Swing arm spindle

ilikevelos said:
I am not understanding why you think the Kegler clamps are good but the "NCNO solution" is bad. By NCNO solution, I take you to mean nuts welded on the pivot tube in the approximate location of the Kegler clamps sold by NYCNorton. They both convert the original geometry to a better geometry. From memory, the original Norton cradle had a fastener in the center of the top of the pivot tube, perpendicular to the rocking forces imparted to the swingarm. Both the clamp and nut solution move the screws to a similar location in parallel to the forces and offset from the pivot center so that they are better able to resist the rocking. These are both improvements. In my opinion, the Kegler clamps principal benefit is that they can be installed on the cradle while in situ since no welding is required. Why do you think one is good and the other bad?

The use of grease in the spindle is obviously bad and neither solution can repair previous damage. The principal advantage of the Kegler clamps is that they can be installed with less disassembly and are a fine product. However, welding two nuts to the cradle has the advantage of being less visible, an objective I prefer in my useful mods. What am I misunderstanding?

Best to all.
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The NCNO solution would be fine if all I said was accounted for:
1) Replace the spindle with the MK3 type that has flats
2) Drill to align with the flats with the spindle properly installed
3) Weld without distortion

For all solutions, not just NCNO do it before there is damage to the cradle.

IMHO, installing either solution without removing the spindle and without cleaning up the burrs caused by drilling is unprofessional and a mistake.

My guess is that your misunderstanding is hearing the end without hearing the reasoning and most likely not having to deal with the aftermath.

IMHO: You cannot improve the geometry! A correct cradle and spindle have the correct geometry. Clamping can maintain that geometry or distort it, not improve it!

In a perfect world, when I build bikes, I would like to use MK3 swingarms and Cradles - not a real option. 75% of the bikes I build are Combats because that's what people ask for. The cost of upgrading to even the better pre-MK3 swingarms is normally something people don't want to pay for. I look for, buy, and restore certain parts such as cradles. About half are a waste of money and get recycled. The rest are just fine, and it ends up costing the customer WAY less than a new cradle. If someone wants to pay for the clamps, I will install them but only if using the new spindle/bushings kit which is already expensive. I will not weld the cradle tube even though as a part of the process the cradle is blasted clean to bear metal in most cases.

I'm happy that you're happy and point was not to start an argument, just to show/tell more about it all. People listen to what people say here and hearing only the good causes me LOTs of phone calls asking why things went bad and what to do about it.
 
kommando said:
The two welded nuts allow two bolts to push the spindle into direct contact with the cradle tube restoring the factory fit, but they do not add to the strength of the tube so if it wallows out a bit more you have to readjust the bolts. The Kegler has the two bolts but also clamps the OD of the cradle tube and adds strength, so much less likely to wallow out again.
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Agreed, as long as the Kegler bolts are tightened evenly and fully. Tighten one all the way and then the other and the spindle is most likely out of line, especially with a very worn cradle. The ones I've checked were not actually worn in the center, but at both ends - therefore actual wobble, not back and forth so any solution could make the spindle not perpendicular to the cradle and therefore the swingarm not in the correct alignment.
 
MexicoMike said:
I wonder if roller bearings are an "upgrade." It seems a poor choice for that purpose. A bushing would have a greater surface area for the load AND, since there is no rotation involved at all, there is a greater chance for roller wear because the same rollers are taking the load in the same position all the time. They don't ever rotate so the point of contact on each of the few rollers that bear the load remain the same.
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The bushings don't move either. And the load is in the same position all the time as you state.
I have never had success with keeping 140 wt oil in the bushings. It always leaked out past the O-rings. I tried using shims between the swing arm and dust cover to bring it within 0.005"
between the rear engine mounting. I've tried Quad rings there as well to no avail in stopping the leak. There is just too much movement in the swing arm and engine rear mount going on when riding the bike. Your centre stand always has road grit an oil on it. and you fill up that hollow swing arm once again. Its like a dog chasing it own tail. "Local entertainment". Your mileage may vary.
 
