| Author | Message | ||
     Mbest |
Gentlemen, Here's the deal.... The belt only gets tighter and looser by about the amount thats published by Buell. A Confirmation of that is evidenced by my Uly's spring loaded tensioner, In that with the shock off the bike and the wheel, belt and tensioner in place, the idler moves up and down less than an 1/8 of an inch during full up and down travel of the rear wheel. (same on a friends Lightning). Clearly 100 horsepower of engine power and engine braking on down shifting can stretch the belt and the tensioner can take up that slack. There is going to always be the weight of the bike and the engine power creating wear on the belt and rear bearings. The 2006 belts naturally loosened up a bit after a few miles were put on them. After that the belt and bearings only had to deal with the HP and weight of the bike, not the added strain of a guitar string tight belt like the new ones that are stiffened up for the extra power of the 1125 bikes. So thats the advantage of the spring tensioner on belt and bearing life. The "growling" and vibrations are not the belt getting stretched or loose on suspension travel. When you "load" the rear suspension (two-up, bumps, whatever) you are compressing the spring. My bike had the 450# progressive stock spring on it (620# strait rate now). With 20mm of preload, add a few inches of shock travel and your getting close to a 1000 pounds of pressure pushing on the swing arm and the top shock mount. That pressure actually PULLS the swing arm AWAY from it's pivot in the motor. There's no real play at the swing arm pivot so the "pull" is transferred to the motor as designed and the load is transferred to the frame via the rubber motor mounts. The back mount is rather robust and doesn't flex all that much, but the motor will rotate around it and be limited by the front mount. If the front mount allows too much travel (rotation) from the suspension forces it can bottom out on it's retaining flange and transmit engine vibration to the frame. Thats the vibration you feel on big suspension travel occurrences. Put some modeling clay in the air gap of your front isolator and road trip the bike over your favorite big suspension travel bumps and then look to see how much clay gets squished out. Most of the time swapping in a new front isolator will cure the vibration with out addressing the sturdier rear mount, but the rear mount can take a "set" from thousands of miles of use placing more forces on the front isolator. that's 2 more cents, I'm up to $.04 on this one so far, don't want to get into the 401K  safe riding, mike | ||
| Nobuell |
Mbest, Your explanation makes perfect sense. The load must travel to the most fixed point. However, I am having a difficult time determining why the vibration was eliminated after adjusting the belt tension on my bike. Same bike, same load and same bumps. Specifically the bump that really exposed the vibration is on the expressway a couple miles from my house. We pass over the bump virtually every time we go for a ride. The shock setup is the same when I adjust for two up riding. Actually the spring preload is set to maximum when riding two up and damping set-points are according to the manual. This is an interesting issue. | ||
| Treadmarks |
Its not rocket science gentlemen. In the case of the Uly, Buell got it wrong. What seemed to work on the little XBs was not compatible with the longer travel on the X. Before the FS belt tensioner My 06 Uly belt was just unnecessarily tight. The belt harmonics under full load on my bike and the 08 Uly I rented in Alaska were awful. Mine hardly had any deflection when a static load was placed on the seat. I did have a wheel bearing failure, although water intrusion from inside the wheel was partiality suspect for me, I am sure the unnecessarily high belt tension was a contributing factor. Immediately after installing and setting up the tensioner properly, I had longer usable rear suspension travel, a smoother ride under load with zero belt harmonics, wheelies were easier, hard braking was more controllable and I now had considerably less rolling friction as noticed in how much farther the bike would coast at low speeds. Everything my Uly did well, with regard to the rear suspension, it did better with the FS Tensioner. Five years, 6 rear tires, 15k more miles as a daily driver/hooligan fix provider/back road blaster/two up weekend tripper, and hundreds if not a thousand of tire chirping wheelies later I find my uly still on the factory drive belt without guards. I have seen a socket pass through my spinning belt without any harm to belt or sprocket. I like the fact that if a piece of gravel managed to land on my belt that it would probably just spit it out the other side without incident, instead of punching a hole in my belt and chipping a tooth on my rear sprocket as I and many others have witnessed on this website over