Compensator front sprocket assembly

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Compensator front sprocket assembly


Post by lockdoc » Fri Nov 30, 2007 5:50 am

I'm considering converting my primary back to chain from the belt drive it came with. The only thing I don't understand since I haven't had one is the compensator front sprocket assembly. My factory manuals just brush over it and have no pics. Can someone explain in detail what it is and the function it provides? I found pics of the assembly but can't figure out it's purpose. I have a 65 pan engine without electric start. Kick only. Thanks a lot!

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Post by Cotten » Fri Nov 30, 2007 12:54 pm


The compensator absorbs the shock of the chain going slack and tight. They are pretty important with a sidecar or heavy payload, but a light machine can run a plain sprocket with no problem at all.

The compensator's sprocket has ramps on it that correspond to opposing ramps on a sliding "cam". A large spring pushes the two together. When the chain suddenly goes tight with accelleration, the ramps can 'walk' up on each other against the spring tension, thus absorbing shock.

The '55-'69 compensators are hard to find with an un-worn sprocket, however 24T units are now in the repop catalogs (quality unknown.)
23T were stock for solo machines, and 22T for sidecar duty.


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Post by lockdoc » Fri Nov 30, 2007 2:00 pm

Just the kind of info I was looking for. Thanks a lot!

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Post by DuoGlide62 » Fri Nov 30, 2007 4:33 pm

If a picture is worth a thousand words here's my speech.
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Post by lockdoc » Sat Dec 01, 2007 12:38 am

I love pics! Thanks. I'll assume that the last piece in the setup furthest from the sprocket acts as the nut on the main shaft and the 4 smaller holes are for a tool to fit into to loosen and tighten?

While I'm showing my ignorance I'll also ask about the double sprocket. I have come across setups that show the double sprocket but the sprocket on the clutch drum appears to be single. What am I missing?



Post by Guest » Sat Dec 01, 2007 2:11 am

Lockdoc, I got a total perfect unit sitting here on my bench. $40.00 plus shipping its yours! Bob

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Post by biker_k » Sat Dec 15, 2007 7:05 pm

that you need to shim the compensator assy for preload on the spring. If you don't, you'll have nothing but pure slippage when you apply any throttle. I made the mistake of not installing shims and after a new clutch and many hours of scratching my head.......I finally rode around the block with the primary cover off. It was apparent what was going on the second I applied throttle. Then realizing that there are many knowledgeable folks here, I realized what those shims were sitting in my toolbox. I opted for replacing the compensator for just a straight sprocket as my chopper is very light and the performance without compensator is just fine. I am however, considering putting it back on though. I could not find any mention anywhere of how much preload that you need on the compensator though. So, I guess you just go by trial and error.

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Post by fourthgear » Sun Dec 16, 2007 4:45 pm

You could be referring to a starter ring gear on the clutch drum(shell ) of an electric start clutch drum(shell ) or a non- big twin clutch drum(shell ) some use them on kick only bikes also. The primary drive chain sprocket is on the back side of the clutch drum (shell ) kinda out of sight when all together and looking at it.
I believe NOS parts has most of the system (compensator ).

I would be interested if lockdoc is not ,in the compensator system .



Post by Guest » Sun Dec 16, 2007 9:09 pm

Now its time for you guys to ansewer a queation that always bugged me. Why did some models come with the compensator where others had the fix motor sproket? Was it a dealer upgrade? No ones ever ansewered this one. Fourthgear, It's still sitting on my conference table asking me daily four a new home. I orignaly got it with the intentions of putting a piece of braded leather though it and using it as a mase on my ex-wife. :P This is the shovel one and is 23 teeth if I remember right. Bob

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