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Riding my 2000 F4 (22k miles on her) home the other day and felt something odd. I stopped to check it out and found small metal particals (aluminum) on the rear rim. My first thought was that one of the rubber cush bolts backed out and rubbed the hub (happened on my 748) but they checked out OK.

I checked and replaced the rear break pads (they needed it any way) Went for another short ride and more glitter on the wheel.

I do have a STM quick change aluminum sprocket and the chain was loose.

Could I have spun a bearing in the hub? Whats a new hub going to cost?
 

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greylola said:
Riding my 2000 F4 (22k miles on her) home the other day and felt something odd. I stopped to check it out and found small metal particals (aluminum) on the rear rim. My first thought was that one of the rubber cush bolts backed out and rubbed the hub (happened on my 748) but they checked out OK.

I checked and replaced the rear break pads (they needed it any way) Went for another short ride and more glitter on the wheel.

I do have a STM quick change aluminum sprocket and the chain was loose.

Could I have spun a bearing in the hub? Whats a new hub going to cost?
If the bearing is shot, the wheel is quite loose. And the sprocket can touch the hub as well. Same like when rubber cush bolts are worn out.
A hub costs about €500 but replacing bearings only can be less than €100
 

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Discussion Starter #3
I just checked the rear wheel by suspending the rear end an inch off the ground, removed the STM sprocket and break pads so that the wheel could spin freely with no noise from any other parts.

It spun smooth and quiet, and it seemed tight w/ no play, but I think I'll stay out of the triple diget speeds until I get it checked out by a pro. I hope that the metal bits are from the new sinterd break pads bedding in.
 

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Discussion Starter #5
I took a short ride and checked the temp of the swing arm around the hub... too hot too touch. So I ordered a magnizium replacement hub for $440 (half of what the stock aluminum part cost, go figure) from Ferracci. I wonder how the front wheel bearings are?
 

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That's weard. Mine has done something similar, but did not touch down in the same place and I don't have any were near the suggested miles for this type of thing to happen, which is low number in itself.
Now that I see your photo's I'm not sure what caused my problem. In my case it's the brake components that have touched on to each other. In other words the rear of the disk has begun to touch the brake caliber mounting bracket.
Anyone have any ideas on the explanation for this???
 

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something similar was done on my bike. but one mine it shaved the excentric hub and spacer itself. so the bike needed new ones, thank god it was covered under warranty.
 

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Yeah that's what I'm curious about. Mine doesn't seem to have touched these parts. Is it possible I have another problem not related to the hub bearing?

Anyone have more pictures of this type of thing on their bike(s)??
 

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Mines done it aswell..... Bearing collapsed in the hub, taking the hub with it. I also got the Magnesium part as it was half the price of the Aluminium..... How do they work that one out???????

Thats on a 2002 bike with 8k miles on it. It was also straight after riding 150miles in a rain storm, which followed me all the way. It was suggested that maybe the grease had got power washed out by the heavy rainfall...
 

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Paul Kelly said:
That's weard. Mine has done something similar, but did not touch down in the same place and I don't have any were near the suggested miles for this type of thing to happen, which is low number in itself.
Now that I see your photo's I'm not sure what caused my problem. In my case it's the brake components that have touched on to each other. In other words the rear of the disk has begun to touch the brake caliber mounting bracket.
Anyone have any ideas on the explanation for this???
Do you have any images of problem? I think it'll depend on what exactly is touching what and where.

I was pondering your problem this morning and have come up with a couple of possibles....

It sounds like the bearing race within the right hand side of the hub has collapsed and is allowing axial play and as a result the whole axle has shifted further into the hub that designed. I would think tho that the amount of movement required for this to happen would mean there would be visible clearance on the sprocket side, either between the rear sprocket retaining nut and the sprocket carrier itself or between the sprocket and hub. Although, I suppose if the sprocket carrier has seperated slightly from the sprocket then it may not be too easy to spot. I also think that if the axle has moved enough for the rear of the disc to touch down on the caliper carrier then the outer edge of the front of the disc will also be very close if not touching the caliper.

To check for axial play you will probably have to drop the rear caliper as the caliper carrier is secured to the hub, the caliper itself clamps the disc which is secured to the axel so the clearance between pad and disc my not be enough to accurately gauge true axial play in the bearing. Also, if you do drop the caliper check the piston position on each side, they should be sticking out of the caliper a roughly equal distance on each side, if not, it's a good indication that the axel has moved.