the years. One can not overlook the importance of a correct installation with the FS Tensioner. It may not just bolt on and be perfect right out of the box. I did need to shim for alignment and tractability and tension preload per Matt's instructions. How many bearing, belt or other related failures do you think Buell could have avoided on the Uly by adding this one simple device? I have only had a single issue with my tensioner and it had no impact on the form, fit or function of the device. After 5 years of rather tough use/abuse, the pretty yellow powder coating on the spring flaked away. Bummer, now it is black. Big deal. If I wasn't so darn lazy I would ask mat for another, but why? Does the Uly need an improved drive belt tensioning device, YES. Does the FS Tensioner fill a gap in a design flaw associated with the X line, YES. Does the FS Tensioner provide a return on you investment by decreasing friction, increasing longevity of drive line components and/or free up power that is already there, YES. Is it possible that some folks on this forum may never admit that someone else improved on uncle Erik's design, HELL YES! YMMV yada yada yada | ||
| Brucespoint |
 b. | ||
| Andymnelson |
Wait wait wait....are you trying to tell us that the Messiah and his angels are fallible?? | ||
| Ratbuell |
Does the FS Tensioner fill a gap in a design flaw associated with the X line, YES. Does the FS Tensioner provide a return on you investment by decreasing friction, increasing longevity of drive line components and/or free up power that is already there, YES. OK. PROVE IT. theory is nice and all...but there have still been belt failures on bikes with the fst. there are people still getting the 'buzz' on bikes with the fst. PROOF. till then, i won't lighten my wallet for one. | ||
| Prowler |
Treadmarks, a giant  for me. Until you actually experience the difference in the ride, you won't get it. | ||
| Electraglider_1997 |
Terry, You'll be flayed alive  | ||
| Eulysses |
So Mbest...you said it. The front of the motor is pulled to the frame by the belt in the dips. So if a tensioner could cut the belt some slack in the dip...less pull on the motor. Wife does not feel fat. All good. And if Erik had been left in the saddle this forum would have forced a design change here I believe. NOTHING like a team of step-elves for R and D. | ||
| Trojan |
Does the FS Tensioner fill a gap in a design flaw associated with the X line, YES. Does the FS Tensioner provide a return on you investment by decreasing friction, increasing longevity of drive line components and/or free up power that is already there, YES. OK. PROVE IT. theory is nice and all...but there have still been belt failures on bikes with the fst. there are people still getting the 'buzz' on bikes with the fst. PROOF. till then, i won't lighten my wallet for one. There is plenty of anecdotal proof available from owners who have these fitted over a 10 year period. Try looking through UKBEG.com to see comments and recommendations (I have nothing to do with that site so certainly don't influence it!). What people seem to forget is that belts will wear over time and mileage regardless of the type of tensioner you have fitted, so of course there will be people who are unlucky enough to break a belt through foreign object damage or wear and tear with the FS item on. The point is that these will be a lot less than without it. One of the biggest causes for belt failure is shock loading, caused when suspension movement is sudden and severe such as going over pot holes or speed humps. This si the single biggest cause of belt failure in our experience, not stones or other FOD. This is where the sprung tensioner really does come into its own by absorbing some of the shock rather than letting the belt take it all. The FS tensioner is never designed to reduce 'buzz' nor to 'free up' engine performance as you suggest, but to prolong belt and bearing life and to reduce the impact of the belt tension on suspension movement. It achieves all of these quite happily. The bottom line is if you don't believe it will work don't buy one If you do decide to go with one I am sure you will be impressed with it just as Treadmarks has been with his. Simple  | ||
| Ftd |
I just ordered one...Treadmark's testimonial convinced me. Actually, I hadn't added a farkle to the ULY in a while and I tell you when I switched to the 2010 rear wheel along with a new belt a year or so ago I couldn't believe the tightness of the belt. These tensioner discussions bring back memories of the RSS. I bought a RCRINS version back in 2006...whew what a bad decision that was made out to be at the time! | ||
| Treadmarks |
OK. PROVE IT. theory is nice and all... PROOF. till then, i won't lighten my wallet for one. Relax Rat.  I'm not here to take any money. Just tellin the truth, in my typical thread killin fashion. Besides, these theories were indeed proven, a very long time ago, by men far greater than you or I. | ||
