| Author | Message | ||
     Mojo |
Just wondering about the Free Spirits Belt Tensioner. Has the tensioner - over time - shown to be a good investment? Do you think the spring tensioner actually reduces the critical pressure points that cause(?) bearing failures? Thanks for your thoughts. Darryl | ||
| Badrap |
I know they had some sticking problems with a batch of the earlier version. I don't know if the current one works like it should. Be careful if you get one that it's not the old one. | ||
| Froggy |
From what I have seen, there is no proof that the tensioner does anything to improve belt or bearing life. There just isn't enough of them out there to have a good sample. They do look cool though. | ||
| Prowler |
I've got a couple mounted on two different bikes. Turns out both were from the "bad batch". No worries though, as the correct replacement parts were sent ASAP for No Charge. Tensioners work great in my opinion. I spend much less time worrying about potential belt and bearing failures now. Opinions abound here regarding these units (good and bad). | ||
| Prowler |
Froggy is correct regarding documented proof if these things work or not. Unless there are a large quantity of these tensioners on bikes out in the real world with high mileage on them, it's opinion and speculation. Since there are guys with stock 12X's that have 25-50K miles on them without belt/bearing failures, it can't be proven with any consistency that there is an actual problem/solution. All I know is that from past personal experience in dealing with cogged belt drives in power transfer applications, we never ran them anywhere near as tight as the belt was on my Uly. I just wasn't comfortable running it like that. Much happier with the drive system as it sits now. | ||
| Mojo |
Are there different models of this tensioner (older vs newer) that i should be aware of, and therefore avoid or consider? Thx. | ||
| Froggy |
No, there is only one. The issue was just a bad batch. The seller (Trojan) stands behind them, and promptly got the fixed ones out to those with the bad ones. This was a few years back, I don't think its an issue anymore. | ||
| Od_cleaver |
My Free Spirits Belt Tensioner arrived at my door about 30 minutes ago. I am putting it on because under the right conditions (road bumps, load and suspension settings), I can feel the engine vibrations through the bike's frame. I think that this is because when the bike's suspension compresses, the belt tension increases and pulls the engine hard against the rubber engine mounts. This can not be good for the belt, bearings or engine mounts. I weigh about 220#. The load is my camping gear, about 50#. I set the suspension up on the soft side for touring. I have never had the suspension bottom out. | ||
| Motorbike |
My question is, does the belt really get tighter as the suspension compresses? It seems to me that it would get tighter as the swingarm travels downward past the normal amount and the belt presses harder against the fixed idler pulley. Anyone else? | ||
| Elsinore74 |
http://www.trojan-horse.co.uk/prods/169.html Manufacturer states: "The stock Buell belt tensioner is designed to keep the belt under constant tension, except it doesn’t! When the suspension is completely unloaded, such as when pulling stoppies or even braking hard, the tension is increased to an alarming degree, which can actually damage belts, wheel bearings and pulley bearings. This spring loaded item is designed to maintain a tension of 10.5kg regardless and will help lengthen belt and bearing life. Extensively tested in competition this is a must have accessory." Their words, not mine. I think suspension compression, if beyond the narrow range in the middle, could also affect tension. How much of an effect is the question. | ||
| Hootowl |
The idler pulley is placed in the precise spot that eliminates changes in beltpath length during suspension travel. A spring tensioned pulley should not be necessary. That said, I'd sure like to retrofit one on my X1. | ||
| Dr_greg |
Since the axes of swingarm and sprocket are not collinear, there is NO placement of the idler pulley the will ELIMINATE belt length variation during swingarm rotation. The idler pulley is supposed to MINIMIZE this variation. I know for a fact that belt tension is HIGHEST at maximum swingarm EXTENSION. Was always gonna do a geometrical analysis of this, but never did (yet). --Doc | ||
