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After reading many of the threads about belt noise, chirping and rubbing, I am somewhat convinced that it may be a problem with belt alignment/adjustment. My 900LT only has about 3k on the clock, but I have been watching the rear belt and pulley closely. The belt has never wobbled or been noisy, and I have put many 10’s of thousands of miles on other belt drive bikes with no noise or problems. The belt on the 900 during this time has maintained a constant .028” space between the belt and outside lip of the pulley and a .040” space on the inside lip. The left axle mark is at 3 and the right is 2.5. Marks are not reliable.

I have borrowed the below from a site called OverRacing. It is not my writeup and I believe in giving credit where credit is due. I have used both methods or similar over the years with both chain and belt drives and have never had a problem. This guy knows what he is doing and talking about.


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Belt/wheel alignment method 1:

First measure from the center of the swingarm pivot to the center of the axle. Keep it the same on each side. I have Been doing this on dirt bikes for many years and has not failed yet. Adjust belt at tightest point. I use the Motion Pro belt tensioning tool.


Belt/wheel alignment method 2:

This is what I do if I change a tire or belt.

1] Loosen adjusters completely slide tire to front of adjustment slots.

2] Run in both adjusters till they just touch

3] Count threads to make sure they are even

4] Going 1/2 turn per side. Take the belt to just loose of adjustment

5] Tighten axle nut and spin wheel about 10 times, to check belt tracking.

6] If belt is too far right loosen the axle tighten the left side an additional 1/2turn. Opposite for belt too far left. Spin wheel again and recheck. You will never get the space between the belt and pulley lip exact on both sides.

7] Tighten both sides equally until you have 9mm of deflection at 10Lb force. At the TIGHTEST point. The belt has tight and loose points.

At this point I test ride. I have NEVER had to go back and readjust doing it this way, and I have done MANY without a tracking problem. No strings or tape necessary

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Thanks Ash, for taking a further interest in this subject. I will use the advice as/when I tighten her up.

Denis
 

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Discussion Starter #3
One other thing I failed to mention. If the belt is overtightened or misaligned it will stay stretched in that position. It is not a rubber band. You may never get the noise out and will decrease the life. Do it right the first time.
 

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Now he tells me! I guess learning from the mistakes of others is all well and good, but learning from your own mistakes is even better.
 

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Discussion Starter #5 (Edited)
Dear ashtavakra,

Biohazzmat has just replied to a thread you have subscribed to entitled - Proper

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Now if I lean to the right all quiet and smooth. If i lean to the left I get a
vibration. I change the pulley 2 weeks ago and cant get belt right. Seems as if
tension is right but now I get the issue above.

Any suggestions?

Frank

Frank,

First check to see if all swingarm bearings are tight and smooth. It does not sound like an adjustment problem to me, but an alignment problem.

A misaligned belt will wobble and vibrate, and as you ride through the twisties and as the swingarm flexes it may get better and worse.

The best way to check alignment, though the most time consuming because you will have to remove the mufflers/pipe/covers etc., is to measure from the center of the swingarm frame pivot bolt to the center of the rear axle on both sides and compare and adjust.

In the past on other belt bikes, I have used a brazing rod, bent it 90 degrees on one end(the swingarm end) and to the length needed to get it to lay
across the rear axle. At the axle end I put a adjustable bead, so I can slide it up and down the rod.

Place rod on one side, put elbow end to center of swingarm pivot bolt, lay rod across rear axle and adjust bead to center of rear axle. Repeat on other side, they should be the same.

Then do your tightening procedure, remembering to adjust both sides evenly.

If the belt still wobbles around on the pulley and vibrates, then the belt has been stretched unevenly by misalignment and is junk.

We all look for shortcuts, but sometimes the seemingly long and hard way is the best.

Cam
 

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Apparently I fell asleep last time i made the alignment adjustment. The right side was way off from the left. Evened them out and the rumble (or whatever) seems to be gone.

I'm taking her out in a bit so will know for sure.

Thanks for help.

Frank

Sometimes I seem to not see the forest through the trees.
 

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Discussion Starter #7
Now he tells me! I guess learning from the mistakes of others is all well and good, but learning from your own mistakes is even better.
+1 I learned my mistakes on chains. After ruining a few sets of sprockets/chains it finally dawned on me that there must be a better way. You are a philosopher, life is the same.
 

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Now he tells me! I guess learning from the mistakes of others is all well and good, but learning from your own mistakes is even better.
...right... :( I dare say I jinxed my belt. Squeaky shoe sound... I had it from "automotive engine belt tight" to 'finger pressure will nearly take the belt out of the little window" and that daym sound won't go away.:mad:

EDIT:
I did the "measure from bolt to swingarm (on belt side I had to remove the chrome cover on the side of the engine/gearbox) to axle" thing to ensure alignment with belt tension similar to what I have on my Jeep (about 1/2 inch pushing firmly with a couple fingers), and it squeaked a little. A half turn loose and judging by my down the street 25mph ride, all is well. :) :)
 

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I`ve noticed a few things. When it`s hot outside the noise is there when it get`s cool it`s gone. As well, the more weight on the bike the better. Analysing this last point, I measured things. The more weight...the looser the belt. I didn`t consider my belt tight (about 7 mm play more than Kawi`s 4 mm for a used belt) with the weight more like 9-10 mm. Food for thought...

Denis
 

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Hi ashtavakra
Thank you for your post regarding the method of rear wheel alignment. It certainly made sense to me that if the distance between centre of the swing arm pivot bolt and the centre of the rear axle bolt is the same on both sides then the rear wheel must be correctly aligned.
I live in Australia and own a VN900 Classic. I have just had to replace the belt at 18,000km due to stone damage [thanks to the gravel roads that are common in this country].
When I installed the new belt I followed your advice and made a steel rod with pointers as you described. I then used a centre punch to mark the centre of each end of the swing arm pivot bolt and to give the pointer an indent to fit into.
However, I found the rear axle bolt of my 2013 VN900 is actually hollow. To overcome this I purchased a piece of bright mild steel bar [rod] that would slide neatly into the hollow shaft from the drive belt side. I then discovered the steel rod would not go all the way through the hollow axle as the hole is not parallel throughout the length of the bolt. The hole at the nut end of the axle is slightly smaller. However, this was not problem as I simply purchased another piece of mild steel bar of a smaller diameter that would slide neatly into the axle from the nut end.
After cutting each of the two pieces of steel bar rod to an appropriate length to allow a small amount to protrude from each end of the axle I then marked the centre of each to give the other pointer an indent to fit into. With the swing arm pivot bolt and the rear axle ate the correct tension it was then possible to measure the distance on both sides with great accuracy.
I have since taken the bike on a 1600km ride and the belt runs perfectly.
Thanks for your excellent suggestion of making a measuring bar. With slight modification it worked perfectly for me.
Regards
VeeMax
 
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