| Author | Message | ||
     Strada |
There has been much debate about the stock pulley and the sring-loaded device. I think the main issues are that the standard belt is a bit tight for the gearbox and wheel bearings but the tension is required to prevent belt breakage caused by any sudden take up of slack. I think the spring loaded part helps with the bearings but not entirely sure it fixes the whip-lash (like when changing gear whilst accelerating aggressively). The spring-tensioner seems to have little travel and no damping which can aggravate the situation (?). Some of the early Buells had tension adjustment so can only assume that there must be an optimum tension for the newer systems. I think the fixed pulley system is basically sound except for the quality of the bearings. I've just finished testing what I think is a good compromise........... I drilled out the bottom pulley mount hole until it gave about + and - 1/2" flex in the centre of the top section (in the middle). This meant drilling a 12.5mm hole in the ally carrier - very soft material so very easy to do. I found that each 1mm increase in radius gave a 3x reduction in pulley height. The results have been encouraging as the bike feels smoother and has lost a bad 'stumble' when the engine dropped past the 2k rpm mark. The belt did not slip despite me trying aggressive changes with full acceleration. I'm looking at an insert that has a cam arrangement to allow easy adjustment but for now I'm going to use different size inserts - only really need 2/3 of these to allow for a new belt and adjust as it stretches slightly. Just thought I would share as I'm not opposed to the Spring-Loaded item but I can't get my head around it 100%. Merry Christmas............... | ||
| Jcbikes |
pictures please! | ||
| Strada |
Sorry but the pulley is back on the bike - looks completely standard. It's the lower of the 2 mounting holes that I changed. | ||
| Brakes2late |
How about a rough drawing? | ||
| Johnboy777 |
 | ||
| Strada |
Sorry but all I've done is drilled out a hole from 10mm to 12.5mm - that's it. I was sharing my experience with this setup. | ||
| Longdog_cymru |
I'm pretty much in agreement with you Strada....... sort of.......! But...... I just can't see how Erik could have gotten the tensioner/jockey wheel wrong enough to compromise the reliabilty of the gearbox output shaft bearings. I know the ideal scenario would be to have the swing-arm pivoting on the same axis as the output shaft, but can the standard XB system be so wrong? I know there are some knowledgeable people on the UK Buell site who swear by the spring tensioner, but.......!!!! I have been tempted to try the spring tensioner myself, but so far, I have trusted Erik's judgement and design. I'd like to hear any comments from the US of A Buell riders, as I think you tend to do higher mileages than us in UK and Europe. | ||
| Johnboy777 |
""I have been tempted to try the spring tensioner myself, but so far, I have trusted Erik's judgement and design"" Any design that is put into production, carries with it a series of inherent compromises throughout its make up (e.g., cost considerations of manufacturing the various components, ease of assembly, by line workers, and so on)... add to that, production irregularities of the various components supplied by cost-conscious vendors (which always seem to occur), and you can end up w/ a less than satisfactory piece on your bike. It's just the way it work in manufacturing. As with anything that is manufactured to a specific price point (as are all Buells), there is 'always' room for improvement. John . | ||
| Muppet |
Longdog, I did 21,000 miles on my bike in the first 14 months of ownership. 95% of that was touring in Europe, mostly solo with full luggage on. I'm now on my 3rd belt, the first managed 8k, the 2nd got to 10k. Both times they were clean breaks, no cuts or stones and the bike wasn't being ridden aggressively at the time. The 2nd belt was the supposedly improved one. I keep thinking about the spring tensioner too, but I've heard some negative reports about it and some criticism on this board, so until now I've delayed. I won't be doing so many miles next year, maybe 8k at most so I'm hoping this 3rd belt will last the distance - I'll be carrying a spare just in case though. Be interested to hear others opinions about the spring tensioner, also very interested to see how Iain (Strada)gets on with his mod. | ||
| Prowler |
