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Discussion Starter #1 (Edited)
So my rear sprocket carrier is rubbing on the eccentric. Seems to have gotten worse over time. Any one here have any Ideas why.
I will post pics soon.
D
 

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Discussion Starter #2
pics

heres the pics
 

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The last 4 pictures are too blurry to make out. Likely cush drive bolts backing out. Do you see metal shavings on the rims?
 

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Discussion Starter #4 (Edited)
The last 4 pictures are too blurry to make out. Likely cush drive bolts backing out. Do you see metal shavings on the rims?

yes on the shavings
on the swing arm
I was thinking something like this but it is the carrier that is rubbing NOT the cush drives.
what do i need to do now?
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Did you just take the sprocket assembly off, and after re-install the problem occurred? Or did it just happen on it's own?

Same problem happened to mine after a certain dealership in the Santa Barbara area installed a quick change assembly on my 996. There is a washer that goes in between the eccentric and the sprocket hub/assembly. It spaces out the hub so it doesn't conflict with the eccentric.

It is very easy to forget to install the washer.

To me it doesn't look like the bushings are backing out because it looked like you have sprocket to eccentric contact. But those bushings can back out if not installed correctly.

Good Luck Bro.
 

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Discussion Starter #6
Did you just take the sprocket assembly off, and after re-install the problem occurred? Or did it just happen on it's own?

Same problem happened to mine after a certain dealership in the Santa Barbara area installed a quick change assembly on my 996. There is a washer that goes in between the eccentric and the sprocket hub/assembly. It spaces out the hub so it doesn't conflict with the eccentric.

It is very easy to forget to install the washer.

To me it doesn't look like the bushings are backing out because it looked like you have sprocket to eccentric contact. But those bushings can back out if not installed correctly.

Good Luck Bro.
Happend on its own. spacers and all other hardware in order. Im starting to read about cush drive faileur and im leaning twards that. any opinions?
 

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Cush drive failure?

Do you mean the bushings that sit inside the inner sprocket and attach to the hub assembly? The second photo shows that the contact is with the inner sprocket and the eccentric. Doesn't appear that the bushings re contacting the eccentric at all.

Maybe your hub is junk. Are you positive that the washer was installed?
 

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Discussion Starter #8 (Edited)
Cush drive failure?

Do you mean the bushings that sit inside the inner sprocket and attach to the hub assembly? The second photo shows that the contact is with the inner sprocket and the eccentric. Doesn't appear that the bushings re contacting the eccentric at all.

Maybe your hub is junk. Are you positive that the washer was installed?
positive about washer. Again carrier is conecting with eccentric. I dont see how a hub issue could cause this.
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Discussion Starter #9
look at these shots of the cush drives

the cush drive are not bottomed out in to the stm carrier. I wonder it this is a problem. Thoughts and Informed opinions please.
D
 

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Maybe we are getting our terms mixed up.

Thats my best idea. Otherwise I'd check the circlip on the carrier assembly, maybe it came unseated. Is there play on the splines? Could there be a problem on the eccentric side, where the washer I'm talking about seats on the the eccentric hub?

Whatever it is, you obviously have a spacing issue.

Just ideas. Looks like you prob pretty pissed by looks of those photos. I know I was.
 

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the cush drive are not bottomed out in to the stm carrier. I wonder it this is a problem. Thoughts and Informed opinions please.
D
Take it apart and you'll see. The bushings have collars on them that are slightly different heights. Which is why you they all appear to have different spacings relative to the carrier.
 

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Discussion Starter #12 (Edited)
Maybe we are getting our terms mixed up.

Thats my best idea. Otherwise I'd check the circlip on the carrier assembly, maybe it came unseated. Is there play on the splines? Could there be a problem on the eccentric side, where the washer I'm talking about seats on the the eccentric hub?

Whatever it is, you obviously have a spacing issue.

Just ideas. Looks like you prob pretty pissed by looks of those photos. I know I was.
eccentric is fine.
cir clip is fine.
Spacing was fine (this issue developed over time.)
look at the photos of the cush drives. should they be seated further into an stm carrier? Because there is that little lip on the inside of the carrier and the space diference is the same amount that the cush sticks out on the front.

