renewing unusual swing arm bushes on 61 super rocket - what to do?

[mikeb]

An update. I’ve pressed out the bushes and they’re shown in 2nd pic attached – also showing a spacer (and another small broken ring) that was near the centre of the swingarm but not wide enough to fully space the two bushes.

Weirdly, it looks like there’s a tube still in the swingarm (the top pic). I’m not sure if it’s a previous silent-bloc outer or inserted by a PO to go with these bushes – note there’s no way the bush would turn inside these outers – it took a lot of force to press them out and one end had been punched to stop rotation. You can see some stamped lettering – looks like ‘NEW TUBE’ but could be something else. I'm thinking these old bushes aren't worth persisting with as the whole setup needs a re-design.

I better ask before I drive these out (or otherwise destroy them) - Does anyone recognize the tubes as a silent-bloc outer?

Cheers

[morris]

I better ask before I drive these out (or otherwise destroy them) - Does anyone recognize the tubes as a silent-bloc outer?

Judging by the picture, yes they are. You'll have a hell of a laugh to get them out...
Your swingarm will probably also have the smaller diameter "step" in the middle so there's no way of pressing them out from the outside.
To get those tubes out I had cut a series of grooves on the inside with a hacksaw to weaken them and knock in a small purpose made drift between swingarm and tubes to make the tubes collapse inward. I then knocked them out from the inside.

[KiwiGF]

An update. I’ve pressed out the bushes and they’re shown in 2nd pic attached – also showing a spacer (and another small broken ring) that was near the centre of the swingarm but not wide enough to fully space the two bushes.

Weirdly, it looks like there’s a tube still in the swingarm (the top pic). I’m not sure if it’s a previous silent-bloc outer or inserted by a PO to go with these bushes – note there’s no way the bush would turn inside these outers – it took a lot of force to press them out and one end had been punched to stop rotation. You can see some stamped lettering – looks like ‘NEW TUBE’ but could be something else. I'm thinking these old bushes aren't worth persisting with as the whole setup needs a re-design.

I better ask before I drive these out (or otherwise destroy them) - Does anyone recognize the tubes as a silent-bloc outer?

Cheers

According to this thread of mine the swing arm is 1.25” I.d. Which should tell you if the remaining tubes in the arm are the remainders of blocs?

Also shown is a pic that might help you get new blocs installed.

https://www.a7a10.net/forum/index.php?topic=4293.msg29062#msg29062

[Worty]

What morris said!  They are a real *&^%$ to get out.   I had to mash them up one end, heat the swingarm, then try to bash them out against the mashed up bit from the other side.   Genius BSA.

[RichardL]

I sawed virtually all the way through using a Sawzall with just a little scratching of the swingarm ID. I say "virtually" because I don't think it went all the way through at the inner end of the tube, but close enough that collapsing the tube was not a big problem after it was cut.

Richard L.

[coater87]

 I was able to weld short pieces of fitted round stock just inside the bushes.

 It gave me something to press against.

 The welds gave way a few times, but I was afraid to burn the welds in too deep and weld the bush to the swing arm.

 This eventually worked with very little labor.

 If the bushes are brass or some other metal that cannot be welded, yuck.

 Lee

[Greybeard]

[Smugg mode] You don't have this problem with a Plunger frame!  [/Smugg Mode]

[Worty]

Nice, GB.  Very nice

[Peter in Aus]

This may be of some use to some one, the silentbloc inner sleeve  I got for my A10 58 were to long.
Peter

[mikeb]

Thanks Kiwi - a quick measure with the calipers says the ID of the mysterious tubes in the swingarms is 1.16" while the outer of the tubes/inner of the swingarm 1.25". they gotta go!

And thanks Peter for the pic. is that a factory measure or off your own setup? I ask as I compared 3 swingarms side-by-side in the weekend (thanks Rocket Racer) and noted a range of about 3/16" difference in lengths (widths) of the s/a cross sections (ie that holds the bushes). I believe they were all super rocket swing arms - so either they've had some difficult histories or there were some quality issues at the factory.

[Peter in Aus]

Hi Mikeb I got those measurements from some where, I cant remember where, most likely from this forum.
The print out I had was pretty poor so made up a new drawing with same measurements.
Peter

[mikeb]

You don't have this problem with a Plunger frame!

true, GB, I have other problems on my b33, like getting around a corner with the back wheel following in its own unique direction!

[muskrat]

Yep, a young bloke riding behind me on my plunger reckoned it was like watching someone with a hula hoop. But I still beat him to the pub.
Cheers

[Worty]

A squirm, a bounce, a twist and a twang of nerves and my GF tends to get me round most corners depending on how much I'm asking of it.