| Author | Message | ||
     Claretnick |
Hi, Nick here from London. Any of you chaps have one fitted to your Ulysses? Takes strain of gearbox output shaft, Rear wheel bearings and gbox bearings. not to mention the belt. Also anyone have a grease nipple fitted to the output shaft. All regarded as critical in UK oo www.ukbeg.com. Comments? | ||
| Desmo900 |
I have one fitted. I actually ride off road and im hoping the bit of give in the spring will save the belt if I get a rock caught in the sprocket. Besides, it looks cool, and that's what is really important right? | ||
| Idaho_buelly |
Where can I see one ?? | ||
| Gamdh |
Looks like this...  I like it... like the theory, but can't really say one way or the other if it really makes a difference. I have had a belt break with this on but it was not the latest belt rev. (Message edited by gamdh on August 26, 2010) | ||
| Eulysses |
Why would it take a strain off anything? Belt does not really flop much. Hmmm? | ||
| Idaho_buelly |
Gamdh Great pic!! Thank you..  | ||
| Reepicheep |
Eulysses, this has been hashed to death in the past. The "pro spring tensioner" advocates will say you can feel the suspension load up at certain points because the belt is binding, and that loose belts save belts, so you need that spring tensioner. The "no spring tensioner" advocates (which include the people that designed the bike, and the people that designed the belt), say that you want about 300 pounds of pressure on the belt at all times, and that the geometry of the stock swingarm and non spring tensioner do exactly that all the time. Other interesting side notes are around possible tolerance error stackup (implying that most bikes don't need this, but some might), and there have been a couple people reporting that aftermarket tensioner failing (meaning you broke something fixing something that wasn't broken). That's the nutshell version. More info in the archives... (Message edited by reepicheep on August 27, 2010) | ||
| Desmo900 |
The "no spring tensioner" advocates (which include the people that designed the bike, and the people that designed the belt), say that you want about 300 pounds of pressure on the belt at all times, and that the geometry of the stock swingarm and non spring tensioner do exactly that all the time. I think this is true for the normal XB's but I don't think the Ulysses could have an even 300lb all the time. The angle of the swingarm at full extension is very steep and at full compression the tire almost touches the seat pan, thats a big range of motion. Ill draw out the suspension and see how much the axle to counter shaft distance grows as the suspension cycles. eh... prolly faster to just pull the spring and use a tape measurer. | ||
| Electraglider_1997 |
Sure would be nice to have during wheel removal/installation and when I did that one belt change. I wish the original stock idler would have at least been outfitted with a bolt where that coil spring is. When you'd need to remove the rear wheel for any reason then you'd just back the bolt out to loosen the belt. To tighten the belt to Buell spec would just mean tightening the bolt back up. That would have been a nice feature and sure make belt install a breeze instead of a headache. | ||
| Mikef5000 |
I've removed XB rear wheels quite a few times without ever having to remove or loosen the OEM tensioner. Dunno what we're doing different. I think this is true for the normal XB's but I don't think the Ulysses could have an even 300lb all the time. The angle of the swingarm at full extension is very steep and at full compression the tire almost touches the seat pan, thats a big range of motion. The swingarm never changes length... so why would the belt need to? The idler pully is theoretically supposed to be in line with the swingarm pivot, to allow the belt constant tension throughout the full range of motion. | ||
| Desmo900 |
Of course the actual swingarm never changes length. But the distance from the front sprocket shaft to the rear axle will change because the swingarm pivot is so far away from the output shaft, much farther than the 1125 and most Asian bikes. As the axle, swingarm and sprocket line up, the belt distance is the greatest, as the suspension continues to compress the distance lessens. So if there is 300lb on the belt with the shock fully extended then there will be Alot more pressure on the belt when the axle, pivot and sprocket are in line. | ||
| Mikef5000 |
You are correct. Except that Buells have a specific part in place to counter the fact that the distance changes with suspension travel. (Idler Pully) | ||
