Does the slimline frame pull into the swing arm.

From memory, it's been a bit of a wrangle to fit the swingarms into both of my slimlines, will have to use a spreader when they've had the next paint job.

Hi Steven, have you forgotten the swing arm spacer inside the swing arm between the silent block bushes ? Or maybe the previous owner omitted it. This has the effect of moving the bushes inwards creating a space between the swing arm and the frame ears.

It is sometimes difficult fitting the swing arm to the frame as it is a snug fit. The frame will only move slightly upon tightening the two nuts. If the correct length spacer is fitted you can slide a shim in the gap on one side. The system relies on the steel inner of the bush biting into the frame ears which allows the bushes to twist without the whole swing arm turning on the the inner rod.

Hope this helps

I,m about to remove my Atlas swingarm but pretty sure the steel inner bushes have a protruding shoulder which contacts the frame and centre spacer to lock everything solid allowing the rubber to twist freely as Andrew says.

I wouldn’t try pulling the frame in but you need to check the complete assembly.

All these parts are available new from AN

I would guess that most swinging arm silent block bushes and spacers are as fitted by the factory. They appear almost impervious to destruction and can even withstand the powder coating heat process.

Looks like Steven will now have to press these out; but beware, I bought new replacements that were the wrong diameter, this was many years ago. I went down the Manx conversion route instead..

Good Luck.

should be able to see or use a narrow rod to feel if spacer there??

I have a puller using 16mm studding that I made up for this job. I needed about 3 tonnes I reckoned. If you are NW London happy to lend it out.

The metalastek bushes, and the spacer, are all supposed to be in serious longitudinal compression, so you are supposed to be sitting on the bike when it is torqued up. The swingarm rotational movement comes from twisting the inners of the bushes relative to their outers, not from the bushes revolving on the threaded rod (as you would think). Hence no grease nipples. The holes in the frame become elongated when people misunderstand this.

Please anybody feel free to correct me if I am wrong here.

Steve is spot on about how the swing arm works. When restoring my Atlas the spacer was missing and there was an elongated hole in the frame. This I had welded up and re drilled. I omitted siting on the bike and then tightening the nuts which lock it all up. The result was years of suffering a harsh ride as the arc of the swing arm was restricted. This has now been rectified.

On stripping down my slimline 88 last year, with the bike on the centre stand and rear wheel removed, the clamping effect on the metalastic bushes meant that there was enough resistance to torsion such that, on removing the rear shox, the swingarm did not drop under its own weight.

I will have to remember Andrew's point above when I get round to assembling the bike.

It is supposed to be in neutral condition on a smooth road.  The F Neill book (para 106) says to make sure the shock absorber bolts are tightened first to "ensure that the 'Clayflex' bearings are clamped in approximately the correct rotational position".

I bought some replacements years ago.  Never fitted them - they were obviously too big for the hole, and I realised there was nothing wrong with the originals anyway.

Yes, my Silent Block replacements were also too big.  I wish I had left the originals in on that particular swinging arm,.as they were perfectly serviceable.

But at least I was able to try out the Manx design.

Not broken, don't fix it !