Author |
Message |
Blakeaspencer
| Posted on Wednesday, October 12, 2016 - 10:54 am: |
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I read an article on adv rider the other day about the uly belts breaking due to "stoppies", that got me thinking. I like to ramp mine off of bridges or bumps in the road. Would this full unload to full compression cause a large enough strain on the belt to break it? I know the idler pulley is supposed to be in a place where it is under constant tension but i'm not satisfied with that, because under full load I can feel a grumble of the belt due to squat of the rear end. |
Natexlh1000
| Posted on Wednesday, October 12, 2016 - 11:09 am: |
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Each time I lost a belt it was under rapid acceleration in first or second gear while going over a pothole or other surface irregularity. This includes the failures I had on my X1 which is run scary loose with no tensioner at all. Very rapid loading/unloading/loading of rear tire. It may not be the tension that pops them. |
Tootal
| Posted on Wednesday, October 12, 2016 - 12:08 pm: |
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The rumble of the belt while squatting has been discussed here before and the rumble was said to be the engine vibration not the belt. It sure feels like the belt but what was explained, if memory serves, is that when the suspension is compressed the motor mounts also compress and you are feeling the engine vibrations since the rubber mounts get into a bind. |
Dr_greg
| Posted on Wednesday, October 12, 2016 - 12:14 pm: |
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I thought it was common knowledge that the belt is under greatest tension at full swingarm extension. That is the most likely time for it to break. --Doc (recuperating from yet another broken arm) |
Reepicheep
| Posted on Wednesday, October 12, 2016 - 01:20 pm: |
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Geesh Doc, again? Hope you heal well. |
Ourdee
| Posted on Wednesday, October 12, 2016 - 11:06 pm: |
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Doc you need to stop that. |
Mark_weiss
| Posted on Tuesday, October 18, 2016 - 11:01 am: |
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Has anyone ever actually measured belt tension at different swingarm positions? My anecdotal test from a few years ago (how hard is it to turn the idler pulley) indicated no significant change in tension throughout the range of movement. I wondered if anyone ever checked with some sort of tension gauge? |
Skifastbadly
| Posted on Tuesday, October 18, 2016 - 05:16 pm: |
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I consider myself an expert on belt breakage, having busted about five of them. In each and every case it was under heavy acceleration. |
Surfsofa
| Posted on Tuesday, October 18, 2016 - 06:41 pm: |
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This is why I elected to fit a Free Spirits Tensioner on my Ulys. It certainly doesn't do any harm, and the logic of a spring taking some of the stresses the belt would take makes sense to me. |
Blakeaspencer
| Posted on Wednesday, October 19, 2016 - 08:19 am: |
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A little off topic. In theory, if a rock decided to get in between the belt and pulley, would the free spirits tensioner allow enough movement to allow the rock to pass through without busting the belt. I've had a belt break because of a rock, granted it was an 25k belt. |
Reepicheep
| Posted on Wednesday, October 19, 2016 - 09:07 am: |
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The tensioner itself has enough play, but I'm having trouble picturing how the belt teeth would line up with a rock in there. Would they "skip a tooth" and give the belt margin? Or would they try and realign, and put pressure on the rock regardless of the degrees of movement in the tensioner? I always drill out the tensioner mounting holes to have a lot of play, then push the tensioner up firmly with one hand while tightening the nuts with the other. So I am preloading the tensioner to maybe 10 pounds. I don't know if the belt would snap from tension before the bolts would let the whole assembly rotate when I have it configured this way. Maybe the belt is the mechanical fuse, maybe the tensioner is. I have no idea. I've never lost a belt, and never had the tensioner loose the tension I set between tire changes. I do the "big holes thing" so I can do a road side belt replacement or a tire change more easily. It means I just loosen the tensioner, not remove it, and it makes the belt and rear wheel a lot easier to get on and off. I know in theory it is lowering my belt life, but I have over 100k miles on Buells and never lost a belt. Probably because I keep a spare with me at all times ready to go in the side bag. I already paid off Murphy and his law. |
Dr_greg
| Posted on Wednesday, October 19, 2016 - 11:47 am: |
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Just got my cast/splint off so I can again type with two hands... A while back (when I still owned the Uly) I began an analysis to determine the variation in belt length due to swingarm motion. It ain't easy (the idler pulley complicates the geometry), even for hotshot engineer me. I decided to pursue activities with more immediate gratification. --Doc |
Buellerxt
| Posted on Wednesday, October 19, 2016 - 12:36 pm: |
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Bill, You were definitely the right guy for my Uly! You are one knowledgeable guy. Now, if I had a friend like you, who lived down the street, that Uly might still be mine. . I still lurk and am impressed with your input in many places throughout Badweatherbikers. Doc Greg, How did you hurt your arm? Still riding that GS? Hope you feel better soon. |
Reepicheep
| Posted on Wednesday, October 19, 2016 - 01:55 pm: |
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Good to hear from you Mike! I'm still loving the XT. |
Rocket_scientist
| Posted on Wednesday, October 19, 2016 - 03:46 pm: |
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Mark weiss: "My anecdotal test from a few years ago (how hard is it to turn the idler pulley) indicated no significant change in tension throughout the range of movement." You are correct, that is by design |
Hugie03flhr
| Posted on Wednesday, October 19, 2016 - 04:04 pm: |
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Wow, I just checked out that free spirit belt tensioner. It's a nice piece of engineering but $160 plus shipping is a bit step. I guess my first question is, does it hold up over time and abuse or will I be buying one with every belt change? |
Natexlh1000
| Posted on Wednesday, October 19, 2016 - 04:48 pm: |
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Those have been known to fail. There was a weak spot near the pivot where a roll pin was placed causing a weak spot. You have to tune them too. One more thing to worry about if you ask me. I think it's smarter to enlarge the mounting holes in the stocker a bit. The price is right, eh? |
Reepicheep
| Posted on Wednesday, October 19, 2016 - 04:55 pm: |
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Agreed. They have to be shimmed to fit, the bearing can fail, the springs are a regular replacement item, and there is a pivot point that fails sometimes. They look cool, so if somebody wants one, its a pretty piece of jewlry. But I'm with Nate in terms of unsolving solved problems. (But I haven't had a belt serial killer Buell either... if I did I might think differently) |
Hugie03flhr
| Posted on Wednesday, October 19, 2016 - 06:38 pm: |
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Thanks for the info guys! Oval ing out a mounting hole sounds like a good idea. |
Dr_greg
| Posted on Thursday, October 20, 2016 - 12:54 pm: |
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How did you hurt your arm? Still riding that GS? Hope you feel better soon. Don't wanna hijack this thread. Low-speed tipover on GSA in western North Carolina. Rode 2,000 miles home to New Mexico with an elbow in three pieces. I'm a little guy but apparently durable...think I'm up to 16 fractures. Surgery on 10/10; staples out today. Looking forward to next year. --Doc |
Tootal
| Posted on Thursday, October 20, 2016 - 03:01 pm: |
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A little off topic. In theory, if a rock decided to get in between the belt and pulley, would the free spirits tensioner allow enough movement to allow the rock to pass through without busting the belt. I've had a belt break because of a rock, granted it was an 25k belt. A rock will get pushed through the belt eventually. As it goes around the pulley the cogs will pull the belt tight forcing the rock through or crushing it if it's brittle enough. A hole in the middle of a belt is ok but one on the edge means replacement. |