| Treadmarks |
Terry, You'll be flayed alive. Yeah, I know, Craig. What the heck, truthin always has a way of doin just that. Ain't it cool!  | ||
| Nobuell |
ftd Same here. I replaced my belt and wheel at the same time. As discussed above, I could not believe how tight the belt was. The belt side bearing on my old wheel flew apart. The wheel was dry on the inside. The belt tightness when replacing the 2010 wheel is what made me investigate the required belt tension. I am thinking about the FS tensioner as well. | ||
| Blake |
Sorry Terry, I don't see much in the way of truth in your theorizing. But I'm an engineering analyst with a background and advanced education in statistical analysis so my threshold for what is perceived as truth is pretty rigorous. Your experience is interesting, but entirely anecdotal. I tend to agree that if the belt is too tight due to excess tolerance, it likely would be a problematic. Matt, Have you taken into account the newest belt technology. The newest belts are much improved and much more resistant to abuse and damage. If you can say how many of the spring tensioners have been installed and how many miles on average they have accumulated, versus how many belt or bearing failures and the miles on the belts or bearings, we might be able to have a meaningful comparison. We'd also need the same data for late model belts. Lacking that, I just don't see that it's possible to make any certain claims, especially concerning belt longevity. The rear wheel bearing issue seems most pertinent and justifiable if some belts are seeing higher tension than intended. Vague statements like Terry makes about the belt being "guitar string tight" are near worthless. Guitar strings don't carry much tension relatively speaking. Reporting deflection versus lateral load at mid-span of belt would be valuable. The post by NoBuell was very informative. It contains actual and pertinent factual data. I'm going to check my Uly belt and consider doing what Tim (NoBuell) did to reduce the tension if needed. I don't see how suspension action, no matter how severe would adversely affect the belt. The belt path remains constant, to within +/- 0.004". | ||
| Reepicheep |
I have a new belt in the garage waiting to go on (old belt and bearings are fine at 20k miles, but I got a new belt so the old one can be a hot spare). I plan on making a bigger mounting hole in the tensioner mount before it goes on. I'm not sure it will help, but I'm even *more* sure it won't hurt, so I'll roll the dice. | ||
| Electraglider_1997 |
The only thing I would add is that Harley belts are adjusted with a 10lb fishscale to a certain deflection. Also in Buells case that given manufacturing tolerance +- of the belts some are going to be even tighter than others. And don't forget all the tolerance+/- of the ULY in regards to all swingarm, pulley, and idler parts these differences can all add up and create terrible tension on the bearings until that belt stretches. I don't like having to mess with axle adjusters but it would have been nice if Buell would have given us a circular slot on a radius (with adjustment screw to tighten the belt to some spec) for one of the studs to fit into on the idler pulley. Would have made belt changes a breeze instead a headache. Also the bearings would have breathed a sigh of relief. | ||
| Blake |
The tolerances should have been accounted for in the pulley positioning so that at worst case, the belt tension would not be problematic. The newest belts seem to be more compliant, so maybe that is also a good solution. | ||
| Eulysses |
In any case, Brother Buellers, the "ronk" from the dips on the Uly is a design flaw. Something is causing inappropriate stress. Add bearing failures and belt failures...this is a topic to pursue. I surely appreciate the quality of thinking and temperaments of Uly riders. Makes for good discussion and problem solving. | ||
| Treadmarks |
Ya know Blake, Why is it everytime you attempt to challenge a fellow members opinion or belief, you feel so compelled to toss out a list of qualifications you may or may not possess? Are you concerned that your opinion alone (because that's all it really is) is incapable of making it's point? Your alleged qualifications have zero impact on what I said or believe, only on what you say or believe. Besides, I don't recall asking you anything, why are you here hackin on me? Can't a fellow member simply answer the OP's question without the kool aid kid launching a campaign? I suppose this sort of etiquette is promoted in analyst school. Have you taken into account the newest belt technology. The newest belts are much improved and much more resistant to abuse and damage. This post isn't about the newest belt technology, Blake. The OP is requesting feedback and thoughts on the "Spring loaded belt tensioner". If you feel so compelled talk about new belts here is a thread on that. I am sure that they would appreciate your highly qualified opinion, because they are asking for it there. Vague statements like Terry makes about the belt being "guitar string tight" are near worthless. Wow. I really didn't see that one coming. Oh, wait...I get it. Your making that up, huh. Yeah, you gotta be, cause I didn't say that in this post. Must be one of those fancy analyst school tricks. You got me there, Blake. I will try to be more ready next time.  