Swing arm spindle

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.
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.
 
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.
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.
 
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.
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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I have never had success with keeping 140 wt oil in the bushings.
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.
 
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.
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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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.

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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