Swing arm spindle

Camel, Sahara, Kanguro, Coguaro

Re: Swing arm spindle

Postby harrymuffin » 12 Jul 2020 09:54

When I was making the spindels aswell, that bush that you have found is the one to use. However, as NLM wanted a mortgage for new spindels I looked at recovering the used ones which meant that bush would not work. The spindels would need machining down to about 17.5 and they did do bushes whith i/d of 16mm which suited better as i could macine the bore out to suit. There was another alternative which required the outside diameter to be reduced down to 18mm, the options seemed to grow as Imade more of these refurbishments.Talking to Igus, they did some bushes as specials for firms and would have been ideal - right length, but could not sell them to me, I used to buy in 25 at a time whicch made them cheaper, I think there was a limited order then. The only hiccup was that they do not do them long enough, so two would be needed each side but on the plus side you could do away with the shim washer that people tended to lose on dismantling, owing to all the grease that had been gobbed on over the years. The bushes would be just proud of the truniom so would crush when doing up the nuts, to much though had a detrimental effect With the spindel ready to go back in, which should be tight - a light hammer fit, it was best to lightly grease the spindel with silicone grease just to eae the fitting.i even did a set of Webb girder forks as new PB bushes seemed to last if you were lucky 500miles, you just had to adjust everything tight to get through the MoT. As far as I know the chap i did this for has notbotherd to let me know wwhether they worked, probably becaause I bought the bushes and did the work for free.
When I first loked at this business of swinging arm bushes, I had a freind in to Velocettes just as was. He came up with doing away with PB swinging arm bushes wwhich adain would weaar out by the next MoT and found Glacier made bushes that were a direct replacement for the rorinals and did not need to be reamed with a special reammer. The glaciers also were PTFE lind so not lubrication was needed. I bought some for my little K2 I had then (a century ago) but had to make adapter bushes as the o/d was 20mm. I still have that swinging arm on the shelf having gone over to the Igus ones. Hope this helps if anyone chooses to refurbish and forget.
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Re: Swing arm spindle

Postby dunk 1 » 15 Jul 2020 15:12

Hello Harry- just wanted to clarify something, how tight should the pin be in new metal bushes, I wasn't sure whether your post was referring to these or the plastic ones when you said a light hammer fit.
I have fitted mdina bushes and have been trying to find someone to ream them locally to fit my old swing arm pin. Despite living in a supposedly heavy manufacturing area this has proved very difficult. Fitted the bush gap seems to be about17,5mm and the pin18mm. After reading your post I decided to try them with a wooden mallet, which gets them most of the way with a little effort but I cant imaging it actually rotating. more effort is needed when the unworn part of the bearing surface of the pin meets the bush on the way in and this requires significant effort.
So if a tight fit is needed probably what I need is just the shoulder taking off the pin rather than this and reaming,- or does the fit need to be looser for the metal bushes anyway.
Would a new pin be advisable?
Also Rozzguzzi your pin looks the same as my 79 sport - if it is the part comes up as
https://www.mdinaitalia.co.uk/M140417SS.html
Which is unfortunately more expensive than the one that was posted earlier.
Thanks Duncan
dunk
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Re: Swing arm spindle

Postby rossguzzi » 15 Jul 2020 15:39

I have ordered bushes and pin. Not that one as its a SSteel one. Have not got them yet. Will let you know how it goes when I get them.
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Re: Swing arm spindle

Postby harrymuffin » 15 Jul 2020 17:06

Have to start again everything disappeared.
I am not conversent with the Mdina arrangements, whether using PB bushes or 'plastic ones. The originals however, had the sintered iron bushes which shoul have to be reamed out to size using a piloted reamer to ensure that the bushes were in allignment and not scuwilf. The pilot would enter the one bush whilst the other bush would be taken out to size, the reamer would then engage with the other bush with the reduced pilot at size in the done bush,would ensure that the other bushes was perfectively alligned. These reamers were not off the shelf jobbies so would have to be borrowed. The Velo club had one members to borrow.
Normally when using a reamer the hole shoul be about 0.015" smaller than the disired hole and once reamed should give a clearance of about 0.001-0.002" an nice push fit with a bit of grease on. Reaming the PB bushes that the club used to have made would have beem easier to ream. If you have a bush that is 1/5 a millmeter smaller than the shaft you will never get it in, it has got to be reamed. However, it was kown by the uninitiated to drive the spindel in with a big hamer which would skim of just enough for the spindel to go in and hope it was all true. You could get away with haveing the bush bored out to size, fit it and see how much the bush has closed down if any, and problem solved.
When doing mine the bore of the bushes out of the trunions would be looseish(sic) on the spindel, but once fitted would close down owing the the trunions squeezing the bush such that a light tapping from a soft leather hammer would go through the bushes so that once the one end is screwed in and the nut on the other tightened any misallignment would be negated. I advised to lightly grease the spindel or bushes first with silicon grease just to aid insertion. There would be a small amount of stiction if you rotated the spindel but that was desired ,as the tightness would reduce once in operation with the rubbing of the spindel would receive a covering of the original bush thereby having low friction plasic/plastic mating surfaces so no forming of a grinding past from the gob loads of grease and the PB of sintered iron wearing the spidel lo sided. Without knowing what Mdina have flogged you I cannot give you difinitive answer. But, If you have bought a new spindel then I would be inclined to use the Igus M250 plastic bushes 18 x 24. They used to do them in two lengths so you will need four and reduce one or both to equal lengths to fit the trunion which is I think is 50mm long. Once fited the spindel should go straight in with a light tap but certaily not of the sledge hammer or other force. If you realy get stuck send me a email and I will send you some pictures. I have had a number of Morinis with this set upand had no problems the one with around 30,000miles with no wear or play. The main advantage is if you have rearsets fitted you don't have to dismantle to fit the greasse nipple to lubricate or fit one to the trunion. As I have already said -fit and forget and what is good for Jap bikes mustbe good for Morinis.
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Re: Swing arm spindle

