Swing arm bearing conversion...opinions?

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Have heard there is a way to replace the swing arm bushings with bearings and alliviate the puddle under my bike.....anyone know of a kit, or anyone done such a thing on their own? Or is this just a fairytale? Other solutions to keep the stock setup and stop the leak are also welcome....this is to be my next project....sick of a center stand running with oil and a general mess under the bike.....Thanks!!!
 
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Yes, I've done the needle bearing conversion on my bike. Works great, no more oily mess! :D

You remove the bushings, machine off the flange (it gets reused as a spacer), and press in two caged needle bearings on each side. Grease it up, reassemble, and you're good to go!

I bought the bearings from a local bearing supply house. Not being handy with a lathe, I took the bushings to my friendly local machine shop for flange removal. The whole job cost less than a new set of bushings.

I can look up the bearing numbers if you like...

Debby
 
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Debby-
Perfect timimg! Ready to cure the sloppy swingarm blues on the '73. (Sinceiwas pulling the z-plates for cleaning and polishing anyway). Please do post the bearing #'s. This sounds like a dandy fix!

Many thanks,
Mike
Kansas, America
73 850 Roadster that I'm dying to hear run again
 
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Interesting - needle bearings instead of the stock bronze bushings on a Commando swingarm.

Years ago on Z1 Kawasaki swingarms the trend was to replace the stock needle bearings with bronze bushings. You see needle bearings are not at all tolerant of contamination and lack lubrication. Invariably, any Z1 that was two years or older had rusty, sloppy swing arm needle bearings. So, the "after-market" came to the rescue with bronze bushings, as they tend to be more forgiving in a less than perfect environment.

It sounds like the chief complaint with Commando swing arms is using oil to lubricate the bushings. Perhaps leaving the bronze bushings and installing a grease fitting would be a solution to the oil-leak problem?
 
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I had a Dresda swing arm years ago, fitted to a Y*m*h* and it had tapered roller bearings. I had to replace them several times.

The problem seemed to be that the limited arc of movement was never enough to allow the rollers to roll completely and pick up new grease. The result was that the outer race indented and then rusted (Sealing was simply by an o-ring, not ideal). Rollers are probably best suited to an environment where they can continue rolling.

There used to be a conversion offered in the UK but it involved replacing the "eyes" on the swing arm and fitting quite large bearings.
 

L.A.B.

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Jason Curtiss said:
Sounds like the chief complaint with Commando swing arms is using oil to lubricate the bushings. Perhaps leaving the bronze bushings and installing a grease fitting would be a solution to the oil-leak problem?

Grease does not work with these bearings!
I'm not exactly sure why but it should not be used.
Perhaps people should be concentrating on trying to keep the (EP140) oil in the bearings?
 
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If the current bushes are modified with spiral grooves then grease can be used, without the grooves the grease gets nowhere hence the need for oil.
 
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If you use grease the grease will break down to a thick goo and you will need a sledgehammer to get it all apart when it has all siezed solid! I know, my bike was like it when I bought it. I dont know the theory as I have seen other machines with plain bearings that run ok on grease. It is something to do with the pressure / shear forces on the grease causing it to deocmpose.

Hew, I fill my s/a once a year with chainsaw oil which is a bit thinner than specified, the slow leak along with all the other seeps & general oil mist form the manufacturers original automatic chassis preservation system. The only difference between this and a Jap is that there is not a sticker on the side saying OACPS.
 
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swingarm bearing conversion

I did the bearing conversion on my '74, 850 a while ago,used Timken B-1416 needle roller bearings, one on each side,simple upgrade,I cut down the length of the bronze bushing equal to the length of the needle bearing leaving the flange intact,I opened up the bore of the bushings by approx. .010" so it cleared the spindle, your choice,if you wish to leave the bushing at stock size .. ok,use the bushing to press in the bearing.I made a new spindle and hardened it to 60 Rockewll C scale,a "soft" spindle will get chewed up by the needle bearing,pack the bearings with lithium based grease and " Bob's yer uncle", smooth operation and no trying to force 140wt. oil where it doesn't want to go!.Good luck, ride safely. James.
 
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Here's the details of how I did mine, as originally described to me:

> Doug McCadam has used this method for 20 years to replace the stock
> swingarm bushings. There are two bearings each side:
> Torrington B-148 and B-1416.

> No machining is required on the swingarm, but you need to cut off
> most of a stock bushing, leaving the "hat" part that looks like a
> big washer. Each bearing has one face that is wider and flatter and
> these go together. Press them in from the outside. The wider
> bearing (B-1416) goes in first and it protrudes from the swingarm
> just enough to cover the flanged washer that retains the big o-ring
> and part of the bronze bushing/washer. Don't let it protrude so far
> that it contacts the engine cradle. Grease well before
> installation. The grease stays in place for many years and needs no
> regular maintenance.

The advantage of this approach is significantly increased bearing area. The bearings are inexpensive. They actually cost less than the machine shop work.

Debby
 
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i am glad this thread came up because i have a question relating to it. when i was changing all my oils and fluids for the first time since i owned the bike a friend who "knows britt bikes" was helping me and put grease in the swing arm instead of the 140 wt oil. from what i have read, i know this is not kosher! so...what do i need to do? i am not sure how to get the grease out, or if i need to. cheers, jerome oh yea, has anyone been riding in 40 degrees yet? burrr.......
 
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Boy...are we good at kicking over those cans of worms.......little did I know. Opinions from both ends of the spectrum, and all quite convincing...

I haven't even found 140W here, and I know my oil is too thin. Can see that perhaps the bearing conversion might have a few ticks in it, and the fact that the bearings aren't able to turn enough to wear evenly and therefore might wear notches in expensive parts, might be a reason to stick to bushings. My bushings have lasted a number of years, and they are still tight, but I have only thinner oil in there and it goes in, and goes out...... right down the main stand and all over the floor ....which can't be too environment friendly either.

