The BSA A7-A10 Forum

Technical => Frame => Topic started by: Truckedup on 23.08. 2020 23:32

Title: Hate the swingarm
Post by: Truckedup on 23.08. 2020 23:32
 Hate it because it resists removal. The damn frame is just a touch too big to fit in my shop hydraulic press..I really can't see a way to use the oxy torch on it..Used a 4 lb?? hammer on an aluminum  block trying to drive it out...Used the Porta Power ram to force the frame gussets apart slightly....Drilled a small hole to spray in penetrating oil....New spindles are available for $50 , I don't want to make a mess cutting it......
  So...just cut it?
Title: Re: Hate the swingarm
Post by: chaterlea25 on 23.08. 2020 23:52
Hi
Quote
  So...just cut it?

Yup  *work*

John
Title: Re: Hate the swingarm
Post by: KiwiGF on 24.08. 2020 00:35
Hate it because it resists removal. The damn frame is just a touch too big to fit in my shop hydraulic press..I really can't see a way to use the oxy torch on it..Used a 4 lb?? hammer on an aluminum  block trying to drive it out...Used the Porta Power ram to force the frame gussets apart slightly....Drilled a small hole to spray in penetrating oil....New spindles are available for $50 , I don't want to make a mess cutting it......
  So...just cut it?

I distorted the frame gussets trying to force it out, its much safer to use a thin cutoff wheel, and then buy a new spindle.

Unfortunately its still a rotten job getting silent blocs out of the swing arm. There are plenty of threads on this, including from me.

Getting New silent blocs that last seems to be an issue at the moment, according to some recent threads.
Title: Re: Hate the swingarm
Post by: Joolstacho on 24.08. 2020 01:10
Best left well alone!
Title: Re: Hate the swingarm
Post by: Peter in Aus on 24.08. 2020 02:13
As KiwiGF says the only way (not the only way, but the easiest) is to use a thin blade cut off wheel and 4" angle grinder, blade will just fit between the frame and swinging arm with out damaging any thing, be carful when doing it as the blade can jam and fly to bits, so use all the safety gear.
Peter
Title: Re: Hate the swingarm
Post by: Jules on 24.08. 2020 03:44
"if it aint broke, dont fix it", applies well to the swinging arm, IMO.....
Title: Re: Hate the swingarm
Post by: Swarfcut on 24.08. 2020 08:28
  Trucky    I made a simple observation on the crude design of the swing arm a few weeks ago and felt severely reprimanded for offering a different opinion.
  When newly assembled the inner tubes of the silentbloc bushes are clamped between the frame cheeks,  which is a relatively small area to provide resistance to turning.  Over time as you have found the spindle and inners seize together and whether by design or accident the inners are now well retained along the length of the spindle and resistance to rotation is now transferred more and more from the small areas on the frame cheeks to the spindle retaining flange and bolt. This seizure is why the spindle won't come out, and if the bushes still offer reasonable  resistance to turning and spring back, experience is that they can be left alone.

   Cutting through the spindle is the least violent and damaging method of removal. Then there are various tricks on the forum to remove the bushes. Worth getting new ones before you start and checking the length of the inners. Some are made a bit too long. They must meet in the middle and protrude just enough to very closely match the inner cheek distance. Too big, the arm won't fit, too small will draw the frame  innwards.

   Opinions differ on the final tightening, so I will leave you to consider the options. The two "J's " Pete and the KiWi are all on the money here with some sound advice. Thanks fellas.

 Swarfy.
Title: Re: Hate the swingarm
Post by: Truckedup on 24.08. 2020 11:04
  Ok, thanks....I have some  a stack of thin cutoff blades...Also thinking of fabricating  a metal or Delrin bushing arrangement .....Or not....
Title: Re: Hate the swingarm
Post by: edboy on 24.08. 2020 20:47
if you have a workshop convert to needle rollers.
offhand i cant remember  the sizes but worth the work as the beeza handles better as well.
for a cross over shaft inner bearing sleeves fit on the hollow shaft but you have to make an inner spacer to keep everything in place
i convert all mine. face a grease nipple downwards for easy maintenance.
Title: Re: Hate the swingarm
Post by: Truckedup on 24.08. 2020 21:41
 I cut the spindle, no damage to frame or swingarm...The oxy acetylene torch made quick work of rubber bushings.   Now the bushing outer sleeve is stuck fast to the swingarm tube..I welded a bead around the inside of the tube so I can use a drift to knock it out from the other side....The 20 ton hydraulic press won't  move it.....Interesting.....
Title: Re: Hate the swingarm
Post by: RichardL on 24.08. 2020 22:28
Sawing a couple of slots along the length should allow you deform it inwards with a drift enough to degrade the strength of the corroded adhesion.

