box section swinging arms

[RALPHARAMA]

I am turning my attention once again to my JMC box section swinging arm, which had taper roller bearings in it. These would have been fine, except that one got lost lost in the office/workshop build by Bob the Builder (at least I'm gonna blame him!). After a bit of investigation I talked to JMC and discovered that they had some imperial bearings especially modified for the task. I have investigated the possibilty of doing the same but it seems prohibitively expensive.

I bought another box section arm off fleabay but it is a bit wimpy in comparison with the JMC, which I've already had powercoated. It however uses ballraces and bushes that actually fit into the the JMC arm nicely as far as outside diameter goes. I am sure I could get another set of ball races cheaply enough rather than scrap the new swing arm just to rob it of it's bearings. With the depth that the JMC is bored I may even get two races each side. Anyone know if this would be a good plan?

[Pigford]

All sounds good, except for the

I am sure I could get another set of ball races cheaply enough rather than scrap the new swing arm just to rob it of it's bearings.

You will CAREFULLY remove the bearings & let me have whats left, in GWO

[RALPHARAMA]

Here's a pic of the donor swinger. I don't like the look of the brackets that fix the shox on. The chain guard brackets have been badly ground off and the bracket for the torque arm isn't there either as it was obviously crafted for a drum brake model.


Having stripped the bearings out I have found that it's innards are identical to the JMC I have and I am wondering if the ball bearings are a retro fit by somneone who couldn't get taper rollers. There have been spacers made to fit the outer races. I wonder if this arm is an earlier JMC?





What do we think? Is this going to be an improvement over the original arm? To use the swinging arm I'll have to make a new torque arm for the brake as the original arm won't fit, unless the original was used with some 'chain' plate type links?
Any pearls of wisdom on this?

[Steve R]

Hi ,

That second swing armI am almost certain is a Dresda Box section arm. If so it should run taper Bearings, You can buy a bearing that fits, I believe its a land rover bearing? It fits the swing arm , but the inner race diameter is just too small by a tiny amount to fit the spindle. I used the inner bearings I already had, cos they were not that bad together with the new outer bearings. I do not know if it would be possible to make the centre of the inner bearing bigger to fit the shaft or not it really is only a tiny bit out.
Dave Degans is the guy that made the dresda arms and he is still around making tritons you will find him if you google, he may be able to advise.

If you need the part number for the bearings I may be able to dig out a receipt.

Regards Steve R

[Taffus]

Hmmm
first one looks like a kettle dresda swinging arm, theres a kettle club meet first wednesday next month will have butchers there if you want
T

[FER]

Only problem I can see is the spacer between the bearings would have to be the exact size needed to avoid side loading the bearings when it is bolted up , same idea as wheel bearings .




fer

[Iain marshall]

First one looks like a Dresda as already said and the other looks like an old mild steel JMC i've got in the shed

[Rich]

Have a look at NAX bearings to see if any fit the bill, they are combined thrust and needle roller

http://www.yuilbearing.com/bearing/need ... eedleNAX(Z)_e.htm

[RALPHARAMA]

Hi Rich

You sure about that URL? All I get is a blank page with a load a chinese text.

[RALPHARAMA]

Hi Rich

You sure about that URL? All I get is a blank page with a load a chinese text.
Thanks, Ralph

[Iain marshall]

I copied the hole link,went to google and pasted it and came up with the site.But when i copied the address and put it on here i got the same as Rich

[Rich]

As Iain says you have to copy the whole lot and paste it into your address bar - don't ask my why! - just one of them computer thingies - may have something to do with the brackets

[RALPHARAMA]

Thanks

Did get on the site. Same old issue .. no bearings for 16mm shaft. O think that combi side thrust with roller bearing is a bit OTT for a sing arm besides there would be some serious engineering to the frame required for some thing to take up the side thrust. I'm tempted to try the bearings that came with the Dresda (?) arm. It may be that someone else thought this was a good wheeze but found out the hard way it wasn't and stuck the remains of a failled experiment on e-bay .. who knows?

The only thing giving me a bit of hesitation if the hard graft involved in making a new brake torque arm.

[Jumbo]

Hi
I have a swing arm, like yours and as Steve R says I would say it is a Dresda too. I bought it to use on a Kawasaki Triple project that is still in the pipeline. There were several bits missing from mine, however I do not think that mine had a tube inside between the bearings. It just had Taper Bearings obviously on each side that fitted inside, with a machined cap/cover that sorted the spacing in the frame. I enquired with BSL (Bearing Services Limited) who said that they could have ordered the bearings. But I was going to get Phil Denton to machine a custom stainless swing arm axle for me.

To resolve the JMC problem as you would prefer to fit that, I would suggest taking it to a machine shop who could either source bearings or machine some parts up. There is a guy on the Triples Forum who is around the Dorset/Somerset area who might be able to help you he repairs cranks and performs machine work. Looking at the photos the bits look like they have been made at a latter date as you can see the machine marks.

[Pigford]

The Tripples chap is known as: h2Chris on the forum http://www.kawasakitriplesuk.co.uk