Originally Posted by kezzajohnson
I don't understand how the bearing could be off centre in the carrier however. That is really strange.
If you look where the bearing is in the hub, you can see that it isn't centred on the sprocket, and there is only one bearing, so the chain pull is trying to constantly 'twist' the bearing, which they are not really designed to do. A second bearing, like a non cush hub wheel, counteracts the load. Just me speculating, but I suspect the major issue is that stock they are unsealed. Ball bearings certainly do handle lateral loads, but IMHO it'd be better if it wasn't designed into the hub.
After I got my DR I did a fair bit of research on the net to decide what needed attention, and I have not found any reference to this as an issue. I haven't gone through all of the 'big one' aka http://www.advrider.com/forums/showthread.php?t=135295
This thread does however seem to have identified a few others.
I also acknowledge Snowy's assertion that you'll feel slop long before it fails, however in my case, I'd not long had the wheel off after lacing up the 18" rim and I always check these things, wheel bearings etc when wheel are off and when lubing chains. This is why it really surprised me, the suddenness of it, and that I'd not long checked it. It also twisted the chain, effectively destroying it. I was lucky I wasn't far from the shed, just playing with jetting, and testing. I was in 1st gear at the time. 10 mins before I was up my hill and doing 110 kph on the bitumen doing more jetting tests.
The bearings are a pretty common 6205 and the seal is a 12522, and can be obtained easily, mostly off the shelf from autoparts, ag supplies, bearing places, etc. $10 should get you a bearing and seal. The seals can be recycled though, and bearing places normally stock the double sealed bearings and allow the customer to remove any they don't want to reduce stock. I reckon leave the seals in place.
Fully repacking wheel bearings can be a mistake. When they heat up, the grease oozes out, and they can run hotter too. I tried it once years ago and wondered why I had no brakes, bearing grease on the disc was the issue.
I'll add my experiences here when I get a moment:
My Dr came delivered with worn E09s. I swapped them to the current MT21 E07 combo when I put the 18" rim on. I've never really felt confident on it until test riding the new forks last week.
I have a C02 on the back of my Berg at the moment. They are not a bad compromise around here, lasting extremely well on the rocks, but they never really hook up either. Great trail tyre, but not for racing. I like the 952 up back as it lasts nearly as well and maintains traction as it wears fairly well. Never liked the 952s up front though, vague feeling when transitioning. Always liked BS 201s and Dunlop 773s up front though, intermediate to soft seems to be the answer for the rocks here, and these 2 don't shed knobs like many others. Both superceded though, and I haven't tested the replacements yet. I've still got a few in the shed to work through yet.
My thinking is that in between the rocks we have lots of soft powdery stuff which is why they are the best compromise for me. I haven't tested on the DR yet, but I got the DR to cruise on, not to go flat out....
A ride later this week would be good Snowy, I'll pm you.