Here are some more photos. I made some changes so that I don't look so pissed off.
D
 

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It looks like the carrier has stops for the cush drives. If that is the case, that isn't your problem. It doesn't look like it is the problem to me either. Has your eccentric moved out of the swing arm a bit? It is hard to say from the fuzzy pics that you included. The carrier itself is what looks like it is rubbing on the eccentric. I hope you figure out what the issue is.
 

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eccentric is fine.
cir clip is fine.
Spacing was fine (this issue developed over time.)
look at the photos of the cush drives. should they be seated further into an stm carrier? Because there is that little lip on the inside of the carrier and the space diference is the same amount that the cush sticks out on the front.

Here are some more photos. I made some changes so that I don't look so pissed off.
D
I see what you are saying.

If the sprocket was spaced further to the outside of the assembly you would get some distance away from eccentric. Thus no contact. But I'm not sure thats your problem. I don't have my bike in front of me, but I thought that the spacing was determined by the eccentric-washer-carrier relationship.

I would take apart the carrier. Re assemble with a little lube (wd40) make sure that the bushings aren't binding and position the sprocket so the bushings rest against the inside stops on the sprocket. (almost flush to the backside)

That will solve your problem for now, but the real question is what allowed the sprocket to work in the contact the eccentric? How long/miles had the assembly gone without inspection/removal?

This is making me re-assess my issue. Let me know.
 

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Ok, I couldn't sleep.

So I did some more research. Looked in some old threads on this forum and found some microfiche from Ducati of Omaha. Take look at the diagram for the complete rear assembly (officially called the rear wheel pin) and you will see that there are more washers involved that might have been left out from the original install of the quick change setup you have.

When looking at your hub pictures I noticed that there wasn't a washer behind the cir-clip that holds the sprocket assembly together. There should be one. It's labelled #6 I'm pretty sure.

I would disassemble the whole thing and reference the link I have posted and try to get the bottom of it. I'm gonna take mine apart too. Make sure everything is hunky dory. If you have the original install instructions from whoever made the your quick change setup that might help as well.

Now I can sleep.

http://www.ducatiomaha.com/products.asp
 

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I had this happen to mine, you may have the same issue: the circlip had 'eaten' away in the groove meaning the whole assembly had moved in and started grinding the swingarm.

I swapped to the later 998 style sprocket carrier that does away with the circlip part and has a tapered bush instead - you can buy the complete assembly, or just the bush and machine down your old carrier, you could even make the tapered bush if you have access/skills to a machine shop (I have the measurements) this completely prevents it happening again.

Swingarm/eccentric showing wear;



Old carrier with worn circlip groove;



New style carrier complete;



Tapered bush of new carrier;



HTH
 

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Discussion Starter #18
Stm carrier photos please

OK im going to get back to it here. If some one has a photo of an stm carrier assembled and funtioning corectly please post it up.
D
 

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Discussion Starter #19 (Edited)
a closer look and more questions

here are some shots of the hub and the sprocket carrier. Im wonering about the large bushing in photos 1 and 2. should that be in further?

Also if the popular theory about the circlip goove beiing worn is correct shouldnt there have been some free play?
D
 

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The plain bearing should be a flush fit in the carrier the way you
have it now is not correct.
when you fitted the hub through the carrier to fit the large circlip
it must have been hard to get the c/clip on with the shim/washer behind the
circlip ?.
If you tap the plain bearing flush it will let the stm carrier move to the correct
position when the hub is fitted through and the shim/washer and large circlip is fitted.
The stm carrier you have has webs on the back of the cush drive holes to stop the cush drives from backing out so no problem with that.
The hub with the circlip/washer set up is the older design the one dukedesmo has shown is the newer design which is much better and you need a new version hub (or mod your old one), as it no longer uses the circlip/washer shim set up just the large tapered
washer.
with the circlip set up you will get a small bit of movement when its all fitted together.

brian.
 
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