Swingarm pivot and shims

[900Rebuilder]

Hi All,

I got my swingarm installed at the weekend and found that the pivot shaft is narrower than the width of the swingarm itself. This may be ok as I can see from the manual that there should be a circlip and a rubber plug in there but mine (early style) does not have a groove for a circlip to locate in. Can anyone shed any light on this for me please?

Also the sides of the swingarm which contact the rear engine mount still have powder coating on them which may / may not be a problem. Currently the large spacers are in with no shims and there is no play, but if I were to remove the plastic I'd guess I'd end up with approximately a 2mm to then remove with shims - thoughts on this too please?

I've taken multiple images but Postimages keeps telling me that my jpg's aren't recognised despite me doing nothing different

[Mr Gazza]

Powder coating on a bearing surface is a big no no.
It's going to turn to putty quite quickly as the arm moves in service.
(Obviously with hindsight) the surfaces should have been masked before coating.
Unfortunately those faces will have been grit blasted at best and at worst could have been power sanded.
You'll have to see if it's saveable by removing the coating, checking the faces for flat and square with the pin, then start from scratch with the shims.
I couldn't comment on the pin length, but I do know that single siders use a different length.

[Dukedesmo]

My old swingarm (the one that broke) http://www.ukmonster.co.uk/monster/s...ad.php?t=60544 was from an 851/888 and it was wider at the front than the Monster arm that I replaced it with.

It was as wide as the M900 spindle was long and so, whilst it fit it didn't protrude from the ends of the arm meaning, I couldn't fit the circlip.

This was OK as the bolt clamps it in place until of course the the arm cracked and the spindle slid out, something that wouldn't have happened if the clips were in place even with a broken swingarm.

I seem to recall you saying you had an 888 swingarm? I don't know if they used a longer spindle or just didn't bother with the clips? (maybe they added the clips after a few spindles slid out due to broken arms?).

I do know that the steel arm spindle as per M600/750 is shorter as the arm is narrower due to being made from a smaller box section, how long is your spindle?

As per above, powder coating on the inner surface is no good, it will wear off and then the swingarm be loose. Also, when shimming check the sprocket alignment, mine was well out.

[900Rebuilder]

Thanks all - confirmed my suspicion that something was not right so will remove and remove the pc from the faces - wonder if the shaft is incorrect too so will remove and measure to be 100% and report the size back here.

Yes I beleive the swingarm is the 888 style due to the hugger mounts

Also I've found some tabs on the frame near the rear shock which appear to be for the S shock reservoir mount - this could be very handy if I could locate a genuine bracket for this location

[Dukedesmo]

Looking at the picture, it seems to me that the shaft is way too short. The M900 shaft in my old 888 swingarm sat flush with the end of the swingarm - still couldn't get the clips on but it was at least the full length. I know the M600 swingarm pivot is quite a bit shorter (10-15mm IIRC) and so would sit back inside the swingarm, something that wouldn't help with the load/cracking issue.

The tabs on the frame are, I think on all frames (my frame originated in an M600 and has them). I have an Ohlins shock and originally mounted the reservoir on the side of the frame as per the supplied mounting rubbers but never liked it there so I made a bracket to fit it under the rear as per S models, simply a cut/bent piece of stainless steel sheet and simple enough to make unless you have a genuine one.

Where it was;



Where it is;



I'm sure you'd agree, much neater.

BTW, when you get to fitting the swingarm, if you need the plastic end caps and clips, I have a small stash as when my swingarm pivot slid out I lost one of the caps and could only source them in a pack of 10, similarly the snap rings.

[Dukedesmo]

Further delving and I found this;



Top is M600 swingarm spindle, note there are no circlip grooves and bottom is M900 spindle with grooves and longer.

Looks like you may have an M600 spindle?

[900Rebuilder]

Thanks DD I'll get it out later this week (pulled muscle in back at mo ) and post up the dimensions here.

I'm glad I asked here though as it would have been all too easy to have assembled something that felt right but was in fact a ticking time bomb

Regarding the shock mount I think I will probably make something that fits as your ultimate solution looks much better and when I tried mine in various different places I came to the same 2 locations as you. I did think that the external one might constantly be in contact with my right knee so that would be a major no-no and annoying!

[Dukedesmo]

If you need it, I've got a spare 900 spindle but, it still may not be long enough to get the clips on if the swingarm is like my old one? though it should at least be long enough for full contact.

With the shock reservoir, I never had any contact with it but it was always in the way if topping up oil and for servicing - need to remove to get at the belts and it was prone to getting damaged if the bike fell over but, mainly I thought it looked naff - along the lines of a red bull tin catch tank

The OEM mounting bracket is a simple affair, just uses 2 large jubilee clips to hold the reservoir and, whilst I didn't have one to copy, mine is basically the same thing but in stainless steel, though I used rubber lined 'P' clips rather than jubilee to avoid scratching the casing.

[900Rebuilder]

Thanks for the picture as now I can see it via a large picture it appears very simple and relatively easy to replicate. Might see if I can get a genuine one first as I'm unsure how to make the curved section (but can give it a go!).

Must remember not to pick up the engine on my own next time...

[Dukedesmo]

I made mine flat in that part as it fits the 'P' clip better but if you want a curved one then probably easier to make it from a piece of curved material such as the correct diameter pipe on the basis that it's easier to flatten the part for the frame mount than to curve the rest?

[Mr Gazza]

I've got the original bracket on my Sie. I'll see if I can get a few measurements.

To be honest I think the bracket is a bit over engineered and jubilee clips are crude, even though I have changed the clips to stainless.

I like the idea of P clips, but instead of the bracket altogether. I don't see why they wouldn't be strong enough on their own, bolted into the bracket's holes.
It would save the weight of the (steel) bracket and look neater.

[Dukedesmo]

Problem is, the mounting tabs are on the front of the frame tube close to the spring and so if you simply bolt the 'P' clips on them, then the whole thing sits too far forwards and would foul the spring, plus the reservoir is too long to fit inside the 'cradle' of the frame where it would be anyway.

As such, you'd need to extend the 'P' clips significantly backwards to get it further away, at which point it'd be dancing around on the long extensions unless they were really substantial, so a bracket works better IMO.

Plus, it's not a lot of weight, especially mine which I made from fairly thin stainless (don't know how thick the OEM part is?).

You could always make a Carbon Fibre bracket...

[Mr Gazza]

I hear you. I thought it might be a bit tight.
I like using alloy angle for bracketry. I'm thinking of a bit of unequal angle with the top horizontal leg long enough to give clearance from the spring. Then the P clips bolted to the vertical leg so the bolts wouldn't need to be on the frame hole centres.
The P clips would be stronger hanging that way round too.

I'll probably never do this, but it would get rid of those horrid jubilee clips! Probably an easier way to go in the absence of an original bracket though?

You've got me thinking about CF too..

[Dukedesmo]

My bracket is effectively a strip of angle and with the 'P' clips lower down on the vertical (not quite vertical due to the angle of the brackets) so that the bolts are at the bottom, the top is then cut away between the frame mounts to reduce weight but as it's made from IIRC 1.6mm stainless sheet it's fairly light yet (due to the 90 degree bend) plenty strong enough.

Not the best pics but;





But, yes a strip of CF angle might be a future project...

[Mr Gazza]

Having had a look at the original Sie reservoir I think it's probably hard to improve on it given that it ain't broke so to speak. Perhaps I might try and get the jubilee clip screwheads up in front of the bracket to hide them up a bit and show only the plain portion of the band and maybe give it a lick of paint.
That said I think the angle and P clip idea has legs. It works for you after all.