| Larryjohn |
There was an article floating about that explains this in depth (maybe from an issue of Fuell). From what I recall there is a minor change in the belt path distance on XBs which is slightly increased on the Ulysses because of the increased suspension travel. I don't recall the exact numbers and haven't been able to find the article recently - I haven't really looked that hard though. | ||
| Jphish |
Hey Nick - welcome cuzzin' - A 'grease nipple fitted to the output shaft' ? Sounds like something from an Austin Powers movie. But no...not familiar with that modification. Pics / explanation please. Always looking for new ideas to overcome inherent problem areas. TTFN, j | ||
| Eulysses |
Well...with 2-up and a new (tight) belt you can feel the engine vibes during the road dips as the belt tightens pulling the engine tight in its mounts. So...the spring-loaded tensioner would seem attractive to lessen strain on engine mounts and rear bearings. I run into this on sleds when the track compresses and elongates. A four point undercarriage theoretically collapses evenly. Unless our swingarm forward pivot is the same axis as the drive pulley...there will be tension in extension and flexion of the swingarm. What you all were saying there. Euly | ||
| Desmo900 |
eggzactly | ||
| Reepicheep |
I think I know why they want that grease nipple in there... I had that 5th gear drive assembly fail on an M2. When I pulled it apart (I have some quite beautiful pictures in the archives of the carnage) the needle bearings were rusted and crushed. I think there were three problems all interacting to cause it to fail... 1) I ran the belt too tight. 2) The manual told me to run the belt too tight. 3) That assembly does not get good lubrication flow, at least on the tuber. The grease nipple would allow you to force grease into those needle bearings... not a bad idea, and that would be a really easy spot to get at and do as a part of normal maintenance. That being said, it doesn't seem to be a big problem on XB's, now that the belt tensioner system is there (and now that people started ignoring bad advice in the 2000 M2 service manual) the problem seems greatly reduced. | ||
| Electraglider_1997 |
I read about some trail bike that engineered the swingarm pivot at the engine's output shaft. Unfortunately the Buell wasn't this bike. Buell engineers weren't infallible and this belt pulley geometry could have been so much better. I think the spring thingy would help. | ||
| Desmo900 |
The current model BMW G450x offroad bike has the countershaft and swingarm pivot together. It works very well at keeping chain torque from jacking the suspension. And the chain tension stays constant. | ||
| Claretnick |
Sorry, Jphish, I don't have any pics. My Uly has done 12600 miles and belt went at 11800. Emigrating to Portugal so want the bike right as taking it. Aim to get it to at least 100000 miles. and why not? | ||
| Eulysses |
The Trojan-Horse Co. that has this spring tensioner http://www.trojan-horse.co.uk/prods/169.html also has an XB chain kit. Are they the only ones? The way I have been looking at my bike and its future is that there is no grin for the buck like these bikes and as we band together in our post apocalyptic adventure I am not hesitating to do whatever to keep it running. Not replaceable without big bucks...and then you don't have a Uly either...settling for something much different. | ||
| Itileman |
Contact Skinstains for all the details on the chain conversion. His is a work of art and can be done for well under $500.00 | ||
| Electraglider_1997 |
Chains are stronger but the belt is so much cleaner. 1 belt change for me and it was at 25,000 miles. Fortunately it happened close to home and not in the middle of the Gobi Desert. Chains wear out their sprockets and are noisy and crud magnets. Belts don't seem to have much affect on their sprockets so long as the belt is tight. Me likey belt. (Message edited by electraglider_1997 on August 30, 2010) | ||
| Uly_dude |
I just bought the spirit level tensioner, and when I get my new belt and 2010 wheel from Al, I'm going to change out the whole mess at one time. I'm like you Claretnick, I want to keep the bike around for the long haul. I know there's no hard facts about the belt tensioner, but for a hundred bucks with a new belt and new bearings(the two weak links on this bike) why not? I figure if I carry a spare belt, I'm covered now. It's the price to pay to ride a pretty neat bike I think. Actually you don't even need to get the 2010 wheel to have solid normal bearings. | ||
