Firstly can I thank everyone who responded to my previous rear wheel query and helped ‘clear the fog’.
I attach two photographs of the S/A I intend using on my Triton. I believe it’s a wideline item and it has virtually identical overall dimensions to the slimline S/A I also have. It has,however, wheel adjuster threads that appear to be 5/16” bsf or possibly BSC. From comments I have read on this forum this sounds rather non standard. Any ideas at all ? Perhaps they’ve been drilled and tapped to a larger size?
The other query relates to the metalastik bushes. On my slimline S/A the bushes protrude from each end of the pivot such that the overall width dimension across the inner sleeves matches the internal dimension across the frame gussets. On the wideline the bushes do not protrude from the pivot area but are flush to the S/A, also it came with a pair of endcaps to make up the difference in width to the frame dimension.
So far as I can tell without removing the bushes the body of the S/A is identical in width to the the slimline version. So what on earth have I got?
I intend having the bushes replaced though possibly the internal spacer may be missing (any suggestions as to some one to do this in S Bucks gratefully received)
In case you are wondering why I don’t just use the slimline unit (Here goes I might as well get this over with now. I have despoiled a slimline frame by having the rear end ‘manxed’ by Mr Degens and what makes it worse it’s a Manxman frame). This means the rear suspension top mounting points are not as wide as on a standard slimline and line up much better with the narrower mountings on the unit under discussion. Thank you everybody for you help - I now await the first salvo from Yorkshire.
Best regards
Peter Bowman
Chain Adjusters
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Removing the metalastic…
Removing the metalastic bushes is no trivial task. The works allegedly resorted to burning them out on occasion. Are you really sure they must go?
Obviously if there is no centre spacer, the job has already been done by someone who managed to do the difficult bit but not the easy bit (putting the correct parts in.), so you'll have to do it again.
If it has a spacer between the bushes, I would just add some washers (as thick as possible) to spread the load from the inner tubes to the frame plates. The plates sometimes wear away if the swing axle bolt is not tight enough to do its job properly and totally prevent the inner tubes in the bushes from rotating.
And I think the manuals remind us that it should be tightened with a friend sitting on the saddle to compress the arm to the normal ride height.
I seem to remember there might be more than one outside diameter for the bushes. And tolerances might be suspect. Good luck!
You probably have seen this:
It should be obvious if the correct spacer is there, because the spacer internal diameter is only just enough to allow the bolt to go through (because it acts between the inner and not the outer tubes), so you should be able to feel it with a wire coathanger. Maybe the PO wrongly used a tube as a spacer between the outer tubes of the bushes? If that is so, you have no choice but to get them out again. I hope he does not make a habit of it!
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Missing spacer
When I bought my Atlas from a club member who had just 'restored' it, the rear wheel suspension seemed stiff. I removed the shock absorbers and found one had a bent damper rod. With the shock absorbers removed, the swinging arm movement seemed to grate - it should flex on the metalastic bushes. I removed the swinging arm and like you, found the metalastic bush inners were almost flush with the swinging arm outer tube and they moved inwards when pressed together.
I drilled through the rubber multiple times until the inners were freed, then carefully cut a slot through the outer shells and they there came out easily enough - a bit laborious, but not difficult. On removal, as suspected, there was no central spacer fitted. This was only one of a number of mistakes/ incompetence that i found, most of them serious.
Andy
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Metalastek bush puller
I made up this puller using 16mm studding. I reckon it took 2 - 3 tonnes to shift 'em. I put the studding through a 3/4" drive socket to actually push against the bush outer, with a slightly larger socket at the other end to accept the bush as it emerged.
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Swinging Arm queries
Thank you all very much for the information. I’ve tried both bsf and bsc bolts without success and I am beginning to think the wheel adjuster threads are in fact UNF. I had tended to think this unlikely due to the probable age of the item. Perhaps some one tapped it this size to fit the Commando adjusters. I now need to find a 5/16 unf bolt to prove the point.
So far as the metalastik bushes are concerned I think I’ll definitely farm the job out. I believe Norvil can do it thong I have no idea of costs
thanks again
Peter
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There is quite a lot of info about these items if 'Chain Adjusters' is entered into the Search Box (Top Right).
The pre-Commando Big Twins should have weedy 1/4" BSC adjusters.
The Commando used a much beefier 5/16" UNF version.
Dominator Swinging Arms that have worn adjuster holes can be easily tapped oversize to 5/16" and a set of 5/16" BSF bolts with reduced heads will do the job.
As an alternate for the above, the chain adjusters for the earlier rigid singles used a ready to fit 5/16" BSC set-up. That's if you can find them.
Replacement Numbers as follows.........
Dominator - 067736 (19264)
Commando - 060650
Some Early Rigid Singles - A2/483