Swinging arm play

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Pharisee
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Swinging arm play

Post by Pharisee »

I was giving the M18 a "once over" in preparation for a 180 mile trip south to see my brother in Kent and detected what I first thought was a little play in the rear wheel bearing. It turns out that it is, in fact, a little play in the swinging arm bushes. It's not a lot... but it is detectable. How much play would you consider permissible (or acceptable) before taking the bike apart to replace the bushes and/or the pivot pin?
John
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Rob Harknett
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Re: Swinging arm play

Post by Rob Harknett »

Place a piece of wood over the round cap, the wood at the other end against a wall. The weight of the bike leaning on the wall via the piece of wood.
Place another piece of wood on the round cap facing you. Give the wood a wack with a club hammer. Job done, side play gone. Have a good trip.
Mick D
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Re: Swinging arm play

Post by Mick D »

Hi

Play in this type of bearing is inevitable after a period of use. Don't worry about it unless it becomes noticeable when entering corners. Fix it when next convenient. Before I restored mine there was around 0.010" axial play, nil radial. I don't recall ever noticing it when cornering, (though it was over 40 years ago).

Beating the end caps would have no effect on my 61 swinging arm, the bushes are not in contact with them, and if you're going to take off the primary cases and drive to get a lump of wood onto the LH cap you might as well pop the arm out and do the job properly ;)
SA Bush.png
Regards Mick

Edited to add: Well every day's a school day - bit of reading reveals there is a sleeve between the bush and SA so whacking the cap could move the sleeve and thus the bush. :oops:
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Rob Harknett
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Re: Swinging arm play

Post by Rob Harknett »

The bike is 1955. Nothing to remove. When I questioned a bit of side play decades ago, old boy that worked on the bikes showed me what to do. The spoke also needed tightening a bit. The bike had felt seals, they do wear and compress. Also bushes are known to creep out and cause side play.
See this article https://www.jampot.com/article_read.asp?id=227 When you get down to the last but one paragraph, ask yourself. Do I really need to do all that work replacing parts that do not need replacing. As side play is caused by creeping bushes. At least try the above mentioned, to cure the problem, or rule out side play is not caused by creeping bushes.
Last edited by Rob Harknett on Sun Jul 18, 2021 9:10 am, edited 1 time in total.
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Pharisee
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Re: Swinging arm play

Post by Pharisee »

Thank you, gentlemen. I would never have considered doing that. It will have to wait until I get back from Kent, but I'll give it a go!!
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Rob Harknett
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Re: Swinging arm play

Post by Rob Harknett »

Have a good trip. Please let us know if it was creeping bushes causing the little side play. All you had to do was as I mentioned ( A wack and tighten the spoke )
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Pharisee
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Re: Swinging arm play

Post by Pharisee »

Rob Harknett wrote: Sun Jul 18, 2021 9:14 am Have a good trip. Please let us know if it was creeping bushes causing the little side play. All you had to do was as I mentioned ( A wack and tighten the spoke )
Just been out to put the soft panniers on and have a look at the swinging arm. I can get to the right hand side if I move the oil pipes but I'd have to strip off the primary drive on the left side.
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20210718_104737.jpg
20210718_110648.jpg
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Rob Harknett
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Re: Swinging arm play

Post by Rob Harknett »

Pharisee wrote: Sun Jul 18, 2021 11:10 am
Rob Harknett wrote: Sun Jul 18, 2021 9:14 am Have a good trip. Please let us know if it was creeping bushes causing the little side play. All you had to do was as I mentioned ( A wack and tighten the spoke )
Just been out to put the soft panniers on and have a look at the swinging arm. I can get to the right hand side if I move the oil pipes but I'd have to strip off the primary drive on the left side.

20210718_104714.jpg

20210718_104737.jpg

20210718_110648.jpg
It is tight getting on the caps, I have managed to do it quite easy without removing anything.
Getting the bike leaning on the piece of wood to prop the bike against the wall is the tricky bit. You may need a hand from some one holding it in place, while you get on the left side. The handle bars also against the wall helping to keep the bike steady.
By the way, you have your rear brake rod on back to front. The adjuster end should be on the lever arm at the back.
It gives better access to the primary drive chain case fittings and the brake adjuster at the back where it should be.
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