Richard L.
Title: Re: Hate the swingarm
Post by: berger on 24.08. 2020 23:06
just for laughs get a sense of humor if you haven't got one yet...….. *lol*  you've melted the outer bush sleeve to the swing arm tube *countdown* >:D *work*
Title: Re: Hate the swingarm
Post by: Truckedup on 25.08. 2020 01:49
 Using the torch I carefully  sliced the two outer sleeves , a long drift and hammer, they are history . There's a spacer sleeve in the middle that won't  move, probably best to leave it there..
    I'm thinking of using Delrin for bushings. It's tuff stuff used for performance  auto suspension bushings and easy to machine. Need a long spacer tube and thrust washers limit side to side play...
Title: Re: Hate the swingarm
Post by: Peter in Aus on 25.08. 2020 01:58
If you are very good with a oxy cutting torch you can slice the bush with with the oxy, makes easy work of it, that how I do it, not saying that I'm good with the oxy but good enough. *eek*
Peter
Title: Re: Hate the swingarm
Post by: Kickaha on 25.08. 2020 20:40
if you have a workshop convert to needle rollers.
offhand i cant remember  the sizes but worth the work as the beeza handles better as well.
for a cross over shaft inner bearing sleeves fit on the hollow shaft but you have to make an inner spacer to keep everything in place
i convert all mine. face a grease nipple downwards for easy maintenance.

Do the needle rollers you use fit the original ID of the swingarm ?  I'm assuming they are caged ?  what are the inner bearing sleeves from that you you use ?
Title: Re: Hate the swingarm
Post by: edboy on 25.08. 2020 21:52
hi kicka, without going into my garage and measuring everything. i have written down
needle roller o/d 1.25  i.d. 1 inch. bearing b-1616. eu.
inner roller sleeve i.d. 0.804 / 20.54mm  x 1inch
spindle o/d 13/16   0.8125 / 20.637.
i hope thats all correct. check the bearing suppliers dimensions if you can online.
Title: Re: Hate the swingarm
Post by: Truckedup on 26.08. 2020 12:55
Thanks, a large  US mail order supply house has the bearings. I measure the old spindle as .800 The roller tube I might have to fabricate on my lathe..
Title: Re: Hate the swingarm
Post by: edboy on 27.08. 2020 21:52
hello ,  the needle roller inner sleeve fits snug on the cross over spindle . so i would buy those also.
if you have a lathe no problem making a inner spacer .i drilled and tap the swing arm for a grease nipple and you can peg the spacer that way if you like. you should i.d the spacer to give extra support for the cross spindle and possibly spiral for grease path. the needle rollers and swing arm will float on the spindle when bolted together so you wil need a pair of outer spacers for shimming. for my tribsa with modern tyres i remember using 2  x 1 inch needle rollers either side for top handling . with bearing suppliers giving dimensions online the choice is yours. however from experience with u.k. weather ,using a suzie i would strip and regrease every 2 or 3 years. and materials and workmanship is your responsibility. talk and blog is cheap.
Title: Re: Hate the swingarm
Post by: Kickaha on 28.08. 2020 21:19
hi kicka, without going into my garage and measuring everything. i have written down
needle roller o/d 1.25  i.d. 1 inch. bearing b-1616. eu.
inner roller sleeve i.d. 0.804 / 20.54mm  x 1inch
spindle o/d 13/16   0.8125 / 20.637.
i hope thats all correct. check the bearing suppliers dimensions if you can online.

Awesome, thank you very much
Title: Re: Hate the swingarm
Post by: Truckedup on 06.09. 2020 12:42
 I fabricated axles and bushings.......One more question... the swingarm axle tube has what appears a spacer stuck in the middle. The parts book doesn't show a spacer...Is it a spacer or is the center of the tube a reduced diameter? 
Title: Re: Hate the swingarm
Post by: bsa-bill on 06.09. 2020 16:05
Quote
the swingarm axle tube has what appears a spacer stuck in the middle.

