Author Topic: Swinging arm  (Read 7751 times)

Offline Tone

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Swinging arm
« on: 09.06. 2009 18:30 »
Hi All, Is it possible to do the pivot pin and bush on an A10 swinging arm, only the haynes manual says you need all sorts of special equipment is this right?

Online RichardL

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Re: Swinging arm
« Reply #1 on: 09.06. 2009 19:05 »
Tone,

Before undertaking this, you should decide if you have a good reason to change the "Silent Block" bushes (as they are called), as they are not easily subject to failure. I'll leave it to others here to say if they have had to replace any just for service. As for myself, I was changing from solid spindle to hollow spindle and was forced into the job. I can tell you that I thought it was the Job From Hell. First, I used a Sawzall to split the steel sleeves, as close as I could get to the swingarm I.D. without cutting that. Then, since things still weren't moving, I torched out the rubber. (Not a "green" endeavor. Remember, I am not the one suggesting you do this under cover of darkness.) Then, I was finally able to prise out inner and outer steel sleeves. Then, the new bushes were a bit too large to fit the I.D. of the swingarm, so I ran my cyclinder hone in there for about an hour. Then they seemed about to fit, so I contrived a press made from 3/4" diameter all-thread and some really big nuts. Using about a 22"-long breaker bar, I proceded on one of the sweatyist, most tedious nut turning processes I never wish to repeat. Yes, the bushes got a little deformed on the ends from so much pressure, but not so much that they couldn't be cleaned up. Then, I discovered that the inner sleeves of the two bushes were a bit out of alignment and the spindle would not pass through. Then, I bought an adjustable reamer on eBay to run down through the two spindles to get them to line up well enough to get the spindle through.

So, in answer to your question, "Sure, they can be replaced with no problem!" Seriously though, other folks reading this will, no doubt identify where I went wrong so you don't have to.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online bsa-bill

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Re: Swinging arm
« Reply #2 on: 09.06. 2009 19:57 »
There are bushes out there that are a tad too big, I had to give up on them as they were going to distort to much.
Ordered some from C& D and they went straight in without problem ( this was about ten years ago )

All the best - Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline A10Boy

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Re: Swinging arm
« Reply #3 on: 09.06. 2009 20:11 »
You might just make sure the SA spindle is tight enough, if its loose, it can move around.
Regards

Andy

1958 Super Rocket
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Online RichardL

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Re: Swinging arm
« Reply #4 on: 09.06. 2009 20:23 »
Yep! "Tad too big" describes it. Wish I had known at the time. As for spindle fit, it seemed OK when I was done.

Richard L.

P.s. No intention here of swiping the thread from Tone.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline Tone

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Re: Swinging arm
« Reply #5 on: 09.06. 2009 20:37 »
Would the bushes be worn as well as the pin , or could you just change the pin?

Online BSA_54A10

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Re: Swinging arm
« Reply #6 on: 10.06. 2009 11:23 »
If the pin is worn the the bush is worn as the pin is not supposed to move on the bush, that is what the rubber is there for.
My rule of thumb is if I can remove the shock absorbers and the bike dose not fall down the the rubber has hardened and needs to be replaced.
IF it dose fall down then you can ream the bush and fit a "speedy sleeve" on the shaft as the rubbers is still OK.
Yes it is neither clean nor fun.
Like any bush/ bearing things will be a lot easier if you cook the hole and freeze the bush.
thirty minutes in a hot oven will work wonders as will chilling the bush ( on its shaft or insertion device ) .
Do one side let it warm up remove the shaft then repeat for the other side.
If you can get your hands on it chilling the bush in dry ice is a lot better than just sticking it in the freezer over night.
Do not use liquid nitrogen as that is cold enough to make the rubber quite brittle.
Bike Beesa
Trevor

Offline MikeN

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Re: Swinging arm
« Reply #7 on: 10.06. 2009 11:35 »
Tone,
  Manosound is right ,Its a horrible job.I did mine slightly differently I used a big hydraulic press and some suitably turned up mandrels .It took several hours (and tons) and it fought me all the way.
  I did mine because i wanted the frame and s/a powder coated and was advised the rubber would not like the high temp involved.
  Then my neighbour immediately asked me to do his, which pleased me no end!
  I wont be doing another one .
  re. your last message,the pin and bushes should not actually wear if everything is set up corerectly because there are no  bearing surfaces involved.Just a twisting of the rubber.
  But the rubber will deteriate with age and oil contamination.
  Has any other m/cycle company used this method before or since I wonder?
Mike

