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Message started by nicka on 06/06/09 at 13:56:52

Title: Drive Belt Chirp
Post by nicka on 06/06/09 at 13:56:52

The belt on my 2003 Savage chirps badly under power. I bought it with 2,700 miles on the clock and a quiet belt. But the belt started to chirp within a couple of hundred miles and has steadily worsened since. Serowbot rode it and it was so loud to him that he thought something major mechanical was happening. We carefully aligned the rear wheel so the belt ran centered on the rear sprocket, checked for proper tension. We then talcum powdered the belt; this increased the noise about 5 fold, so it was the belt. Close inspection of the belt revealed that it was very shiny (glazed?) on the top of the teeth and on both sides and the front of the teeth to about 1/3 depth on the front engaged by the front sprocket under power. The cogs showed wear on the top and faces of the teeth and on the retaining plates on the sides. We cleaned the belt, attempted to reduce the glaze with abrasive and then sprayed it with PrimeFlo silicone lubricant. This effected a total cure; which lasted all of 5 miles. I then wire brushed the belt with strong detergent. It still chirps, but not quite as badly as before we started - but it is steadily getting louder. Various blogs on the internet reveal that chirping is a rare but recorded problem with Harley drives, no effective long-term cures being reported.

I am a serious cyclist and am very familiar with the problems associated with chain stretch and cog wear. So I made measurement of the belt; ten teeth for 5 ½ inches, ie tooth pitch of 0.55 inches, depth 0.205 inches. Measurements of the cogs is not so easy but I think they are for the rear a tooth pitch of 0.535 inches with a depth of 0.255 inches and for the front a tooth pitch of 0.525 inches and a depth of 0.22 inches. All measurements made with a vernier gauge at the top of the teeth.

I am ignorant of the theory of cogged belt design so the following are just my thoughts on what I think may be happening. As the drive tooth rises to meet the belt, its rounded corner meets the rounded corner (or even possibly the top) of the belt tooth. The belt tooth slides against the rising cog tooth (or maybe even drops off the top of the cog tooth before sliding) until the top of the cog tooth is in contact with the belt between the belt tooth and the next belt tooth. As the belt is wrapped around the drive cog, the belt tooth pitch is significantly reduced, probably to very close to that of the cog teeth as it is a nice snug fit. This wrap effect maybe why the rear cog has a wider tooth pitch than the drive cog (but still less than the belt) as the larger diameter of wrap would not reduce the belt tooth pitch as much as is needed for the drive cog.

I surmise that the chirping is caused by the belt tooth as it slides (or pops off and slides) against the rapidly rising cog tooth. This is a very severe environment for any lubricant, which is why silicone spray only lasted a few miles and why the effect of removing the glazing was also short lived. I guess that the chirping problem is not very common as it is the result of either a stretched belt or one that was at the outer end of the manufacturing tolerance.

I would be very interested to hear anyone else’s thoughts or suggestions. I will experiment with various lubricants over time and, if none is of lasting success (lasting being, say, oil change intervals) I will change to chain drive - much cheaper than a new belt and the ratios suck for a one up 120lb rider!

Title: Re: Drive Belt Chirp
Post by serowbot on 06/06/09 at 14:11:11

Hi Nick,
Hunting around a bit, I found this link on a Bonnie forum.... haven't read the whole thing yet but I thought you be interested....
http://www.bonnevilleamerica.com/forums/showthreaded.php?Number=232095

o.k., I read it.... Strangely enough, consensus there, is tighten the crap out of it.... consensus here, has been to loosen it...
Seems to me, just make it different than it is currently.. I'm wondering about turning it 'round and running it the other direction?... bugger of a job just to find out though...

Title: Re: Drive Belt Chirp
Post by High-Def on 06/06/09 at 14:23:34

Wish I had seen this earlier. Yep had the "chirpy belt"about a month ago. I checked the tension and it DID need tightened, tightened it, no more chirp. :)

Title: Re: Drive Belt Chirp
Post by Rocco on 06/06/09 at 20:02:49

mined squeaks a little bit, not sure if it's the wheel or belt, but i noticed it while riding and thought something was wrong. then i was walking the bike while off around the house and it churped only a little bit.

my backfire covers up the churp though hahaa

Title: Re: Drive Belt Chirp
Post by nicka on 06/06/09 at 22:25:18

I was cruising the Kawasaki forum and found that drive belt chirp is quite common on the 900 Vulcan; Dupont Teflon multi-use dry wax lube was recommeded. Bought a can at Ace, I will try it and post results.

Title: Re: Drive Belt Chirp
Post by justin_o_guy2 on 06/07/09 at 02:49:55

I have some canning wax & I apply that to the belt & that solves it for a while. Its real easy when its good & warm out. The stuff melts pretty good & I can pop off a small chunk & roll it like play do into thin strips & they stick here & there in the belt & on the rear cog, solving the squeak issue. Wax doea get slung off & hit the rear wheel, making a mess, but I dont care any more. It Rides nice, so I do it.

Title: Re: Drive Belt Chirp
Post by Phelonius on 06/07/09 at 10:02:50

The best way to adjust the belt so that it does not chirp is to place the rear wheel pully in the corner of your garage and the engine pully in another corner and the belt somewhere else. When they cannot even see each other they can not chirp.
Put sprockets and chain on the machine and be happier.

Phelonius

Title: Re: Drive Belt Chirp
Post by verslagen1 on 06/07/09 at 10:16:35

There are several factors that cause belt chirp, alignment and moisture are but two.

You have to have the belt aligned on the front pulley and rear pulley.

Rear pulley alignment, lift the rear wheel off the ground. With the bike in neutral, rotate the wheel by hand. Observe the belt, is it running in the center or to one side? Adjust as necessary. Now rotate the wheel in the opposite direction, same as before.

Now this is assuming you have a stock belt configuration in good shape and everything in the correct place.

If the belt is not running true in the front pulley, make sure you have the rear wheel spacers on the correct side.

If the belt can't be made to behave in the rear pulley I would suspect the pulley bearing, or the rubber dampers.

Title: Re: Drive Belt Chirp
Post by nicka on 06/08/09 at 22:03:01

The belt runs true on the rear sprocket. I will try to check the front tomorrow. But I doubt that anything has ever been done to the bike; it was barely run in when I bought it and everything was stock. So, unless Suzuki set it up off, it is probably straight.

Title: Re: Drive Belt Chirp
Post by Skid Mark on 06/09/09 at 07:00:07

I've rubbed the edges of the belt with bees wax. Doesn't make a mess and gets the squeek out. I give the belt an application 1 or 2 times a week ( I use the bike every day to commute to work) and this kills the chirp. I don't do the whole belt. I rub what edges I can get at each time. This works and has a minimun of fuss.

Title: Re: Drive Belt Chirp
Post by stratman on 06/10/09 at 01:16:50

I'm glad someone else hears a chirp. I couldn't figure where in the hell it was coming from!

Title: Re: Drive Belt Chirp
Post by Genjuro on 06/10/09 at 21:58:46

I used STP belt dressing on mine....works well.
You can get it at an auto parts store.

Title: Re: Drive Belt Chirp
Post by Digger on 07/02/09 at 21:44:24

Nicka,

If nothing else works, you can recheck your rear wheel alignment....check out this accurate and cheap rear wheel alignment tool:

http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1183995917

And, if the belt is still chirping, you can try this stuff:

Dry Moly Lube (http://www.crcindustries.com/auto/content/prod_detail.aspx?PN=03084&S=Y)

This stuff is high quality and they say it is safe for rubber belts. I got mine at the local Fastenal store.

IHTH!