Hi. Today I fitted the bearings into the rear hub of my 1960 Dommie 99 project. The right-hand one (single row bearing) is fully butted up against the step inside the hub - that’s good. However, the the flange on the bearing retaining ring/speedo drive ring doesn’t screw down fully against the hub. The ring is fully tightened (thanks to the AN peg spanner - great bit of kit) but the flange on the lock ring doesn’t touch the hub - there’s a gap of about 1mm. It’s exactly the same with the old (original, but damaged) locking ring so I can only assume that the sealed bearing is a bit thicker than the old open-faced bearing. The questions I have are:
1. Is that 1mm gap going to cause problems?
2. Should I try and fill that gap with a thick washer?
3. As the ring is only biting against the bearing outer race and not against the hub, is there a chance of it coming loose over a period of time?
4. As the locking ring is sitting 1mm further out than it should, will that cause problems getting the hub to fit
in the swing arm?
Thanks very much.
Regards
Tony
I don't think its a problem…
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Hi Robert. Thanks for the…
Hi Robert. Thanks for the reply. I must admit that I was tempted to just see how it all fits into the swing arm before considering whether or not to attempt to engineer the exact thickness of washer required. The danger as I see it is that if the washer is too thin it will rattle and not bridge the gap, and if it’s too thick, it will prevent the locking ring from clamping against the bearing. Not an easy fix!
Regards
Tony
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We are thinking on different…
We are thinking on different lines, my fault,rambling on ! , I don't think even when new the ideal of the ring being tight to both surfaces was expected. Not realistic ,more important that the ring bear down on the bearing and hold it tight . Worry not,be happy !.
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Agree..
.. with Robert, its job is to locate the outer bearing race. It doesn't matter if there's a bit of clearance on the flange.
It's similar to the central spacer tube which is slightly longer than you might expect so that the inner races are all held by the spindle with no chance of an endways load on the bearing as the outer on the brake end isn't positively located so can find its own position. One reason why when you first fit a back wheel it can be a bit tight to turn until the bearings settle down.
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Robert/Ian. Thanks for…
Robert/Ian. Thanks for putting me straight on the fitment of the locking ring. There’s so much wrong with my bike that I just assumed this was yet another problem.
Regards
Tony
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Keep a wary eye, You will…
Keep a wary eye, You will find problems ---if you are looking !.
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Agree....my advice is to…
Agree....my advice is to make absolutely sure that you are completely happy with the assembly. Whilst, from what you've posted, there doesn't seem to be an issue (and I agree the Domi swinging arm does have some 'spring' and you could in theory adjust the right-hand spacer) but if you're not comfortable, then strip it all back, measure everything and convince yourself that it's good to go.
The other thing I'd mention is that, generally speaking, excessive side-loads from poor assembly will kill a wheel bearing faster than the radial loads it sees when in action - that goes for ball races and taper rollers.
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I don't think its a problem. Its unlikely the dimensions would ensure that the ring fits tight to both.Has to be one or tother!. The swinging arm has a bit of spring in it too. I have a similar issue on the Atlas where to fill a gap that should not be there we have added an additional thick washer. This has the unfortunate result in putting an uneven pressure on the speedo drive and buckling it!. Now I have to take some very carefull measurements to ensure it all tightens up square. So you can see why I'm interested in your issue.