Spyder belt has resonant frequencies (depending on load, speed, tension and belt dimensions) and that's the source of the vibrations we feel. The damper helps 'quiet' these vibrations. The basic tension of the belt can be adjusted to move the resonant frequency to a speed that isn't in the normal driving speed range, but that's tricky, because you don't want the tension too high, endangering bearings and such.

 

[Rattlebars]

For info on setting your belt tension and alignment. I'm guilty as charged for calling it a belt tensioner and not a vibration damper but technically it's called an IDLER.

 

[Hoginedgewood]

Guilty as charged. I knew it wasn’t a tensioner.

 

[BajaRon]

So I finally crawled around the f3s. It’s got a tensioner on the top of the belt. If I’m reading correctly this wheel won’t last long? I’m wondering why it’s on the top, seems like the top would be tight when accelerating, in some older HD applications guys will put a skate wheel on the bottom of the chain. This wheel on the top is throwing me.

It is mounted on top because first of all, it is not a belt tensioner. It is a vibration dampener. A very different thing. These actually change the belt tension a very small amount. Not enough to make any difference in belt tension. 2nd, because it is the tension side (top) which creates the vibration you feel, not the slack side. Seems counter-intuitive. But that is why it is on top.

Edit Note: Oops! I didn't read the other replies first. Therefore, mine is redundant. I'd delete it if I could. But I can't. So, an apology is my best alternative.

 

[Hoginedgewood]

For info on setting your belt tension and alignment. I'm guilty as charged for calling it a belt tensioner and not a vibration damper but technically it's called an IDLER.

View attachment 189573

I don't think you would catch me adjusting the belt while the wheel is spinning, im a whimp.

 

[bikerchris1270]

So I finally crawled around the f3s. It’s got a tensioner on the top of the belt. If I’m reading correctly this wheel won’t last long? I’m wondering why it’s on the top, seems like the top would be tight when accelerating, in some older HD applications guys will put a skate wheel on the bottom of the chain. This wheel on the top is throwing me.

Since Can Am is installing their belt dampeners as standard equipment due to “popular demand”……It got me thinking just how much influence this forum and LaMonster sales contributed to their decision. It’s nice to have this forum to share our experiences and questions.

 

[Rattlebars]

Since Can Am is installing their belt dampeners as standard equipment due to “popular demand”……It got me thinking just how much influence this forum and LaMonster sales contributed to their decision. It’s nice to have this forum to share our experiences and questions.

not all models last I checked.

I don't think you would catch me adjusting the belt while the wheel is spinning, im a whimp.

Well, like the bloke says, "Go to the dealer and empty your wallet!"

 

[RICZ]

I got myself a very good belt tension and alignment without turning the engine on. I kept rotating and checking.

 

[askitee]

We are on the same page. I worked as a mechanical fitter for 17 years at a 2000 Megwatt Coal Fired Power Station. Some plant that was belt driven, (Ash Crushers, fans etc) would incur vibration on the unloaded side of the belt - in the case of our spyders the bottom - because the drive pulls the belt. Once it goes around the drive sprocket its loose and flaps around.

If I could find one that mounts and applies pressure to the unloaded side. Mine is on my '17 RTL and while it has made an improvement, the belt still gets its "knickers in a twist" when you hid a bump. As for road debris hitting it, I pay sufficient attention to not need worry about something flicking up and hitting it.

 

[Mikey]

Since Can Am is installing their belt dampeners as standard equipment due to “popular demand”……It got me thinking just how much influence this forum and LaMonster sales contributed to their decision. It’s nice to have this forum to share our experiences and questions.

If they would only read the posts on tires!!:gaah:

 

[ButterSmooth]

If they would only read the posts on tires!!:gaah:

Just in case they are doing some reading, the ideal belt vibration solution is a shaft.

 

[Rattlebars]

I got myself a very good belt tension and alignment without turning the engine on. I kept rotating and checking.

I would say that the stress on the belt is not what would be the result of being "driven" by the front pulley but "driven" from the rear wheel. But hey! If it works...

 

[njfishfan]

I picked up a 2021 F3 Limited last week and it doesn't have a belt dampener on it......Should it ?

 

[RICZ]

I picked up a 2021 F3 Limited last week and it doesn't have a belt dampener on it......Should it ?

No. If you get belt vibes, try adjusting to 140 on the Krickit, wheel off the floor.

 

[Freddy]

We are on the same page. I worked as a mechanical fitter for 17 years at a 2000 Megwatt Coal Fired Power Station. Some plant that was belt driven, (Ash Crushers, fans etc) would incur vibration on the unloaded side of the belt - in the case of our spyders the bottom - because the drive pulls the belt. Once it goes around the drive sprocket its loose and flaps around.

If I could find one that mounts and applies pressure to the unloaded side. Mine is on my '17 RTL and while it has made an improvement, the belt still gets its "knickers in a twist" when you hid a bump. As for road debris hitting it, I pay sufficient attention to not need worry about something flicking up and hitting it.

https://www.spyderlovers.com/forums/showthread.php?112630-Belt-Tensioner&highlight=rosta

 

[davev1pa]

I appreciate the rear wheel adjustment for both tension and alignment and the use of the Krit kat for belt tension on the Spyder. In this video however the tension is measured with the rear wheel in the air and I find that the tension is increased once the rear wheel is on the ground...which measurement should be read as correct ...airborne or grounded ? In addition, when i loosen the rear axle I often will pull the wheel back manually to take the slack out first....