| Ll7 |
od cleaver, How long did it take you to get your tensioner? I ordered one on the Feb 22nd and the said it shipped on the 23rd and I should see it any day (that was on the 25th) and still haven't seen it. | ||
| Longdog_cymru |
How about someone doing a definitive check? Simply take the shock off, jack the wheels off the ground and move the swingarm through it's full range of travel. Then write here and let us all know  | ||
| Od_cleaver |
L17, I believe that I placed the order late on Thursday, 2/25. I received a confirmation note on Friday, 2/26. I received a ship notice on Monday, 3/1. Fed Ex delivered it today (Wednesday), 3/3. I call that good service. | ||
| Dio |
od cleaver- are you sure the front upper motormount is good? Some have posted engine/frame vibration or noise with failed mount. | ||
| Mojo |
Excellent feedback gang, thanks. Regarding this issue, I am now sitting firmly on the fence - with a cold beer, of course! | ||
| Hootowl |
"The idler pulley is supposed to MINIMIZE this variation." I stand corrected. | ||
| Towpro |
Here is Erik's patent paperwork, It is titled Motorcycle having stationary belt tensioner, United States Patent 6866112 The link below explains how it works. http://www.freepatentsonline.com/6866112.pdf (Message edited by towpro on March 04, 2010) | ||
| Od_cleaver |
Dio, I have looked at the front mount and I have looked at pictures of failed mounts posted on this forum. My mount was good the last time I looked. Thanks for the suggestion. | ||
| Pso |
If I remember correctly when I was asking about that neat looking little spring loaded belt tensionar folks on the other side of the pond reported that they found it beneficial, but as has been reported above no empirical testing results, that I am aware of. It sure is a pretty looking thing, in keeping with the industrial look of the Uly. | ||
| Skinstains |
The belt will absolutely be at it's tightest when all the stars are in allignment. The stars being the front sprocket, swinging arm pivot, and the rear axle. Tell'em Doc. | ||
| Nadz |
"In the described embodiment, the belt path length remains constant to within approximately .008" as the swingarm pivots through its complete range of 16 degrees." -Patent US6866112 Thanks for posting Towpro. I'd often wondered how that worked, since the sprocket and the pivot obviously weren't coaxial. .008" would be a lot of elongation in the case of a screw, but it's a pretty small percentage of belt length. The advertising reminds us of Fuel-in-Frame and ZTL, but it's finesse moves like this that really impress me with how well these are designed. | ||
| Desert_bird |
While in Afghanistan I store the Uly back in the states. I'm gone for extended periods - up to 10 months per shot. I'd been planning to raise her with some supports under the muffler, to ease the compression on tires and front and rear springs. (I intend to keep her for years and despite my best attempts, she does age even when sitting in a shed.) Perhaps I should get the Trojan thing'ama-jig to ease tension on the belt when she's jacked up and rear suspension is at full extension, or pull off the belt altogether. | ||
| Bryn1203 |
the free spirits belt tensioner is generally regarded by Buell enthusiasts in the UK as a 'must have'. As is a sense of humour  (Message edited by bryn1203 on March 06, 2010) | ||
| Dr_greg |
Is that necessarily true? Could be, but sounds like an over-generalization for an arbitrary mechanism. But I've not investigated the geometry; it's not as straightforward as I originally thought...kudos to the BMC engineers for their design. --Doc | ||
| Teeps |
So somebody needs to remove the rear damper assembly. Then stroke the swing arm through its travel arc and settle this discussion once and for all... Who's up for it? | ||
| Larryjohn |
I recall reading somewhere that the Uly, with its longer suspension travel has a bit more in the change in belt path length than other Buells, so I would guess for the Uly it is more than .008" Now I wonder what the impact of old belt vs new belt has on this? I haven't replaced my belt yet, but I have heard that as you put the miles on a belt it gets a little stretched. I would imagine a well worn belt would have much less stress on the bearings. I'd be curious to know if there is any significant difference between the two (new belt/old belt) |