Guitar strings don't carry much tension relatively speaking. Reporting deflection versus lateral load at mid-span of belt would be valuable. You're serious, aren't you. For decades the industrial and robotic sectors (and Ducati motorcycles) have been using the acoustic report (Guitar Strum) of a tight cog belt to quantify it's tension and allow it to be perfectly replicated after repair or replacement. This practice is called strumming the belt, and I'm surprised you wern't taught that. This repeatability allows more complete usage of the belts predictable lifespan. I was doing this professionally back in the 70s and currently on My Ducati using this. This is what it means to be guitar string tight, but this thread isn't about that, remember? I'm going to check my Uly belt and consider doing what Tim (NoBuell) did to reduce the tension if needed. You go Blake. You take that rat tail file and commence to hacking. Now we know haw an analyst thinks! I don't see how suspension action, no matter how severe would adversely affect the belt. The belt path remains constant, to within +/- 0.004". You wouldn't, would you. I give up...no wait....I would like to leave all with this single tiny parting truth. (pardon the quality, it is really old.) | ||
| Eulysses |
BTW...given that the swingarm is pivoting in the frame and not the engine...it has to be the belt pulling the motor into the front mount. | ||
| Blake |
Sorry to have so offended you. That was not my intent. Try to stick to the issues. You claimed "truth"; I don't see it. Sorry for the misquote. Yes frequency of vibration correlates with tension carried by flexible chords. My point was that we don't know the relation to discern belt tension from frequency for our drive belts; "guitar string tight" is purely subjective, is vague, and may or may not be acceptable. Better then would be actual data such as deflection versus lateral load at mid span. That's all. It's the internet; mere speculation being passed off as "truth" is to be expected. We do our best to distinguish between the two here. Most folks appreciate that. A few react with hateful indignation, which is unfortunate. We can do better. | ||
| Billyo |
I have an RSS and dynabeads for my Firebolt so I suppose I should try one of these snake oil tensioners for the Uly. When the PR2 wears out perhaps I'll switch to the darkside if it will fit (it'll be extremely close). That way after I ride a few thousand miles and don't die a flaming death and my balls don't fall off I can report it here and be told that I'm wrong and it really didn't work. | ||
| Danair |
Belt broke today at 17k. Prior bearing failure and wheel damage prompted me to install 3 bearing wheel. I could easily spin the idler by hand on or off the bike. Can't do it on my 07. Anywho, replaced the belt today and it is tight. Not wanting to use subjective/empirical values such as guitar strings, piano wires,etc and using the latest technology and methods, I can report with total confidence that it IS tighter than a fat lady's sock | ||
| Billyo |
I don't know how you expect everyone to take that post seriously. You didn't say what size the sock is or if it has the same dimensions as other socks of that size. Are the dimensions consistent from one batch to the next? | ||
| Treadmarks |
If the fat lady's sock is polyester, use two flat washers and a rat tail file to reduce tension. If the fat lady's sock is nylon (with stripes) use four flat washers and a smooth mill bastard to correct tension.  | ||
| Electraglider_1997 |
Liposuction and wiring the jaws shut would be more permanent. | ||
| Danair |
Really, guys? Your Tom Foolery is impacting the validity of my research and analysis. This is serious $hit. | ||
| Ratbuell |
Something is causing inappropriate stress. And I still believe that "something" is simply overloading. The Ulysses platform makes it WAY too easy to load past GVWR, and it's a testament to the design that the handling and overall behavior is unaffected by being a couple HUNDRED pounds too heavy. Those pesky engineers simply made it capable of hauling too much stuff...whether it's stuff in the bags or stuff on the passenger seat or a pile of farkles. And, items like bearings or belts....are spec'd to handle the GVWR, not "GVWR+". (Message edited by ratbuell on August 21, 2011) | ||
| Skinstains |
"...do people forget, the belt gets LOOSER as you compress the suspension" Wrong... |