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CanukNortonNut said:
I have never had success with keeping 140 wt oil in the bushings.
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The bushings are made from oilite which is a porous bronze, the oil gets sucked into the bush by osmosis when soaked in oil and then is slowly released over 6 months or so. So as long as you fill the reservoir every few months the bushes will be replenished in a few days. The oil reservoir does not to be permanently filled so let it leak, its much more important to fill regularly.
 
kommando said:
The bushings are made from oilite which is a porous bronze, the oil gets sucked into the bush by osmosis when soaked in oil and then is slowly released over 6 months or so. So as long as you fill the reservoir every few months the bushes will be replenished in a few days. The oil reservoir does not to be permanently filled so let it leak, its much more important to fill regularly.
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It worked but it leaked so you put up with it. My point is that the O-rings don't work. It was a poor engineering design from the get go.
 
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"From the perspective of maintenance costs, due to the built-in self-lubricating structure, Oilite Bushings basically do not need to replenish any lubricating medium after installation, which greatly reduces the maintenance workload and repair costs. Bronze bushings and plastic bushings require regular replenishing of grease, which not only increases labor and material costs, but improper operation may also cause equipment damage."

Read more: https://fhdbearings.com/blog/oilite-bushings/

Most authoritative and clear site I can find on the subject. I wish I could find a scientific or engineering paper not related to a company but have not.

With this, I'm out.
 
Oillite bushings were developed specifically for places where routine lubrication was not possible or difficult. I don't know if Norton used "Oilite" bushings or just plain bronze or brass bushings. Since they included an oil fitting, I assume they were plain bronze or brass bushings rather than Oilite (or Oilite-type bushings from some other manufacturer).
 
Swing arm spindle

Just get a MK2A-MK3 swingarm and spindle, Do the Kegler mod, Install some Ertelyte bushings, epoxy the welsh plugs, and call it a day.
 

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marshg246 said:
Agreed, as long as the Kegler bolts are tightened evenly and fully. Tighten one all the way and then the other and the spindle is most likely out of line, especially with a very worn cradle. The ones I've checked were not actually worn in the center, but at both ends - therefore actual wobble, not back and forth so any solution could make the spindle not perpendicular to the cradle and therefore the swingarm not in the correct alignment.
Click to expand...

This is because the center bolt acts to resist movement in the middle of the tube, so the swingarm lateral force works the ends of the tube ends bit by bit. And since the center bolt holds the axle/spindle and the swingarm grabs that spindle on both sides, any wear to one side induces equal and opposite wear on the other side. If you were only racing on a race track that only has turns in one direction (Oval race track, go fast turn left) then I would imagine that you would wear the swingarm tube pretty unequally, and hence the swingarm with kegler clamps would not be well aligned, but that's not the case in roadriding. The truth is that I doubt anyone besides that "world's straightest commando" guy has ever taken a new cradle to a granite table to measure the precision of it. I would suggest that the lack of play in the swingarm tube far outweighs any microscopic misalignment imperfection in the swingarm tube angle...

As I said previously, I've chased my perceived wiggle for years on the same bike, methodically going through each system and improving it where possible. It wasn't until I read about the kegler clamps, then made my own set and installed them that the wiggle all but disappeared. And as I also said previously, that very last bit of very small wiggle turned out to be tire sidewall flex and a few extra lbs of inflation cured that last little bit. I was actually pretty surprised at how much better my bike handled afterward, because Denis Cavilier used to rant and rave about how a well set up commando handled so incredibly well, and my bike always had that wiggle back in the day no matter how tightly I adjusted the isolastics so I was skeptical of his opinion. Little did I know that it was my swingarm tube that caused my issue. I had even gone so far as to change out good swingarm bushings for new bushings hoping to eliminate the wiggle. I have no doubt the kegler clamps work well, without having to replace the cradle because of the change in performance of my own bike which had quite a bit of swingarm tube wear.

The idea that a person can't diagnose a problem or wear of a part, then design and modify the part to work correctly, rather than just call the part bad and buy a new factory part isn't a lesser solution in all cases. As I said, I doubt you or anyone else here has measured how squarely mounted or how perfectly straight a swingarm tube is on a new cradle from the manufacturer.

This issue is a known problem of early bikes like the 70 model year bike that was the topic of this thread. Being a longtime owner of a '70 model, I am familiar with the issue and have fixed it without buying a new cradle. If the OP wants to fix it by buying a new cradle, then he might want to buy a late model cradle so he can mount a late model center stand because the '70 center stands mount on the frame cross member and in a word,....... Sucks... where as the later model stand mounts on the later model cradle and is a much better centerstand by all accounts.
 