| Ftd |
Hey Uly dude, How long did it take for you to get the tensioner after you ordered it? I have a 2010 wheel and new belt and might give the tensioner a try too if the wait is reasonable. TIA Frank | ||
| Eulysses |
Uly_dude...I am with you. That set up might save on engine mounts too. A guy could always rebuild that tensioner if fails...or fab one. Any design that drags on the motor that hard in a two up dip has have some relief I am thinking. My thinking is sometimes suspect however. I do like the belt too...chain would be a last resort to keep it on the road. Euly | ||
| Uly_dude |
Hi Frank, the tensioner arrived pretty quick considering it came from across the pond - like a week to 10 days. And it's exactly as advertised. I got the red to go with the rest of my red parts. I hear what you're saying Euly. You can either deal with chains/sprockets/lubricating/noise or stay with the belt/maybe breaking/keeping a spare with. I'm going with the later. | ||
| Towpro |
here is the link again to the original Patent showing why they say you don't need a spring loaded tension device. It explains how it works pretty well. http://www.freepatentsonline.com/6866112.pdf | ||
| Eulysses |
Towpro...thanks for that patent info. I really get it now. Ideally (and I mean ideally) the math allows the belt to "lengthen" as the suspension collapses. Good idea. Somehow the math is not quite right on the Uly and I suspect it was not re-engineered for the longer Uly suspension. If the XB belt guide part numbers are the same as the Uly belt guide...and belt pulleys are the same...hmmmm. | ||
| Eulysses |
Well, Al from American Sport Bike responded when I asked him to carry the spring thing and I reprint with permission: "I don’t buy into that spring loaded pulley..I’m quite aware of the spring loaded pulleys and don’t believe they solve a thing. The swingarm is hard bolted to the back of the engine, the C/L of pulley to pulley doesn’t change with isolator flex. The idler location and diameter is designed to maintain a fixed path length, see the attached. Any time you see a spring, look for the damper. If there isn’t one, question resonance and it’s effects. Springs store energy, they only marginally dissipate it via hysteresis. The wheel bearings are marginally sized for the application, thus the three bearing wheel. Tube frame Buells had three bearing wheels for a reason, not sure why they didn’t see fit to include them in the XBs from the gitgo." Al included a copy of a Fuell article on the development of the fixed pulley system which was born of Erik's desire to keep the wheel below center to keep the bike from squatting when accelerating (thanks Erik). I asked Al if the XB pulleys involved were the same parts because I was thinking the math for the belt tension was just passed onto the taller Uly which is why my bike "groans" with 2-up dips (and a new belt I have to add). He responded: "We’ve covered it before on badweb and I’ve said the same thing. Folks that believe in them swear by them, Trojan (who sells them) claims that bikes with them don’t break belts, and other bikes without them do, but I’ve had such little problem with belt breakage myself, I remain unconvinced. One theory that folks that support them is that the constant belt tension provided by the idler geometry is an approximation based on the “normal” travel. PERHAPS the additional extension that occurs when the rear wheel leaves the ground moves the constant length approximation out of spec. I think Trojan has stated this before. I don’t do many stoppies, perhaps those that do would benefit from them. I do the occasional stoppie, a fair amount of wheelies, and ride my bikes reasonably hard, and while I have lost a couple teeth on a belt, I’ve yet to break one. I haven’t seen the Buell calculations, so I don’t know how much change there is during hyperextension during rear wheel lift. The idler PULLEY is the same on the Uly, but the Idler LOCATION (i.e., support bracket) is NOT. The belts DO stretch slightly during initial installation. I’ve had many a customer call and say that they must have the wrong belt, because when first installed they are so tight that they are off by half a tooth by the time they are ¾’s wrapped around the rear of the pulley. But after running it for even a couple miles, that is no longer the case." Al At this point I have ordered the 2010 wheel and Al's offer to install bearings. I will keep a couple of engine mounts on hand. Verdict still out on spring thing. Maybe when my belt loosens up a bit it will not drag the engine toward the frame so much. Euly |
