M900 Rear Wheel bearing?

[Porsche Monkey]

Hey guys.  I was lubing my chain this morning with the bike up on my rear stand.  The wheel had a tight spot in it when I was turning it to lube the chain.  I started looking around and found that the brake rotor bracket was rubbing on the rim right at the center next to the wheel bearing.  I pulled the wheel off to inspect the bearings thinking that one of them may have failed but they turn freely.  The wheel bearing on the rotor side is loose in the wheel though and will just come out without any force.  Looks like it may have spun, but there is no scoring, just some pitting.  All the parts seem to be in there.  Has anyone seen this before?  Looks like I may be in the market for a new rear wheel. 

[Ddan]

Got any pics?  is the big cone-shaped spacer in correctly?

[Porsche Monkey]

No unfortunatly I didnt take any pics.  I believe the tapered washer is in correctly because it appears to only go in one way, with the taper facing the bearing.  That bearing appears fine, its the other one one the brake side.  It doesnt fit in the wheel tightly at all.  I can wiggle it back and forth once its installed. 

[Howie]

OK, the spacer is in the right direction.  Before running out and buying a new wheel I would try a new bearing and see how it fits.  I think, with your car experience, you will know.

[Porsche Monkey]

Ill try the cheap way out first.  The thing is the bearing feels and looks fine when you spin it by hand.  Just fits loose in the wheel.  Ill see if I can source a new one locally. 

[bigiain]

Hey guys.  I was lubing my chain this morning with the bike up on my rear stand.  The wheel had a tight spot in it when I was turning it to lube the chain.  I started looking around and found that the brake rotor bracket was rubbing on the rim right at the center next to the wheel bearing.  I pulled the wheel off to inspect the bearings thinking that one of them may have failed but they turn freely.  The wheel bearing on the rotor side is loose in the wheel though and will just come out without any force.  Looks like it may have spun, but there is no scoring, just some pitting.  All the parts seem to be in there.  Has anyone seen this before?  Looks like I may be in the market for a new rear wheel. 

Yeah, I had it happen to me - I'm told what happens is if you hit a big bump, the bearing races are hard enough to deform the wheel, and once that goes far enough it starts beating itself further every time it goes round... I bodged mine for a year or so by JBWelding the bearing in place, but eventually go the wheel sent off to a guy who machined out the bearing seats and pressed in some inserts he made up to suit. It cost me ~$100 from memory (I don't remember the exact amount, but I do remember it was about half what a 2nd hand wheel from a wreckers would have cost). That was ~90,000km  (~55k miles) ago now and it's holding up great...

big

[Porsche Monkey]

Yeah thats probably whats going on cause it doesnt look like the bearing has actually spun in the wheel.  Machine shop time. 

[Porsche Monkey]

So is the bearing supposed to be flush with the wheel or recessed a little bit?

[RobotDan]

Hey, my rear wheel bearing is bad, do you guys by any chance have a part number/size for a  '94 m900. I looked in my chiltons, on here, as well as the old site but I found nothing. I did see some info for a '00 750 but I thought it might be different.
cheers,
Dan

[supertjeduc]

I think it will be 47mm outside 17mm inside and 14mm wide i have a old koyo which has 6303RS on it

[RobotDan]

awesome, thanks man

[bigiain]

eventually got the wheel sent off to a guy who machined out the bearing seats and pressed in some inserts he made up to suit.

I had it apart changing the chain and sprockets last weekend, and took a snap of it...



(click the image to see it larger)

big

[Desmo Demon]

Yeah, I had it happen to me - I'm told what happens is if you hit a big bump, the bearing races are hard enough to deform the wheel, and once that goes far enough it starts beating itself further every time it goes round... I bodged mine for a year or so by JBWelding the bearing in place, but eventually go the wheel sent off to a guy who machined out the bearing seats and pressed in some inserts he made up to suit.

The same thing happened to the rear wheel on my ST2. There were no signs of the bearing spinning in the hub and the bearing's OD was not changed, so replacing with a new bearing should have produced the same results, so.......I used blue locktite to hold it in place. It's been fine for about 10k miles, so far. It shouldn't be difficult to remove when I have to since I used the locktite.