Online RichardL

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Re: Swinging arm
« Reply #8 on: 10.06. 2009 11:54 »
Gents,

Swingarm and bushes rotate around spindle, else, no swing in your arm.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline MikeN

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Re: Swinging arm
« Reply #9 on: 10.06. 2009 12:26 »
Sorry Richard but I dont think thats correct,
  The bushes should not rotate around the spindle.
  The spindle is there to clamp the inner tubes of the bushes hard to the side plates on the frame and to each other so they dont rotate  (as well as stopping the back end falling off) .
 The outer part of the bush rotates with the s/arm .
  The swing in your arm is obtained by the twisting of the rubber in between.
Mike

Offline Brummie1960

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Re: Swinging arm
« Reply #10 on: 10.06. 2009 14:20 »
Hi,

That's something new I've learned, I also assumed the arm spindle pivoted around the bush.
In the parts book it just shows a plain cylindrical bush, no sign of any rubber.

I have just degreased my swinging arm and found the remains of some rubber around the ends of the bushes, but it was breaking up. I plan to have the swinging arm powder coated, so is it best to remove the old bushes beforehand, or leave them in place then remove/replace after power coating?

Nigel.

Offline MikeN

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Re: Swinging arm
« Reply #11 on: 10.06. 2009 14:55 »
Nigel,
  The powder coater I use is "Vulcan Enamellers" in Rustington on the south coast.This is not much use to you I realise.
  Anyway,he informed me that he coats at a temp of 200-250deg C and reckons that it would not do rubber parts any good.So I advise you to remove them.
  tell your powder coater and he will put his bungs in the bores .
  The potential problem with p/ coating is that if it gets damaged and moisture gets underneath then corosion will start and it spreads ,lifting and bubbling the coating off as it goes. My cheap swing-seat in my garden is a good example of this.
 However, Vulcan always shotblast parts, Then they phosphate dip them which is a rust resisting process,then I always pay a bit extra and he zinc powder coats them before gloss powder top-coating.
  The zinc is supposed to be the ultimate rust proofing (he tells me) and it also helps to give a deeper luster to the top coat.it also fills slight pitting (You cant use filler with p/coating).
  So check with your man to see if he does any or all of the above.
  Ive had  8 bikes done now by Vulcan and have always been pleased with the results.
 Mike

Online RichardL

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Re: Swinging arm
« Reply #12 on: 10.06. 2009 16:17 »
Mike,

Without blatantly disagreeing and exposing myself as a silly fool, I am having a very hard time envisioning how the quite thin layer of rubber can be twisted to the angular extent available for swingarm movement. Also, I am having an equally hard time envisoning getting the spindle to be tight enough in the inner sleeve to force the movement only in the rubber while also allowing for the spindle to be inserted and extracted, when need be. Bear in mind that heating the swingarm with the bushes in place, such that expansion allows spindle insertion or extraction, would have been just as impractical in 1955 (my  model year) as it is now.

Adding this point a bit after posting, I believe the rubber might just be there to avoid feeling every pebble in the road via the swingarm.

So, do we need a vote, or am I out by summary judgement?

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online bsa-bill

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Re: Swinging arm
« Reply #13 on: 10.06. 2009 16:46 »
Richard my project had the spindle seized solid in the bush, had to cut the spindle with a very thin cutting disc in between the sw/a and the side plate, the bushes were also seized into the sw/a, but the sw/a did move up and down, seems impossible but it did.
Removal was a case of drilling the rubber bushes out from both sides then forcing the inner tube out with a length of threaded rod big washers, sockets and well oiled nuts.
The outer bushes were cut with an air tool pad saw thingy then collapsed into themselves using small chisels, does'nt really matter if you cut through the outer sleeve into the sw/arm a little bit, once you get them collapsed a bit they will knock out from the opposite side of each sleeve.

The laws of physics may not always apply to A10's ( Jim)

All the best - Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online RichardL

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Re: Swinging arm
« Reply #14 on: 10.06. 2009 19:29 »
Bill,

That sounds more like rust and corrosion than intension on the part of BSA. I doubt that their service manual read, "To service the swingarm spindle and bushes, start by cutting off the end of the spindle with a cutting disk that will be invented some time in the future."

I am still not ready to accept the frozen-to-the-spindle answer. Perhaps the term "Silent Block" referes to sound deadening of road noise by virtue of the rubber. After all, they are not called "Bounce Blocks" or "Swing Dampers" or the like.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.