Wheel adjuster threads in swing arm

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Hi.

Today I discovered that the chain adjuster threads in the end of the swing arm have been stripped (apart from the last 1/4 inch at the bottom of the hole). That means that the adjusters are really just a sliding fit in the swing arm when the chain is fitted. As the chain adjusters have a separate nut for locking the adjuster in place, could I use that to set the position of the wheel adjuster and therefore the position of the spindle? I’m assuming that as the spindle nuts lock the spindle in place, the fact that the adjusters simply rest against the adjuster locknuts will be ok as they are simply being used to set the position of the spindle before locking it in place with the spindle nuts. I’m hoping that I don’t have to buy another swing arm.

Any views and advice gratefully accepted.

Thanks

Regards

Tony

shouldn't be a problem, the…

shouldn't be a problem, the chain adjusters are really just locaters, as long as the spindle is tight all should be o.k.

you could always tap out the holes to take a slightly bigger bolt.

Our atlas has bigger…

Our atlas has bigger adjusters than the 99 , perhaps you could fit those?.

Hi Robert - The master Parts…

Hi Robert - The master Parts list for the 1966 to 1968 Models shows part number 19264 for the Rear-wheel adjusters and E.3229 for the corresponding nuts. It does not specify the size nor thread form, sadly. However I can confirm that my Mercury (1969) has the same adjusters as my early Dommie with the exception that the adjusters and nuts are cadmium plated and not satin chrome. The thread form and size is most certainly 1/4 inch BSCycle. So either your Atlas has been modified or the Mercury took a regression in this area. There is another possibility - My Mercury may have had an earlier swinging arm fitted when it was in the Eastern Caribbean...Ho hum........ I suppose this is an almost pointless contribution? Cheers, Howard

Thanks guys. That’s the…

Thanks guys. That’s the reply I was hoping for.

Robert, do you by any chance know what diameter and thread the Atlas adjusters are? If they are substantially larger diameter, there might be enough ‘meat’ in the swing arm to re-tap the holes to the larger size.

Thanks again

Regards

Tony

Hi Tony, The same type of…

Hi Tony, The same type of swinging arm is fitted to both bikes but the Atlas is 7 years younger and built by AMC Norton who made lots of changes .Seems likely that should be a straightforward job. You may need a longer tap and drill than usual or an extension bar to get past the fork ends. Will look up info later. Pre Mk3 Commando look a possibility . Thread will be 5/16th UNF (probably!) in place of the 1/4 cycle 26tpi