SWINGARM BUSHING SPECIFICATIONS

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Considering what a fun job it is I'd say use a sharp reamer with pilot guide and fill with the proper lube. There's too many flex points on a commando to not try to keep the swing arm pivot in the best possible condition.
 
After removing my new bushes and pondering the problem, I decided not to risk them getting completely stuck by using the spindle as a mandrel. The ones I took out were actually quite a good fit, the TS was slightly looser than the DS, but the main issue was a misalignment between them, causing the spindle to be very stiff.
At the same time I'm going to do the collar modification to the cradle to remove any slop there.

Speaking to a good friend who is a turner and a Laverda owner, his suggestion was to chuck the Oilite bushes, make up 2 new from bronze and use grease. Hmm, tempting, but that's not going to solve the original misalignment problem.

It's no big deal to buy an adjustable reamer, but to try to find a piloted reamer is actually difficult, unless I spend a great deal of money. Is it possible to make some form of guide, or is this yet another job to be farmed out?
 
Maybe if a shop had a drill press that could hold swing arm square to axle slots and drill a true path though bushes would get ya sweet alignment but It might be more cost-time effective to get another swing arm. I sent Ms Peels 1st 750 swing arm with a slight tweak that prevented spindle slip in to GT Enterprises to fix but came back still not passing the spindle so gave up and got a 850 boxed type that worked a treat on Peel rough stuff and now Trixie with same greaser rust preventing set up. I suggest silver soldering cradle nuts on for the spindle nail down as welding temps may distort and heat weaken their attachments.
 
The original thread asked for the dimensions of the bush, what the guy has got is a variety of opinions on how to fit a set of bearings. The new bearings and pin are cheap enough to buy new and don't require reaming. just squeeze them in using a vice. If they are tight on the spindle, that's good. I'm guessing that the bloke wanted the dimensions to make his own bushes out of something else, not oilite.
 
gripper said:
The original thread asked for the dimensions of the bush, what the guy has got is a variety of opinions on how to fit a set of bearings. The new bearings and pin are cheap enough to buy new and don't require reaming. just squeeze them in using a vice. If they are tight on the spindle, that's good. I'm guessing that the bloke wanted the dimensions to make his own bushes out of something else, not oilite.
Click to expand...

So you feel that the thread would have been better had it stopped with giving the dimensions then?
Regarding your comments about a new spindle & bushes, have you actually tried this or is it just speculation? In my case, and several other people, new bushes from AN become undersize when pressed in, and no, it's not good that the spindle is tight in the bushes unless you don't care about smooth well functioning suspension.
 
Those snazzy UFO graphite using bushes are sent with an OD of 1.225", for an over secure tight interference fit to me.
 
Just to give an update on my posting, I decided that the existing bushes were probably as good a fit on the spindle s I was going to achieve with a hand reamer, so I carefully cleaned the id on the swingarm ( there was a little paint overspray there that I did not notice before – the PO seems to have done a reasonable good rattle can respray here) and the OD on the bushes. I swapped the bushes over to get the tighter clearance on the drive side and pressed then in. There was a very noticeable reduction in the amount of force required to fit the bushes ( I could actually press them in by hand until about half way in). The result was surprising – a snug fit on both bushes, with no perceptible slop at all.
This plus the 2 collars on the cradle tube has completely removed the rear wheel play that was the original problem. It even holds it’s oil (so far..) Thanks for all the helpful suggestions.

/Steve in Denmark
 
Steve, you ask me If I've tried this fitting swinging arm bushes? Seeing as I've had my Commando since 1975, thats a yes, several times. Why would the guy ask for the dimensions of the bushes if he was going to stick with standard oolite? Anyway, moving on, has anybody considered nylon or other plastic bushes in the swinging arm?
 
A number of serious Nortoneers have tried other non metal bushes but found reasons not to continue though you may be able to make it work long term. What would ya gain but a few oz less? Friction is not the worry factor here, slack and hard spindle surface rust is. What has bugged me no end was finding the old bushes, swing arm and forks or gear box were better fit than new sets, ordered twice just to make sure, ugh. Good for other uses as spacers and drifts so not a total waste.
 
gripper said:
Steve, you ask me If I've tried this fitting swinging arm bushes? Seeing as I've had my Commando since 1975, thats a yes, several times. Why would the guy ask for the dimensions of the bushes if he was going to stick with standard oolite? Anyway, moving on, has anybody considered nylon or other plastic bushes in the swinging arm?
Click to expand...

Yes. a green colored plastic called "oslon" or something like that. worked fine on a Ducati. Lot bigger width of swing arm than a Norton.
tried on a Norton. Some may like this I did not. allowing extra 5% clearence for moisture absorbtion, and a bit more for Murphy's law plus standard clearence left it a fraction too loose for me. it also suffered from no wear but wore the shafts badly.
hope this helps. bradley
 
hobot said:
Maybe if a shop had a drill press that could hold swing arm square to axle slots and drill a true path though bushes would get ya sweet alignment but It might be more cost-time effective to get another swing arm. I sent Ms Peels 1st 750 swing arm with a slight tweak that prevented spindle slip in to GT Enterprises to fix but came back still not passing the spindle so gave up and got a 850 boxed type that worked a treat on Peel rough stuff and now Trixie with same greaser rust preventing set up. I suggest silver soldering cradle nuts on for the spindle nail down as welding temps may distort and heat weaken their attachments.
Click to expand...

the beauty of an adjustable pilot reamer is that you can take out 1/4 thou at a time. You would have to be bloody good to drill that accurately.
 
I am still running the original bushes in my 750, but because of excess play in the king pin, I had an oversize one made up. I reamed out the bushes then forced the oversize pin in the cradle. Its not going to come loose again. I did get sick up topping the oil up, as the "o" ring seal system doesn't work so well, so I fitted an 3/16 id hose from the fill plug to a 30ml bottle under the seat, and it gravity feeds all the time now. ,
 
Mine was about 15thou o/size and hard chromed.
Dereck

ps, not sure what the O had done to my 850 but with Welch plugs in the ends, I could not see where oil was going to be added so I drilled out he centre bolt, brazed a 3/16 copper brake pipe to it and put in a 30ml bottle with connecting 3/16 hose. I just keep the bottle filled up. Who cares about the small amount of 90 oil that comes out. Helps to lube the pivots on my remanufactured centre stands. [ I seem to have seen a picture of those pivot hat bushes somewhere else on this forum in the last 2 days. Might have been in the old britz thing on their starter motor conversion. ]
 
Yeah you me and alot of those before us added swing arm oil reservoirs though I just used a big fat clear tube as easier to fix, route and top off. I've quit the swing arm oil habit now. A chrome spindle wouldn't hardly rust so a good feature down there.
 
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