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swing arm bushes

Posted: Sun Oct 27, 2024 6:22 am
by david.anderson
For many years I have removed the Silentbloc bushes from the swing arm of the Ariel and have made up bronze bushes, end washers and a pivot pin which gets rid of that spongey rear end. Recently I looked at what bearings were available that I could use and had hoped that I could adapt some tapered rollers but with nothing suitable I looked elsewhere and spherical plain bearings looked like they might do the job so I bought some, but then my lathe developed a problem so I have gone no further. But it will be an easy job to make some spacers and a shaft to complete the job. Spherical bearings are suitable for use where there are high radial and axial loads.
Has anyone here tried spherical plain bearings in a swing arm and how have they lasted.
David

Re: swing arm bushes

Posted: Sun Oct 27, 2024 8:18 am
by paul.jameson
You could always do what Healeys did and use a combined ball and roller bearing. The ones on my first Healey were still good after 40,000 miles. Size availability is understandably limited and the method of assembly can tax the brain but they do work well.
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Re: swing arm bushes

Posted: Sun Oct 27, 2024 12:41 pm
by Vesa Helske
There seems to be a remarkably small diametre hole for the pivot pin, in the inner sleeve! Or is it to be further opened up?
Vesa

Re: swing arm bushes

Posted: Sun Oct 27, 2024 5:20 pm
by paul.jameson
The Healey swinging arm spindle is 1/2" diameter whereas the Ariel one is 9/16". But the Healey spindle has a massive sleeve between the engine plates, much bigger than the Ariel one between the bushes.
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Re: swing arm bushes

Posted: Mon Oct 28, 2024 5:57 am
by david.anderson
Thanks Paul but I cannot find any bearings that are suitable although there are 32mm bearings that may do if I was to enlarge the Ariel S/A slightly. The Healey appears to be larger. The Ariel swing arm is only 1.25” od and that really restricts the bearing type to plain bearings or one with needle rollers but needle rollers do not control axial forces so something else is required for that, which the combined roller/ball can do. The spherical plain bearings that I have are 1 ¼” od, ¾” id and 21/32’ w. That gives me a ¾” shaft with the 9/16” through stud which should work well. My concern when the bearings arrived is just how long they will last given the small contact area so I was considering fitting two per side.
However after going on line I found that one of the Harley models had Silentbloc swing arm bushes and there are spherical plain bearing kits for sale to replace the Silentblocs and they are supposed to be very long life.
So for now I will continue with the spherical bearings and time will tell if it is a success.
David

Re: swing arm bushes

Posted: Mon Oct 28, 2024 8:10 am
by paul.jameson
For the record, the bearings I used on the Healey are SKF NKIA 5906 (Made in Slovakia !!). You might just be able to use an NKIA 5903 but, as you say, the Healey is a lot bigger diameter. Good luck.
Paul