I am restoring a 1970 commando Roadster. I have replaced the swing arm spindle including bushing ga and all associated parts. I have filled with 140 gear oil. I am getting slight seepage through one of the seals. Is that expected. As bike is only at frame stage I am contemplating tearing it out and going with roller bearing setup. I am looking for some advice. Much easier doing it now rather than later. I just hate anything leaking on my bikes
Swing arm spindle
- Thread starter Eric1109
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Yes, filling with EP140 is done to recharge the porous Oilite bushes, it's not an oil bath as many people think.
"Dust cover" not oil seal.
marshg246
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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.
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Or fit the later sealed system "seals".
marshg246
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I've never used them. Do they simply replace the O-rings and cups? Do they seal as well?Or fit the later sealed system "seals".
o0norton0o
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The 70 model frame has a few issues that are best addressed as a bare frame.
First, the swingarm tube only had a single, central bolt, where the later models have 2 cotter pin bolts. The single bolt doesn't stop the axle from wallowing out the swingarm tube, but the double bolts secure the axle well. NYC norton sells a premade solution for this which were previously called kegler clamps after the man who developed them. I made my own, and many other people did too before they were commercially available. (I have a '70 commando also)
Second, the side stand is short. Someone came up with a solution that involved welding a tab on the frame to use the late model side stands. I never did this to mine, I usually just carry around something to slide under the stand... (eventually I'm going to make a longer stand)
Thirdly, 70 commando's have a timed breather disc against the primary side of the camshaft. This disc turns with the cam and tries to get rid of the crankcase pressure that 360 twins generate. The timing disc is rudimentary and there are better solutions to that problem then using the 1970 solution. You can search here and read more about that
Fourthly, the lower frame cross member of the '70 blocks the use of the best aftermarket crankcase reed valve ever made,..... so you can't use that unless you do some frame surgery while it's apart..(I wouldn't, just look up the solutions for crankcase pressure and note those people who have 70 models and those are the available non-frame cutting solutions for your consideration.
Fifth, you headstock is 1 degree steeper than later models, and your yoke offset is 3/8" less. Your steering is a little lighter and your trail distance is a tiny bit smaller than later models. I've never used or needed a steering damper. It seems stable enough and handles well enough for me... It's a slight difference, but I don't think it is a flaw in any way.
Good luck, ask questions, use the search function, ignore people who answer your questions by talking about themselves instead of addressing your questions...
First, the swingarm tube only had a single, central bolt, where the later models have 2 cotter pin bolts. The single bolt doesn't stop the axle from wallowing out the swingarm tube, but the double bolts secure the axle well. NYC norton sells a premade solution for this which were previously called kegler clamps after the man who developed them. I made my own, and many other people did too before they were commercially available. (I have a '70 commando also)
Second, the side stand is short. Someone came up with a solution that involved welding a tab on the frame to use the late model side stands. I never did this to mine, I usually just carry around something to slide under the stand... (eventually I'm going to make a longer stand)
Thirdly, 70 commando's have a timed breather disc against the primary side of the camshaft. This disc turns with the cam and tries to get rid of the crankcase pressure that 360 twins generate. The timing disc is rudimentary and there are better solutions to that problem then using the 1970 solution. You can search here and read more about that
Fourthly, the lower frame cross member of the '70 blocks the use of the best aftermarket crankcase reed valve ever made,..... so you can't use that unless you do some frame surgery while it's apart..(I wouldn't, just look up the solutions for crankcase pressure and note those people who have 70 models and those are the available non-frame cutting solutions for your consideration.
Fifth, you headstock is 1 degree steeper than later models, and your yoke offset is 3/8" less. Your steering is a little lighter and your trail distance is a tiny bit smaller than later models. I've never used or needed a steering damper. It seems stable enough and handles well enough for me... It's a slight difference, but I don't think it is a flaw in any way.
Good luck, ask questions, use the search function, ignore people who answer your questions by talking about themselves instead of addressing your questions...
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Am I wrong that all the 750s have the steeper headstock? My combat turns in better than 850s I have ridden. I ascribed that to the feature of the steeper headstock.
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Re the single swingarm bolt. The convention within ncno is to weld up the single bolt hole and weld and drill two 1/4 - 20 nuts within the plane of the swingarm pivot and axle to stabilize the swingarm. This is similar to the clamp system but needs to be done b4 painting and assembly. While I was at it , i placed a nut on the top of the swingarm tube added a tube nipple to it and ran clear tubing with a cap up to next to the top of the oil tank. At oil changes I just top off the tube with oil using a plastic syringe to bathe the swingarm bushings. This is still in beta testing but seems to be working extremely well. Best this is never having to try to oil swingarm through end cap and the silly grease nipple.
I am a big fan of reed valves and whine I have never done this, I would consider running the cam breather through an xs650 type reed valve. I don't know much about the timing disc but remove it or not since the timing is supposed to coincide to maximum crankcase pressure anyway. It has been proven that even a relatively small diameter breather will do the job on a healthy engine when rune though a reed valve.
I am a big fan of reed valves and whine I have never done this, I would consider running the cam breather through an xs650 type reed valve. I don't know much about the timing disc but remove it or not since the timing is supposed to coincide to maximum crankcase pressure anyway. It has been proven that even a relatively small diameter breather will do the job on a healthy engine when rune though a reed valve.
marshg246
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IMHO, the only reason for any of the clamp mods is to get around a worn cradle. If the spindle does not wobble in the cradle you're doing nothing. Of course, if done from the beginning the cradle tube should never become loose.