Postby dunk 1 » 15 Jul 2020 18:31

Hello Harry - the bushes are already fitted and are phosphor bronze - they were quite loose on the spindle before fitting but have reduced to how I described them - needing some effort but not massive amounts to get them through. I have one local engineering shop that will have a look and see if they can do them if I pop them down - they are quite a big unit but as you say may not have the required specialist tools.
At the moment I am using the old pin but this would need a small amount of material removed to get rid of the shoulder between the worn and none worn part of the pin ( you describe doing this in a previous post). I am concerned as at the moment the fit is tight but close and the removal of this material may mean they are loose or reaming will not be required which as you say can be used to help correct irregularities. It may be worth getting a new pin and reaming the bushes to this without the added uncertainty of the old one added to the mix.
It does help to have the description of the fit we are aiming for as the removed bushes seemed quite loose on the pin.

Rossguzzi sorry for hijacking your post but I hope some will be of use to you as well
Thanks Duncan
dunk
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Re: Swing arm spindle

Postby harrymuffin » 16 Jul 2020 18:58

Sorry for delay replying. As you have a local machinist I would be inclined to ask him to skim your present spindel, guessing from experience down to 17.5mm and knocking out a couple of bushes to suit if needs be in PB and hope the holes line up with a light tap fit, they will soon go sloppy with the fine grinding paste that will be produced - sorry. The above would have been the cheapest option as you do not need stainless spindels waste of money - wrong spec, as the originals were zinc plated and the bearing bits never suffer from corrosion and as for the reduced middle bit, I have never seen any corrosion on the conversions I have done. Other option would be, more cost I know, would be to get four of the iglidur bushes, cut to length Just 2, and use the new spindel. Have a look at the Igus catalogue and the M250 range of bushes should find one to fit as Julian has high lighted.
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Re: Swing arm spindle

Postby dunk 1 » 16 Jul 2020 19:52

Thanks Harry - as I have gone so far down the route of already fitting new phosphor bronze bushes I will continue with it - the old ones were the same and didn't really cause me any issues - (I should probably have kept the ones I removed for the powdercoating). On a hunch today as I was further afield I checked out a bike shop at Staveley near Kendal and it turns out they actually do stuff besides sell and service and have all the reamers etc. As I thought when they had a look they recommended a new spindle as they thought turning down the old one would make it too loose in the new bushes so have ordered one from Mdina. Next time I will try the different option but hopefully that will be some time away.
Duncan
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Re: Swing arm spindle

Postby rossguzzi » 17 Jul 2020 03:36

All good info.
Cheers.
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Re: Swing arm spindle

Postby harrymuffin » 17 Jul 2020 10:44

I thought you had bought a kit, bushes and spindel, then turning them down would have made the set up loose. The idea was to turn the spindel to 17.5ish and then make the bushes with the bore to 17.5ish, you would only need the bushes then and not have to ream the bushes to fit. You could have just kept the original bushes and rotated the original spindel half a turn and put a shim on the inside of the scewed othe end so you do not distort the fram when tightening te nut up. The stainless spindels are too soft and pointless for cosmetics as you cannot see tem. Bushes and anything pressed into a hole will always reduce the internal diameter, that is why you are supposed to then ream the hole. Valve guides are the same however, you can through experience account for this reduction in bore when intially boring the holes.
Anyway, glad you have solved the problem even though convoluted.
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Re: Swing arm spindle

Postby rossguzzi » 15 Aug 2020 08:08

Finally got my package from Mdina. Well even after asking in the email to check that the pin fits the bushes, it does not. Pin is 15mm and bush internal is 18mm.
I will post up part numbers I ordered soon. Haven't contacted them yet. Bugger.
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Re: Swing arm spindle

Postby harrymuffin » 15 Aug 2020 10:08

Dear Ross,
You are doing well, NLM would reply to you that"Well, nobody else has complained"
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Re: Swing arm spindle

Postby rossguzzi » 16 Aug 2020 14:38

Anyone know what outside diam of the bush is meant to be ?

Cheers.
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Re: Swing arm spindle

Postby rossguzzi » 17 Aug 2020 13:08

Looks like I ordered a 250 spindle. For the life of me I was sure it said 500 spindle on the webpage when I clicked it. It seems the only 500 spindles they stock are SS.
As my spindle was worn a bit, I did turn it when reinstalling and there seemed to be no play. Lucky perhaps.
There is a specialist in polyurethanes around the corner. I might ask them if they have poly equal to the ignus mentioned before.
Mining is huge in WA, so it would not surprise me if they do have an equivalent. If they do, I will return the spindle and get mine skimmed down and poly bushes done.
Just as was suggested before. I should have listened.
Cheers.
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Re: Swing arm spindle

Postby rossguzzi » 19 Aug 2020 13:59

So I went to the guys that do poly stuff locally. They said they have similar stuff to Igus M250 plastic bushes. They can make them any size to order. I may send my Mdina stuff back and go this way. Will be a little way off yet. Will post progress.
Cheers.
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Re: Swing arm spindle

Postby 3potjohn » 19 Aug 2020 18:21

That sounds like a plan and at least you can source the material locally. I had a lot of trouble getting my old bushes out and the new ones in, not to mention reaming. If there is a next time I shall look at this solution.
John
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