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Discussion Starter #1
After reading about a multitude of belt issues and adjustment problems on this forum (one poor guy was thinking of selling his Thunderbird because of all the belt horror stories he read), the time came to adjust my belt. I had gone past the recommendation of adjusting at 2,500 and took it to 5,000 because even though on the loose side, the belt was performing well. Absolutely no noticeable wear, no chirping and the belt always ran to the outside flange of the wheel pulley. I decided to do everything by the manual the first time, just to see where that got me. Before starting, I bought the belt tension gauge and the wheel alignment tool from Triumph

Prior to adjusting, I measured the wheel alignment using the alignment tool, just to see where the factory had it set. The measurement was 3.048” on the left and right sides. I then tightened the belt, but this is the only thing I didn’t do to factory spec. They recommend a maximum deflection of .350” and I came in at .375, simply because 3/8” was easy to read on the deflection gauge and I decided to err a little on the loose side, since the belt will loosen with use anyway. The wheel alignment wound up at 3.094” on each side. I tightened everything up to factory torque specs, put it all back together and went for a ride. Not surprisingly, the belt performed smoothly, did not chirp and continued to end up against the right flange, just like it did from the factory. I only took a 50 mile ride, but if it goes sour over the next couple of thousand miles, I’ll update this thread.

During the procedure, I inspected every inch of the belt with a high intensity light and it is still looking like new. There were some very slight rub marks (no noticeable wear) on the right edge, not surprising because the belt does rub against it.

On the issue of where the belt is tracking, I think these belts are designed to ride against the flange and trying to get it to ride in the middle with a 1/16” gap on each side is a waste of time. Mine has been against the outside flange for 5K, still looks great, doesn’t chirp and is not showing edge wear. It continues to ride the right flange just as it did from the factory.

On the issue of chirp, I think that this is caused by a belt/pulley misalignment, just as it is in autos. If a belt contacts the edge of the pulley at enough of an angle, it rides up the edge then snaps back down, causing a chirp. This happens quickly and repeatedly, making it sound like you have birds in your back wheel. My guess is that often times, the rear wheel is improperly aligned after belt tightening and the dreaded chirp begins.

This procedure worked for me. If you are having chirp issues, I suggest that before you spend a lot of time and/or money you might want to try and set everything back to the factory spec and then work it from there. Also, I don’t have a clue as to how to check belt alignment unless you have a laser belt alignment tool. I’ve seen these for as low as $50 but can’t vouch for how effective they are.

As always, this is just my experience and opinion. I hope you find it useful.
 
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Discussion Starter #3
Didn't even look as I used the vernier calipers for the measurement. I'll check it out and get back to you.
 

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Discussion Starter #4 (Edited)
I am curious as to what the measurement between the alignment marks on your swing arm are.
Don't know if this helps, but the v-notch in the axle adjuster lines up under the third hole from the front on each side. This will vary depending on how much your belt has stretched. Obviously, the important thing is that they are aligned equally on both sides and I don't think you can do an accurate job of this without the alignment tool and a vernier caliper. The marks are large enough that they could appear equal but still be several thousandths out.

This alignment tool is only about $35 and I found it easy to use and accurate. Decent (good enough for adjusting belts) vernier calipers can be had for under $50 on Amazon. Fast Eddy will sell you a belt tension tool for $30. For about $115, you're good to go and I'm guessing a dealer would hit you at least $150 - $200 each time they adjusted the belt because to align the wheel properly, you need to drop the mufflers.

By the way, all of my adjustments were done with the rear wheel off the ground. I personally don't think you can get an accurate adjustment with the bike on it's side stand. I just used my trusty Sears motorcycle jack.

I'll update this thread at +500 and +1000 miles after the adjustment to let you know how the belt is performing using this technique.
 

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BigGuy,

Thanks for this reasoned post. I too have. 2012 Bird with about 5000 on the clock. My belt consistently runs to right and has not yet been adjusted. It too is a bit loose but seems to perform well and has no noticeable signs of wear or defect. I'm likely to buy the necessary tools and put mine up on the Sears lift to do the adjustment myself. I'll keep an eye out for your post as the miles mount. Thanks again!
 

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Don't know if this helps, but the v-notch in the axle adjuster lines up under the third hole from the front on each side. This will vary depending on how much your belt has stretched. Obviously, the important thing is that they are aligned equally on both sides and I don't think you can do an accurate job of this without the alignment tool and a vernier caliper. The marks are large enough that they could appear equal but still be several thousandths out.

This alignment tool is only about $35 and I found it easy to use and accurate. Decent (good enough for adjusting belts) vernier calipers can be had for under $50 on Amazon. Fast Eddy will sell you a belt tension tool for $30. For about $115, you're good to go and I'm guessing a dealer would hit you at least $150 - $200 each time they adjusted the belt because to align the wheel properly, you need to drop the mufflers.