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I rebuilt my 72 750 swing arm to use the 850 MK3 spindle with flat sides and cotter pins. I cut the center tube and welded in the cotter pin tubes according to Norman White and Ol Britts. What I didn't do is modify the end caps, seals, and rod to the 850 MK3 welch plug oil seal and lubrication system with the oil wicks. I filled the cross tube with oil and now have oil leaking out the cotter pin tubes. It now makes sense that oil would leak there, but can anyone confirm that you have to modify the oil lubrication system to the MK3 design if you do the MK3 spindle upgrade?
 
avanderveen said:
I rebuilt my 72 750 swing arm to use the 850 MK3 spindle with flat sides and cotter pins. I cut the center tube and welded in the cotter pin tubes according to Norman White and Ol Britts. What I didn't do is modify the end caps, seals, and rod to the 850 MK3 welch plug oil seal and lubrication system with the oil wicks. I filled the cross tube with oil and now have oil leaking out the cotter pin tubes. It now makes sense that oil would leak there, but can anyone confirm that you have to modify the oil lubrication system to the MK3 design if you do the MK3 spindle upgrade?
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No you don't but it will reduce the leak, as the bushes are oil absorbent and retain this they only need to see oil every few months, so the oil leaking is ugly but does not harm anything as long as you top up every say 4 to 6 months. As well as the seals you also need the rubber caps for the cotter pins
 
kommando said:
No you don't but it will reduce the leak, as the bushes are oil absorbent and retain this they only need to see oil every few months, so the oil leaking is ugly but does not harm anything as long as you top up every say 4 to 6 months. As well as the seals you also need the rubber caps for the cotter pins
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That's what I do with mine after I converted my cradle to take the MK3 cotterpins
The main reason I keep the swinging arm pivot topped with oil is to stop the pin corroding
Although since I have stopped riding on salty winter roads it's not so much of an issue
 
marshg246 said:
Assuming you used new o-rings and all surfaces are smooth, it should not leak. Be careful tightening that long thin bolt - too much and it breaks, too little and you have leaks. Generally, if you look at the drive side, the nut/sealing washer will be about flush with the swingarm, and the other side will be out further.

If you replaced the "oil nipple" on the timing side with a new one from AN, remove it! They are supplying a standard auto parts store grease nipple and the threaded part is WAY too long. Just fought this last week! It is preventing the seal from happening. You can still use it, but use three 00.0203 FIBRE WASHER 1/4"(06.7620)(NM11775)(NM20621)(A2/722)(B2/613) and blue thread locker to install it.

AN has been informed but I haven't heard back yet.

In the first picture, the original is on the bottom, the AN version is in the middle, and the local auto parts version is on top. The second picture shows how far it can screw in until it hits the edge of the spindle - the AN spindle kit was used along with new AN end caps. Once it hits the spindle, more tightening moves the top out causing the end plate to not lie flat and leak. The third picture is looking through the hole with the center bolt tightened enough that is does not leak.

As L.A.B. says, the spindle does not need to be 100% full. Even if it is, the "oil nipple" hole is slightly above the "fully filled" parts of the spindle.

IMHO, the "oil nipple" is silly. If all the seals work and the locking screw is installed, there no reasonable way to pump in oil as there is nowhere for the air to go. So, when building I leave the oil nipple out, fill through the locking screw and once full put the nipple and locking screw in. I do not pre-soak the bushings. By the time the bike is ridden the oil will have impregnated the bushings and there is still plenty in there if a slight leak happens - normally doesn't if properly installed.

View attachment 116266View attachment 116267View attachment 116268
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I heard from AN the other day they have corrected the oil nipple problem and have the correct ones are for sale now.
 
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I don’t put oil in the swingarm spindle, but drilled and tapped the top of both sides for tiny oilers.
Fill with a few drops 2 -3 times a year and all is well.
No leaks.
 
At the risk of taking this thread in a different direction....
A while ago I helped a friend remove a swingarm spindle from his Commando.
Previously he had tried to drive, push, heat, pull, pound, and generally remove the spindle from the cradle. I wasn't there for this but everything he tried made sense. But no success.

As a last ditch effort, the cradle was removed from the bike and brought to my place. We used a lot of heat, some heavy duty pullers, and big hammers. Nothing!
The cradle ended up on my hydraulic press. The cradle is an awkward shape, and not the flattest object. But it was as well supported as it could be.
By the time the spindle came out, the cradle was beginning to look like a banana. The friend didn't care as he had a few more to choose from. I on the other hand don't like damaging good parts.

My point, if there is one: Has anybody else had this problem? And if so, how did you remove it without damage?
 

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