Maybe since I have now such big doubts as to what to do about this leaking...it would be just better to switch to Norwegen Cod Liver Oil and then when it leaks out all over the road...I will at least not be polluting the river, and I will have peace of mind.......knowing the ants along the way will not have any problems with constipation........
 
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My....... I know it's the weekend and all... but no need to be so crass about it.....that won't make things better.....:(


Grease isn't used, because this obsure...bellyup, but apparently correct about it, motorcycle company and the buyers of their obsure, but kickass British motorcycles......found out that the grease didn't get to all the areas it was needed at, but that oil did .....if you ever bother to take yours apart...you will see that the holes in the shaft are too small, and too few to distrubute the grease to all the places it is needed...you could put a lot more holes in there...but make sure your insurance is well paid up...because I wouldn't want to hang ten in some corner and find out the swing arm shaft has snapped in two because of some mistake in judgement you made in questioning the intelligence of some obsure and bellyup Brit who designed it with only one hole in it, for a good reason.
Oil goes out the holes, which are located on the top of the shaft, and will run down the sides of the shaft and around the whole bushing, insuring all areas are lubed......grease won't.
My question wasn't whether to use grease or oil (there are enough dopes out there that mistake the oil nipple for a grease nipple...for some obsure reason)...my question was how to avoid the lubrication of my garage floor, along with the swing arm shaft. :wink:
 
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Bloody Hell, Hewho I've got to move to Schnitzel land if your weekends start on Fridays. I thought Puerto Rico was the only place that happened. :lol:

Scooter
(the old ways are the good ways)
 
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ludwig said:
about needle bearings : each time you accellerate , all forward thrust is transmitted to 2 or 3 tiny , allways the same needles . must be a hard shaft not to be dented after a few miles .

Pull a spare spindle off the shelf and try to drill a hole in it. I think you'll find it's case hardened. I'll keep an eye on mine to see if wear becomes an issue though.

As for the needle bearings, the GS Suzukis used caged needle bearings just like this. I've owned three of those bikes, with a total of about 100K miles between them. No problems with the swingarm pivots on those bikes.

Debby
 
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HeWho-
Made a quick call to the local farm and home store. they have an 85-140 oil in stock. I'm sure it's used in tractor applications, might give you an avenue to explore in your area. Hope this helps.

Best,
Mike,
Kansas, America
 

L.A.B.

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hewhoistoolazytologin said:
Oil goes out the holes, which are located on the top of the shaft, and will run down the sides of the shaft and around the whole bushing, insuring all areas are lubed......grease won't.

I have done a bit of research now and I think I may have turned up a few things.

The original bushes/bushings are made from sintered bronze (this type which I believe is called 'Oilite'. Sintered bronze would seem to be an excellent material for this type of bearing application.

http://www.oilitebearings.com/eom.htm

http://www.ahrinternational.com/oilite_ ... shings.htm

Sintered bronze is apparently quite porous and it is only necessary for an area of the bush to be in contact with oil in order for the bush to become (and remain) fully lubricated, as the oil will soak right through the bush, so there's no need to run the bearing in a bath of oil to keep a lubricating film between the bearing surfaces.

OIL soaking into METAL! No, I didn't really believe it either!

As an experiment I put a small drop of oil onto a spare unused S/A bush fully expecting it to sit there, I was slightly amazed as I watched the drip of oil DISAPPEAR completely in under two minutes! It soaked into the bush leaving no trace of oil on the bush surface at all! I repeated the experiment and got exactly the same result.

So, all that would seem to be required is to keep the internal assembly slightly damp with oil (the late models have felt oil retaining pads and no way to top up the oil) , no need to completely saturate the assembly with oil to the point where most of the excess leaks out in the belief that bearing lubrication will benefit as a result.

That would seem to explain why oil and not grease should be used with this type of bearing material.
 
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My 74 Commando had the welch plugs in the ends of the swingarm (I think this was a Mk III change) when I bought it. Never had any oil leaking out but when I went to disassemble the swingarm recently, there wasn't much oil in it. The previous owner of my bike had also mistakenly used grease and it was pretty hardened up. So who knows if the welch plugs were actually sealing? They seemed pretty tight and are not easy to get out. You have to tap a hole and make a puller to extract them and this also ruins them.

When I installed the Kegler swingarm fix (the lockring collars) I went back to the Mk II style flat plugs that sit against the side of the swingarm with a thin central bolt between them holding them tight. One plate has an oil nipple in it. It seemed a bit odd when I installed it as it didn't seem to have any oil seal. I has only been installed about a month but it doesn't leak so far, even with 90W oil in it rather than 140W. I am sure that there are other solutions to sealing the oil in there. I think I would vote for sticking with the original bronze bearings and oil and trying to figure out a way to seal it up.


hewhoistoolazytologin said:
Have heard there is a way to replace the swing arm bushings with bearings and alliviate the puddle under my bike.....anyone know of a kit, or anyone done such a thing on their own? Or is this just a fairytale? Other solutions to keep the stock setup and stop the leak are also welcome....this is to be my next project....sick of a center stand running with oil and a general mess under the bike.....Thanks!!!
 

L.A.B.

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Certain people have remarked that they cannot find EP140 oil, but it seems to be easily available in small quantities (1Ltr.) if ordered from a supplier on the Internet.

My own 850 MkIII has the 'sealed for life' setup and it doesn't leak any oil, of course there may be practically none in there, as I've never stripped it out during the time I have owned the bike, which may lend some credence to the idea that the bearings do not need to be constantly filled with oil?
 
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