Weird popping noise from back wheel (Solved?)

EEL · August 12, 2008, 09:04:08 AM

05 S2R 800

I think I have a potentially serious problem - Getting a weird popping noise from the back wheel when the bike is moving. At first I thought it was the chain but I lathered it up with grease and its still popping. I'm getting worried that it might be some kind of bearing inside the eccentric hub.BTW - my cush drives are fine nothing backed out as some people have experienced. I took a quick check and they look fine.

To be sure, I want to disconnect the chain from the rear sprocket and roll the bike around. If it still pops, its either something inside the tire or the hub.

What I'm looking for confirmation on a couple of questions:
1) Is there enough room to wiggle the chain off the rear sprocketin such a way that I dont have to break a link or remove the chain completely to perform this test.
2) I'm assuming there is some bearing mechanism inside the eccentric but I dont know anything about the internals. Someone provide some input. The service manual only shows how to remove the eccentric, I didnt see anything on how how to take it apart.
3) Any ideas on what else could be causing the problem right now my best hope is the chain itself. But I dont want to jump to worst case scenarios but I can guarantee that the noise is coming from the back wheel. I'll try to record the sound and post it, though this will take some creativity on my part.

hypurone · August 12, 2008, 09:24:50 AM

I would first check both the axle nuts. Left & Right side for the wheel. I just did a 520 swap and the LH nut was loose!! HOLY SHIT!!

Speeddog · August 12, 2008, 09:25:13 AM

Have an assistant roll the bike around while you watch and listen.

How many miles on the chain?
They can be worn out to the point that external lubrication will not help.

Does it have kinked links?
Dark red rust color coming out between the plates?

ducpainter · August 12, 2008, 09:37:13 AM

Also check for cush drive rubbers backing out and hitting the swingarm.

EEL · August 12, 2008, 09:41:42 AM

I'll throw a pic of the chain for all to see. Chain doesnt have too many mles on it. Maybe about 10k I've run chains to the ground before so I'm familiar with the red rush, I havent see that yet on this one. I dont feel any kinking either and its wearing pretty even, no significant loose spots.

I just want to eliminate the eccentric hub first. Then I can breathe a sigh of relief.

If it is the chain, I'll probably just run it to the ground and deal with the noise. The next chain replacement will require new sprockets anyways.

Speeddog · August 12, 2008, 10:01:36 AM

You may be able to turn the eccentric far enough to slip the chain off.

EEL · August 17, 2008, 01:50:13 PM

Ok, guys this is REALLY weird. I was hoping it was the chain but its NOT. I took the chain off from the rear wheel, completly eliminating it from the equation. Wheel still pops and the noise has been getting is getting louder of late.

Now here's the really weird part. If I put it up on a SSS rearstand and spin the wheel in the exact same direction, I get absolutely no popping. I dont feel any kinking or rough spots so I'm thinking that its not the bearing inside the eccentric. I also took off the plastic chain guard at the rear wheel to no avail thinking it might be the issue.

I did get a tire change of late on the rear wheel. Anyway it could be this??? I'll post a video shortly of both situations; on the ground and on the rearstand.

DarkStaR · August 17, 2008, 02:30:18 PM

Hey ELL,

Has the noise changed since the last time I heard it?

This sounds like the same issue your having:

http://ducatimonsterforum.org/index.php?topic=3061.msg44097#msg44097

Maybe you can following up with him/her to see what it was.

Capo · August 17, 2008, 03:05:20 PM

Quote from: EEL on August 17, 2008, 01:50:13 PM
Ok, guys this is REALLY weird. I was hoping it was the chain but its NOT. I took the chain off from the rear wheel, completly eliminating it from the equation. Wheel still pops and the noise has been getting is getting louder of late.

Now here's the really weird part. If I put it up on a SSS rearstand and spin the wheel in the exact same direction, I get absolutely no popping. I dont feel any kinking or rough spots so I'm thinking that its not the bearing inside the eccentric. I also took off the plastic chain guard at the rear wheel to no avail thinking it might be the issue.

I did get a tire change of late on the rear wheel. Anyway it could be this??? I'll post a video shortly of both situations; on the ground and on the rearstand.

When you rotate the rear wheel on the stand, it is turning on the bearings in the stand not the bearings within the eccentric.
Ducati state in the manual that it is forbidden to disassemble the eccentric this is probably due to the special bearings. Only sold as an assembly, it 'aint cheap. One on ebay UK for about $150.

Get the rear wheel off the ground with the suspension unloaded then spin it.

You might want to check that the rear wheel is located on the drive pins correctly, it is possible to fit it incorrectly.

DarkStaR · August 17, 2008, 03:11:44 PM

Quote from: Capo on August 17, 2008, 03:05:20 PM
When you rotate the rear wheel on the stand, it is turning on the bearings in the stand not the bearings within the eccentric.
...

^That doesn't make sense.^

If the wheel is turning, then the axle is turning, and the bearings in the eccentric are turning.

DucLeone · August 17, 2008, 04:42:28 PM

while pushing it around you sayd it pops ,
once it pops >stop> roll back , does it pop at the same place?

EEL · August 17, 2008, 06:30:41 PM

Does not pop in the same place. Its completely different every time. Sometimes it doesnt pop at all.

I think its my new tire. Thats the only thing it could be. Thats the only thing that could explain the fact that it doesnt pop when its on a rear stand. I think its because I'm loading the bearing and not the tire, hence no popping. Then when I put in on the ground and load the tire, it pops. It might be a defective bead on the tire, somehow not seating properly or something.

Dark, are per your earlier question, sounds exactly the same.

EEL · August 17, 2008, 08:01:53 PM

I uploaded some videos on my server (See Link Below). One with sidestand and 2 with the popping noise. I'm thinking its the tire right now..

Let me know what you guys think

Videos of Popping Noise

DucLeone · August 17, 2008, 08:38:55 PM

sounds almost like someting is fliking the tire
(maybe a ripping belt inside the tire?

)

DarkStaR · August 17, 2008, 10:17:00 PM

ELL,

Can you take it back to where the tires were installed. Just tell them it started AFTER THEY worked on the bike. If it's the tire, then go for the warranty. If not, then you'll know it not the tire. Depending on the shop, they might not charge you any $$$.

Also, since I recall you changing the rear caliper, have someone hold the caliper to ensure it/or the bracket is not the source of the sound.

Next step would be to take shit apart until it stops (i.e., sprocket carrier). Then you can make an educated guess that the last part removed was the cause of the noise.

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Weird popping noise from back wheel (Solved?)