Mine has too, I assumed it was a stop for the bushes and it did workout that way for me, but from a thread long ago I think was not the case in everyone's S/A, once again differences in the same thing
 
Title: Re: Hate the swingarm
Post by: Swarfcut on 06.09. 2020 19:56
 The silentbloc bushes used in automotive applications are usually symmetrical in that the inner steel tube is only slightly longer than the outer. The BSA version looks like a "special", where the inner tube extends  to the centre line of the swinging arm, and abuts with its opposite number.

 With some sort of central spacer, standard size bushes may have been used. After all BSA would have sourced far cheaper industry standard bushes to cut costs if they could.

 Worth checking if anything in common use will fit.

 Swarfy.

 Additional. Is BSA Bill's a solid, early type spindle, or a later brake cross shaft type with a hollow tube spindle and thin wall bushes?
Title: Re: Hate the swingarm
Post by: morris on 06.09. 2020 21:37
My swingarm (hollow shaft) has a reduced centre. Found that out when trying to press out the bushes...*problem*
In the end I burned out the rubber, collapsed the outer tubes inwards and drove them out from the other side
The frame is ‘58 but the whole bike is a mix ‘n match of anything produced between ‘58 and ‘62 so not sure what year the swingarm might be.
Title: Re: Hate the swingarm
Post by: bsa-bill on 06.09. 2020 22:09
Quote
Is BSA Bill's a solid, early type spindle, or a later brake cross shaft type with a hollow tube spindle and thin wall bushes?

Mine is the later hollow spindle type
Title: Re: Hate the swingarm
Post by: Truckedup on 07.09. 2020 05:11
  Here's the bushing set up I   made. The frame is a 1961.
Title: Re: Hate the swingarm
Post by: bsa-bill on 07.09. 2020 10:32
Quote
In the end I burned out the rubber, collapsed the outer tubes inwards and drove them out from the other side
My method too morris with the exception I drilled out the rubber
Title: Re: Hate the swingarm
Post by: tomkilde on 03.01. 2021 14:45
I'm getting ready to send the frame and swingarm of my A10 to be media blasted and powder coated.  Per the attached photo, one end of the swingarm is open.  I don't think this is a problem functionally, but every photo and drawing I've seen shows both ends closed.  Before I start looking for someone to repair it, I'd like to ask the forum experts to confirm that this wasn't some rare and valuable optional BSA feature that I should preserve.  The frame has a 1954 serial number.

In case you were wondering, yes, the spindle was completely frozen.  I spent two weeks trying to loosen it with penetrating oil, heating and freezing, various hammers and homemade pullers.  Nothing worked, and I ended up cutting off the ends with a hacksaw.  Now I need to work on the bushes...
Title: Re: Hate the swingarm
Post by: berger on 03.01. 2021 15:13
I will stick my neck out and say its been sliced
Title: Re: Hate the swingarm
Post by: tomkilde on 03.01. 2021 15:47
Also, is it safe to assume the two brackets for attaching a chainguard are supposed to be identical?
Title: Re: Hate the swingarm
Post by: tomkilde on 03.01. 2021 16:34
Sorry, meant to say "similar" not "identical".  Looking at photos of a 42-7730 chainguard, the distance between the holes is clearly different when comparing the front and rear mounting points.

My A10 came with an aftermarket chainguard fastened with a complicated set of custom brackets and straps, none of them using the original chainguard mounting points.  I'm just trying to sort out how to put it all back together correctly.
Title: Re: Hate the swingarm
Post by: JHG1958 on 06.01. 2021 21:34
Tom

It looks like your swinging arm has had a hard life.  My Chainguard brackets are similar to each other and the better one of yours.  Mine have been bashed about a fair bit probably when the chain came off (lots of times?).  Just about usable.

If I was you I would get a Chainguard and then weld a new bracket to fit the holes.

my rear wheel is off at the moment so I will get a photo tomorrow.

Photo attached.  You can see the front bracket is smaller than the rear one.
Best of luck 
Title: Re: Hate the swingarm
Post by: tomkilde on 25.01. 2021 01:30
I found a bike shop with a really great welder who was able to re-create the missing piece on the end of my swing arm.  I also had him cut off the old, mangled chain guard brackets.

I was able to grind out most of the rubber in the swingarm bushes with a hole saw, then fabricated a puller to remove the inner bushes together with the remnants of the spindle.

Still working on the outer bushes.  Hoping to get this thing to the powder coating shop soon.