By the way, all of my adjustments were done with the rear wheel off the ground. I personally don't think you can get an accurate adjustment with the bike on it's side stand. I just used my trusty Sears motorcycle jack.

I'll update this thread at +500 and +1000 miles after the adjustment to let you know how the belt is performing using this technique.
Big guy I have been threw the by the book alignment at the dealer and even babysitting the techs didnt make my bike run without the chirp or excessive side wear.

I am not a beginner and dont need the tools I have everyting nessasary to do the job and then some and can simply borrow the triumph tool from the shop anytime I need to. Problem is using that tool on my bike creates the chirp and if you tighten the belt to spec and use the tool it causes excessive edge belt wear.

They made changes to the bikes and the distance between the alignment marks is the only way I know of to determine if your bike was built after the changes.
 

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Discussion Starter #7 (Edited)
Paulfun,

I misunderstood your question but I'll check this out and get back to you. I'm leaving on a business trip today, so I may not get to this until Friday.

Don't know if this helps, but mine is a 2012 w/ABS and as I said, using the procedure in the manual worked perfectly. Whatever change they made obviously worked. Must have something to do with the position of the frame tabs they use to measure off of, because this would be critical to squarely positioning the wheel.

I'll get back to you as soon as I get the measurement.
 

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Discussion Starter #8
Paulfun,

Got to read it before leaving. Hard to read accurately because the pipes are on, but looks like 3mm OC, 6 holes. Mine line up perfectly on both sides and the caliper confirms that.
 

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I have 34K on my 2010 tbird. I tension my belt to the Triumph spec. My belt has never chirped so my guess is thats caused by being too loose. I am a mechanic and work on lots of different kinds of industrial equipment. In that environment, the belts that vibrate and make noise are too loose. I have read some posts about that spec being too tight and you risk wearing out your bearings. Think about the tension on the belt when you start having fun with the throttle. If that don't mess up a bearing I'm convinced a 14mm adjusting nut won't do it either. Getting the tension in spec is simple compared to alignment.
I started out thinking alignment was simple. Just do it the same way as a chain driven bike using the alignment marks. Now, I believe that my marks are wrong and it would be very difficult to get it correct by eyeball. This is my first belt drive bike so I just assumed if I took my time and eyeballed it as close as possible it would be ok. The belt rode constantly on the outside flange and I left it that way too long. When I realised the flange was wearing the belt I got out the calipers. Now I believe the wheel is within .040" of being straight, the marks are useless, and belt wear is an indicator of misalignment. Plus or minus .020" will drive the belt from one side to the other. I ended up adjusting till the belt moved to both flanges when ridden. I would ride a few miles then stop and check. Sometimes the belt was on the inside and sometimes on the outside or somewhere in between. I then backed off by 1/12 of a turn and the belt stays on the inside edge. I use 6 edges and 6 flats of the nut for reference so 1/12th of a turn is easy and it makes a difference on where the belt goes. Now I assume the wheel is straight enough and thats the point of alignment (not where the belt is) and if the belt doesn't wear too much I don't care where it is. Time will tell. I'm going try it for a while on the inside.
 

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Discussion Starter #10
I have 34K on my 2010 tbird. I tension my belt to the Triumph spec. My belt has never chirped so my guess is thats caused by being too loose. I am a mechanic and work on lots of different kinds of industrial equipment. In that environment, the belts that vibrate and make noise are too loose. I have read some posts about that spec being too tight and you risk wearing out your bearings. Think about the tension on the belt when you start having fun with the throttle. If that don't mess up a bearing I'm convinced a 14mm adjusting nut won't do it either. Getting the tension in spec is simple compared to alignment.
I started out thinking alignment was simple. Just do it the same way as a chain driven bike using the alignment marks. Now, I believe that my marks are wrong and it would be very difficult to get it correct by eyeball. This is my first belt drive bike so I just assumed if I took my time and eyeballed it as close as possible it would be ok. The belt rode constantly on the outside flange and I left it that way too long. When I realised the flange was wearing the belt I got out the calipers. Now I believe the wheel is within .040" of being straight, the marks are useless, and belt wear is an indicator of misalignment. Plus or minus .020" will drive the belt from one side to the other. I ended up adjusting till the belt moved to both flanges when ridden. I would ride a few miles then stop and check. Sometimes the belt was on the inside and sometimes on the outside or somewhere in between. I then backed off by 1/12 of a turn and the belt stays on the inside edge. I use 6 edges and 6 flats of the nut for reference so 1/12th of a turn is easy and it makes a difference on where the belt goes. Now I assume the wheel is straight enough and thats the point of alignment (not where the belt is) and if the belt doesn't wear too much I don't care where it is. Time will tell. I'm going try it for a while on the inside.

I found that usually a misaligned belt chirped and a loose belt squealed. A toothed belt, of course, can't squeal, but I think that a misaligned toothed belt will chirp.