Another possible but probably less likely is that the pistons on the inner side (side which sits closest to the sprocket) of the caliper have seized solid and when applying rear brake the two outer piston are applying enough force to flex the caliper carrier and bring it towards the rear of the disc.

One more.... Perhaps the circlip securing the caliper carrier to the hub has come loose and the pistons on the outer side of the caliper are more efficient than those on the innner so every time you apply rear brake you are drawing the caliper carrier closer towards the rear disc.

You could also check that the castellations of the hub are tight against the swingarm and that the hub itself hasn't physically shifted within the swingarm.
 

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Paul,
I would guess the bearing has collapsed if the disc is rubbing on the caliper but it should be very obvious if that is the case. When it happened to my 750 it was possible to rock the bike side to side about 6" when on the MV stand and loads of glitter from hub to sprocket contact.
The only forewarning was an ignored clicking when wheeling backwards out of shed ,I assumed chain, about 2 miles later felt weird changing down for a roundabout and even stranger changing up .I stopped expecting to find a flat rear tyre .
Unless you find another reason then I would be stripping the hub to check before some real damage occurs.

Some pics of chewed mag hub due to worn out cush drives and a marked std one from a Talon quick change supplied with too long mounting bolts.

As HB suggests new bearing is a lot cheaper than new hub.
 

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Thanks for the feedback gentlemen. You were both pretty much right on target, along with the others that assumed it was the hub bearings. My problem while it had manifest itself slightly different than discribed both some of the others is basiclly still the result of a bad/damaged hub bearing - at least as far as I can tell so far.
I finally had the heart t remove the wheel and take a quick look last night and while the hub itself looks salvagable (no visiable damage) it still has the formentioned wobble / play when on the stand.
I took some good pics, but was unable to post them last night do to the size of the files. I'll try again tonight, but I wanted to ask you guy's what you did in your cases.
1. Were you able to change out the bearings by themselves or did you have to do the whole hub?
2 If you did just the bearings were did you source them? How much?
3. How the hell do you check and or lube these things once there in?
 

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I changed bearings out myself , sourced from local bearing shop. It was about 5 yrs ago and think it was around £30.00 for both . The needle roller on drive side was perfect but as I was in there just did it.

When my bearings failed there were a whole rash of bikes with collapsing bearings mine happened around 6k and fronts around 8k. It was obvious water damage but the official getout was overtorque for the rear and pressure washing for the front. I thought a shite bunch of bearings the most likely reason for the failures. I dont hold with the overtorque .
I think once you are aware of the signs/symptoms it becomes a subconcious check every time you move the bike.
 

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Paul Kelly said:
Anyone know how I can srink these picture files down to size?
I sometimes e-mail them to myself, it should ask you to 'make pictures smaller?'

This hub thing is odd, the design is back to front from Ducati 916 type bikes, where we have the needle roller on the chain side and the multipoint on the wheel side Ducati's are the other way around.
I don't think Ducati's suffer like MV do? maybe Hartley Hare knows if they do?
Ducati's also use two ball type bearings whereas MV opted to use one angular contact bearing ( still has two rows of balls though) although they are very small.

I changed my 1000S bearings before they went, the grease smelt awful and the angular contact bearing did not feel good, you do know that in the maintanance schedule it says to strip and clean the rear hub? not sure of the interval though, maybe 12000miles
 

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mikef4uk said:
I don't think Ducati's suffer like MV do? maybe Hartley Hare knows if they do?
Well, I certainly wouldn't say that the Ducati hub never suffers from bearing failure but on the surface it would appear that bearing failure on a Ducati hub is far less of an issue when compared with the MV hub.

I not sure I want to go into the intricate complexities of the whole scenario but I do know from experience that the standard MV hub is capable of operating in heavy rain conditions for 200+ miles and at greater temperatures than that achievable under normal operating conditions all without showing any signs of imminent bearing failure.

mikef4uk said:
you do know that in the maintanance schedule it says to strip and clean the rear hub? not sure of the interval though, maybe 12000miles
It's every 12000Km (essentially every second service) and replace at every 36000Km (essentially every sixth service).

I can have these failed bearings analysed which *may* help to give a more detailed explanation for the failure. If anyone is interested then send both bearings and the inner ring to me as they came out the hub (i.e. still covered in grease) and I'll have them analysed.
 
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