M900 loose rear wheel bearing

[FrankenDesmo]

Long time no post... (Over a year apparently!)
Criminally, my bike has sat in the shed all year as I've been spending all my time and money on my other toy, the Mazda RX-8. Also I discovered a perished fuel hose early in the year so drained the tank, order some hose, and haven't got around to fixing it...

But I digress.

I'm looking to start giving the bike a strip down and refresh, something I'd always intended to do fairly early on, but got sidetracked by the car.

One thing I have noticed is that the right side wheel bearing on the right wheel literally falls out of its seat, and that can't be right, right!?

So, is this repairable or do I need to replace the wheel? I am assuming the latter given the hole the bearing sits in must have been spun out, unless the bearing is suppose to be fixed in place with some super strength loctite or something, rather than just a regular press fit.

[Dukedesmo]

Shouldn't do that and given the bearing is harder than the wheel it sounds like the wheel maybe worn away but, it's worth trying a new bearing as you never know the bearing maybe slightly undersize?

Otherwise, bearing retainer may work, depending on how loose it is - no good sticking it in place if it's not dead central!

[FrankenDesmo]

Thanks, that's what I thought, trying a new bearing is a good shout, and searching around it seems that loctite 638 could be the solution - as long is it's not too flogged out as you say.

I'm guessing this isn't a common fault either so I'll look into a replacement wheel too, as that's prob the ideal fix.

[900Rebuilder]

Had this on an MTX125 many moons ago and I fixed it with the aid of some Loctite stud n bearing fit. I assume like you mentioned that my bearing seized and instead of locking the wheel simply span the bearing in the hub.

[FrankenDesmo]

I've got a new set of bearings on the way so I'll see what their fit is like. The ones on it came with the bike and haven't seized, it's just that one in particular tends to fall out quite easily when taking the wheel off the bike. I'll try to salvage it if I can as it's an elephant marked original 93 wheel. Searching I've seen others recommend bearing retainer and also I've seen shim tape mentioned - or having the wheel machined and an insert fitted, though that would start getting expensive I'd imagine.

[Dukedesmo]

I would think, if it's not loose (in as much as it rattles about in the hole) then bearing retainer should be OK?

As it runs it will warm up anyway and expand slightly for (maybe) a better fit? The wheel shouldn't be heating up as much if the bearing is working so should stay put.

But if it's too loose (how loose is to loose?) then, either a new wheel or yours repaired with the insert is the way to go.

[FrankenDesmo]

It's been a while since I've actually had the wheel off, I got to thinking about it as I'm looking to start the wee refresh project this winter and the local wheel refurbishers usually run a good discount leading into Xmas (I've had 2 sets of car wheels done the last two years on this deal), so figured I'd sort the bearing situation first.

It definitely wasn't rattling around in there from memory, just easily removed.id imagine too loose is beyond the gap spec of the retaining fluid, which is different for each of the various loctite versions. I think retainer alone is probably going to be enough, though the shim tape idea is interesting as it is think stainless steel adhered to the bearing, and being a wheel bearing is not under a lot of heat or rotational stress (unless seized, which won't be happening if I can help it - they're cheap enough to replace annually if I wanted to). But that assumes the gap is big enough to accommodate tape, which even at the thinnest available is probably too thick and just wouldn't fit once applied.

[Dukedesmo]

If it were mine, I could live with retainer if it was a good enough fit.

I've got no idea how thick shim tape is but, if you can get it in the gap, then the gap is way too big IMO and, at that point I'd be looking to repair or replace the wheel.

[FrankenDesmo]

Aye exactly. Anyway, all speculation until I get a chance to see if the new bearings fit snugly, and if not, how loose they are to determine what to do next, but I'm expecting that retaining fluid will be plenty enough to solve the problem

[adie851]

I've come across the same problem on a mates 600 monster back wheel (RHS) bearing.A new bearing was still too slack. I think you could say the bearing housing in the wheel casting has gone slightly oval. Apparently some decent bearing suppliers do a kit ...think it consists of a sleeve/collar to fit into the wheel then you need to machine it out to fit the new bearing nice and snug. I'll let you know how it progresses.

[FrankenDesmo]

Do you have any links to suppliers that do these kits?

[Mr Gazza]

I wouldn't have thought that buying a kit with a pre-made insert would be worth it?
By the time you have found someone with a lathe big enough to swing a whole wheel and also make the necessary jigs to hold it perfectly central, I'm sure they would be more than capable of making the insert.
I think it would also be better to machine the inner diameter, (the one that the bearing must fit into) after the insert was seized in with a good interference fit. It's all too easy to distort the insert when fitting and far more engineering sense to machine it perfectly concentric and round after it's fitted.

The first step is measure carefully exactly how much gap you need to overcome and any ovality. I'm sure you'll find that it's well within the scope of what the bearing fit jollop will do.
Wheel bearings should do tens of thousands of miles, so the next bearing change is most likely a problem for the next bloke..

[FrankenDesmo]

Oh no, this bike is a keeper! :⁠-⁠D

Btw the headlight ring is holding up well, and no big deal swapping in a LHD lamp for a trip to France last year :⁠-⁠)