Sprint ST rear wheel bearings

[Bass]

About 20,000 km ago, I started getting a clicking noise from the rear of the Sprint (single sided swing arm). It was evident when wheeling the bike but disappeared when the bike was put on the stand and and the wheel spun by hand. Initially I thought that it was something to do with the chain and sprockets as it did not appear to be synchronous with wheel rotation. Since they had done about 70,000 km, while they still looked OK, starting to wear but with some life left, I replaced the chain and sprockets anyway.
The noise remained and was finally traced to the hub.
The hub was stripped and we found 2 ball bearings and also a needle roller bearing which had a barely discernable crack in the roller cage. All other components were in good condition. An unusual aspect of the assembly is that the axle is also the needle roller inner race and so must be well hardened.
All the bearings were replaced at considerable expense and the noise disappeared but now is back and worse than before. I therefore surmise that the needle roller cage has crapped out again.

What the hell can be causing a needle roller cage to crack when all other components including the bearing surfaces appear to be A OK?

[White trash]

What the hell can be causing a needle roller cage to crack when all other components including the bearing surfaces appear to be A OK?

The bermuda triangle. That's some spooky shit right there.......

[Maha]

I hear what you are saying Neil, well, no I really dont, you know how stuff like that scares me
But anyway, I see my old Sprint on trademe and its had its rear wheel bearings replaced at about the 52,000 Km mark.
The picture used is the one I used just over two years ago to sell it...
http://www.trademe.co.nz/Trade-Me-Mo...-332790367.htm

[Bass]

That's some spooky shit right there.......

I hear what you are saying Neil, well, no I really dont, you know how stuff like that scares me

I do appreciate the input gentlemen, but I'm not getting a heap of useful information so far, eh?
Still, if it was easy Girl Guides would be doing it and I wouldn't be asking curly questions in here.

[Mom]

Are you certain that the axle is not worn somewhere? Faulty bearing installed?

[Max Preload]

Is it a caged roller bearing or a roller bearing c/w its own outer race? What about the other bearings - are they deep groove ball or pre-loaded spherical roller?

I'd be interested in seeing a cross-section of this assembly arrangement if you'd do a sketch.

[Max Preload]

No worries. Here's a pictorial view.

[Bass]

Are you certain that the axle is not worn somewhere? Faulty bearing installed?

Not yet Anne as I haven't managed to get it apart again yet. However it was fine the last time it was apart with this problem. The axle is the inner bearing race and so will be well hardened. Consequently it will fret before it wears. However, once I get it apart again (the nut on the drive side is being especially stubborn), if the axle is marked this time, well there's the answer.

No worries. Here's a pictorial view.

That's the sucker!

[Mully]

Hmm - is there a Sprint forum you can go onto to have a look to see if this is an issue.

Should the bearings be greased every so often? Maybe they're shitting themselves cos they're not greased.

Or maybe you had too many pies?

[Scouse]

Hmm - is there a Sprint forum you can go onto to have a look to see if this is an issue.

Should the bearings be greased every so often? Maybe they're shitting themselves cos they're not greased.

Or maybe you had too many pies?

Or maybe a Triumph Dealers work shop could sort it fairly quickly

[Bass]

Should the bearings be greased every so often? Maybe they're shitting themselves cos they're not greased.

Or maybe you had too many pies?

The needle roller is sealed both sides and had plenty of grease in it when it came out. The bike does do a lot of running 2 up with luggage but for the life of me, I can't see how normal loading would cause the cage to crack - it is unaffected by external loads.
I hadn't considered a Sprint forum. That's good thinking - I'll have a look.

[Bass]

Or maybe a Triumph Dealers work shop could sort it fairly quickly

Perhaps, but there is nothing adjustable - it's all circlips and shoulders. Just drop everything into place, tighten the nut and bend the locking tab into place.
Incidentally, I have it apart again now and I can't find a damn thing wrong. Bugger! However I haven't inspected the surface of the needle roller outer race as the cage has to be destroyed to get to it and I would probably damage the race in the process anyway.
I would have had it all back together again with fresh bearings yesterday and out on the road today, but Saeco Wiri closed early. Bastards. Just wait till the rep calls on me at work next time.

[Bass]

Well, new bearings, seals and it's back together. Reassembly was a breeze - took about 15 minutes.
No clicking anymore and no idea what was wrong either. So no idea when it will happen again. Bugger!