Paulfun seemed to think that the newer bikes had some sort of modification that could be identified by the spacing of the alignment marks, but I haven't heard from him after providing the measurement. Could be that because you have an older T'Bird you are having alignment issues.

The other thing that I noticed was that the belt seemed a little tighter once the bike was ridden hard, but it still wasn't as tight as other posters have observed (this was by feel only). While the pulley expands as it heats, the belt may do so also, keeping the relative tension pretty close to cold, but this is just a guess.

I put another 50 at highway speeds on today with no adverse effect and is still riding o the right flange. Obviously, 100 miles total after the adjustment is nothing, so after I get another couple thousand on the belt, I'll update this post.

Good luck with your method.
 

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Paulfun,

Got to read it before leaving. Hard to read accurately because the pipes are on, but looks like 3mm OC, 6 holes. Mine line up perfectly on both sides and the caliper confirms that.
Took a quick look today. A quick measurement on mine shows just over 5mm. A little hard to reach in there with the caliper I grabbed but they are definately different.
 

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Discussion Starter #12
Update

I mentioned earlier in this thread that I would update at 500 and 1,000 miles after the adjustment. The update is boring - the belt is still running against the right flange of the rear pulley, tension is fine, no damage and no chirps. Again, only 500 miles, but so far, so good.

Here's my theory on this whole belt issue. If the rear axle is perpendicular to the frame axis (as determined by measuring the axle against each side of the frame with vernier calipers as stated in the manual) and the belt rides on the right flange, then that's the way it's supposed to be. If you have to skew the axle to get the belt to float or ride the center, then the rear wheel is not properly aligned to the frame because it will not be perpendicular. Doing the adjustment this way might be the cause of chirping because it puts the belt at an angle to the flange. It also may cause tire wear? Don't know, but sounds reasonable,

This, of course, assumes that the engine pulley is also properly aligned from the factory. There's also been some speculation on this forum that older T'Birds can't be aligned properly with calipers because an equal reading on both sides results in problems. The thought is that Triumph may have somehow modified the machine to correct this. I can't speak to that, but I can say that so far, it seems as though the procedure detailed in the service manual works for 2012 models.
 

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BigGuy, did you also tighten the belt to spec? If so, I understood that the spec may be too tight. Any insight on this?
 

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Discussion Starter #14
BigGuy, did you also tighten the belt to spec? If so, I understood that the spec may be too tight. Any insight on this?
Yes I tightened it to spec (almost). The spec is .350 and I tightened to .375 (3/8") on a 10 lb. gauge because mine is in inches, not thousandths. This is just a tad loose. I've read the accounts of overly tight belts stressing bearings and I can't vouch one way or the other for that statement, but I elected to go with the spec just to see if that caused any weird noises or performance issues. I already know what the performance is like when the belt is run loose. In the future, I'll go to a 1/2" deflection, because a little loose can't hurt.

The point here is that by going with the factory spec, my bike (and particularly the belt) is performing well without any noticeable downside. I'm sure that eventually the belt will wear, as is normal. The key, of course, is how far along that occurs.
 

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Someone posted a pic of thier brand new bird elsewhere and there is a pretty big (bigger than mine) gap between the belt and right side. In fact, the belt appears to be against the left flange. The adjuster also appears to be different than on my bike which is one of the first. So they definately seem to be changing things.
 

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Discussion Starter #17
Someone posted a pic of thier brand new bird elsewhere and there is a pretty big (bigger than mine) gap between the belt and right side. In fact, the belt appears to be against the left flange. The adjuster also appears to be different than on my bike which is one of the first. So they definately seem to be changing things.
Don't know ... can only say my procedure worked for me. However, I'd like to see that pix .. do you remember the thread it was in?
 

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I can't link to it or my post will be deleted and i'll get banned. But i saved it, cropped it and zoomed it and this is the result...

 

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Discussion Starter #19 (Edited)
Someone posted a pic of thier brand new bird elsewhere and there is a pretty big (bigger than mine) gap between the belt and right side. In fact, the belt appears to be against the left flange. The adjuster also appears to be different than on my bike which is one of the first. So they definately seem to be changing things.
I checked mine after you posted the picture and the adjusters on my bike are the same. Also, I did a 200 miler today and checked the belt a few times during the trip. Always wound up against the right flange. I'm guessing that it probably doesn't matter where the belt rides, as long as the rear wheel is perpendicular to the frame axis. If the belt is riding inside and parallel to the pulley flanges, there should be no problem where it rides. Maybe where it rides is determined by where the engine is set at the factory ... I'd like to think they are all the same, but that's obviously not so.

I'll be keeping an eye on it to see how the belt holds up. So far, 800 miles since the adjustment and all is well.

By the way, I'm thinking of buying the chrome pulley ... it looks a lot nicer than that aluminum does.
 

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Mine looks different. Mine is a 2012, but the adjuster is one solid piece of metal with a threaded hole the adjuster screw turns into. Is the picture you posted dazco your older bike or a newer one?
 

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