The NCNO method is not great in my book. You need a new-style spindle with the flats, and then you need to do the welding of the bosses accurately to align with those flats and you need to figure out how to weld without distorting the cradle tube. Fail at any or all of those two things and here's what the next guy faces with an old spindle, deformed cradle tube, and marred spindle:
Pulled it bit by bit adding more spacers. Took almost two hours to get it out and then throw the cradle in the recycle bin. Fortunately, the swingarm was OK.
o0norton0o
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I've owned a 70 commando for 48 years. The single bolt swingarm tube probably works ok for a year or two, then the lateral forces over time begins to wallow out the swingarm tube. Pinning the axle in the tube in 2 spots eliminates the movement of the axle in the tube even after the tube has been distorted.....
If, by worn cradle you mean wallowed out swingarm tube in the cradle than yes, but the cradle itself is still good if you use the kegler clamps on the tube.
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The 850 Mk3 has two cotter pins, the others have one bolt.
They should do at least I can't think why not.
I would assume so if only due to there being one leakage face instead of two with the O-ring.
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Eric,
Have you looked at the kit from British Cycle Supply?It looks like a very nice conversion but is pricey.
If my bike was apart I would seriously consider buying one.On my 74 MarkII I fill mine up with the 140W oil which will leak for about a week. I use the Kegler clamps which have worked well for quite some time.
Mike
I thank that's what is happening my end cap is not sitting flush. I guess I'll change it out.
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Eric,
What Mike is on about is The BCR Roller conversion upgrade for Norton Swing arm. Sold at British Cycle Supply or Walridge Motors. As stated it is expensive but eliminates the Oilite bushes and comes with a new swing arm shaft with 6 roller bearings (3 on each end) with modified end caps and inner bushing plates, + assembly grease . You will never have to see oil weep out of that swing arm pivot point ever again. Plug in/and play.... I bought one but haven't installed it yet. When I pull my primary case off, I'll get around to it. He is Canadian to boot.
www.britishcyclerepair.com
What Mike is on about is The BCR Roller conversion upgrade for Norton Swing arm. Sold at British Cycle Supply or Walridge Motors. As stated it is expensive but eliminates the Oilite bushes and comes with a new swing arm shaft with 6 roller bearings (3 on each end) with modified end caps and inner bushing plates, + assembly grease . You will never have to see oil weep out of that swing arm pivot point ever again. Plug in/and play.... I bought one but haven't installed it yet. When I pull my primary case off, I'll get around to it. He is Canadian to boot.
Swingarm Roller Bearing Conversion | British Cycle Repair
Call to schedule your motorcycles next engine cleaning if you have any of the following issues: if your bike is burning oil, or you are experiencing excessive vibration, or unusual engine noises, or if your engine hasn't been cleaned in five years or has sat for longer than two years.
www.britishcyclerepair.com
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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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Of course, if done from the beginning the cradle tube should never become loose.
Greg, My workshop manual said the spindle is a push in fit [ by hand]. ( I laughed at that as King pins in cars had to be a tight press fit ). In that case it will always flog out.
Years ago I made an oversize one and wound it in using a puller. It will never move again. I also fitted a gravity feed from a 30 mil bottle filled with 90 oil.
The "O" Rings don't seal so well, but the gravity feed keeps it well lubed
Greg, My workshop manual said the spindle is a push in fit [ by hand]. ( I laughed at that as King pins in cars had to be a tight press fit ). In that case it will always flog out.
Years ago I made an oversize one and wound it in using a puller. It will never move again. I also fitted a gravity feed from a 30 mil bottle filled with 90 oil.
The "O" Rings don't seal so well, but the gravity feed keeps it well lubed
marshg246
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Theory verses reality.
Your theory is fine and especially fine with a solidly mounted cradle and that not manufactured correctly. However, with a rubber mounted cradle and a properly made cradle, spindle, and swingarm, the rocking action between the swingarm and cradle should not actually exist so should be so small as to not need addressing for a very long time. That's my reality. Also, like I implied, if done originally like the MK3 or with the Kegler clamps in a spindle/cradle without problem, there never will be a problem. However, adding clamps to a worn cradle can easily make the swingarm/cradle alignment wrong with a rocking spindle locked into place unevenly. That's also my reality.
Yes, I have found cradles that were wallowed out - no, never when I found nothing else wrong.
Once the Oilite bushings are fully impregnated with oil, they do not need an oil bath so the little extra in there from the beginning should cover it for a VERY long time if everything is assembled correctly. Every swingarm I've removed filled with grease has had the bushings badly worn and the spindle at least rusted. In the one I pictured pulling out, even with the NCNO solution, the rear of the swingarm moved side to side a LOT even though the spindle was locked down. The bushings were worn and the spindle in the bushing areas were worn .015" undersized. It had clearly been assembled with grease and then filled with oil. The 52-year-old cradle I replace it with, and all new spindle and bushings has no measurable movement swingarm to cradle. It is highly unlikely that the owner will ever need to consider the swingarm and/or cradle again in his lifetime and it is not leaking at all.
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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 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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When rebuilding my swing arm, I loaded up the end caps with silicone as shown at the end of this article.;
Makes sense to me, as I will probably never disassemble it again. If so, it's not a big deal to dig out the silicone.