My theory on this is: The original Buell belt drive set-up was designed for all the XB bikes with shorter suspension travel. The Uly has an additional 1-1/2" or so travel (all in the down direction). This causes additional stress/tension on the belt (I heard around 25% additional load) when the suspension is fully extended and additional high loading on the rear wheel bearings, belt, and output shaft bearing. Enlarging the rear lower hole on the idler pulley mount will reduce the tension when the suspension is fully entended (which is good), but....as soon as the suspension starts to compress (oh, an 1-1/2" or so, the belt will be more loose than it's supposed to be (or designed for). I had pondered this (and a cam style adjuster in one of the idler holes, which would produce the same results), but personally decided that this was not the correct answer to the issue. Having designed some cogged belt drive systems in the past, I prefer the (Free Spirits) spring loaded tensioner and have it on both the bikes (STT and Uly). These have been functioning well since I've started using them (other than a small manufacturing hick-up from Free Spirits that had to be fixed. The tensioners were sticking due to a too-tight fit on the pivot shaft). (Message edited by prowler on December 21, 2008) | ||
| Skinstains |
Chain drive rules. | ||
| Dick_stilton |
On topic.... kind of.... I have a FSBT but because of the online debates I have resisted fitting it so far but now I think I will.... or rather will get my dealer to do it as they so overtightened the wheel nuts last time the bike was in the shop I want them to sheer the axle not me. However, I just looked in the box and cant find the instruction sheet in German, I know it came with one.. does anyone have it that can perhaps scan it for me? Cheers. Dick | ||
| Rotorhead |
+1!! Skinstains | ||
| Longdog_cymru |
Prowler, I agree with what you are saying. This would concur with what has been written on the UK Buell site. Muppet, From what I have read, some of the US Uly owners have done considerably bigger mileages without belt breakages. What is different? Skinstains, I bought a Buell to get away from a chain. The regular maintenance, vibration and general dirt and mess are minus points compared with the smoothness and lack of snatch with a belt. Dick Stilton, if you have a Free Spirits tensioner, I recommend you look at the UK Buell site for Maz's instructions on fitting the unit to an Uly. "Maz will correct me, but I think the official way is to disregard the shims, use the smaller washer to space the wheel as far to the left as possible, then use the two bigger washers to space the tensioner out from the engine. This reduces the risk of the tensioner rubbing on the exhaust clamp." | ||
| Skinstains |
Understood, I have an automatic oiler and don't mind a dirty bike. Different strokes... | ||
| Dick_stilton |
Longdog.. "Maz will correct me, but I think the official way is to disregard the shims, use the smaller washer to space the wheel as far to the left as possible, then use the two bigger washers to space the tensioner out from the engine. This reduces the risk of the tensioner rubbing on the exhaust clamp." Having dug the thing out of the box and taken a long hard shuffti thats what I understand... you want it away from your box.... BTW thanks for the tip, I found Maz's instructions. (Also, Matt from trojan emailed me so full marks to his after sales service) Have a good christmas and not too much 'Brains SA'! | ||
| Hughlysses |
I just can't see how Erik could have gotten the tensioner/jockey wheel wrong enough to compromise the reliabilty of the gearbox output shaft bearings. One thing worth mentioning here: AFAIK nobody (here or at advrider at least) has ever reported failed output shaft bearings on an XB. OTOH failed rear wheel bearings on Uly's seem to be pretty common. Failed output shaft bearings were a relatively common thing to occur on a tube-frame Buell if the belt was over-tensioned (tubers had an adjustable rear axle), while axle bearing failures seem to be rare. Of course, tubers had three rear wheel bearings, featuring an extra bearing on the sprocket side. | ||
| Longdog_cymru |
Hughlysses, Thanks for this. On the UK site, there are a couple of people who say the contrary, that's why I asked the question here. As I mentioned, American riders appear to have covered higher mileages AND to have taken their bikes off-road, whether fire road or gravel track, so with this in mind, I value the experiences and opinions offered on this site. | ||
| Muppet |
Short answer to your last statement Longdog - could it be that for the most part, American roads are 'kinder' to belts? Less dense traffic conditions mean less stress and strain on the whole drivetrain setup? I know there will be exceptions to this, but I wonder if this could be an overall factor? | ||
| Froggy |
Muppet I doubt it. Mine snapped after 30k, on road, off road, 1 wheel, no wheel. I bought my bike missing a belt guard. Oh, and that was the orginial belt, not the new revised belt like I got on mine now. | ||
| Growl |
Froggy, you mention a new revised belt... Is this different than what came stock on my 2006 Uly? | ||
| Longdog_cymru |
Hi Growl, Yes, to the best of my knowledge, there was a new improved belt announced a year or so ago, (2007 maybe?), and there was another newer improved belt announced a few months ago. I can't help you with part numbers, but I'm sure someone on here will very soon! | ||
| Froggy |
G0500.AKD is the old belt, G0500.1AKE is the new. |
