Mk2/Mk3 swingarm spindle

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grandpaul said:
I would think that if you have a Mark III spindle, the best thing to do would be install the bolt-on sleeves, then drill the holes to align with the Mark III spindle slots! Best of BOTH worlds.
Click to expand...

Does anyone have a pic of a MkIII spindle?
 
grandpaul said:
I would think that if you have a Mark III spindle, the best thing to do would be install the bolt-on sleeves, then drill the holes to align with the Mark III spindle slots! Best of BOTH worlds.
Click to expand...

Way easier to just flip the spindle and not try to line up everything plus I don't think the flats on a MK3 spindle will allow it because of the angles to accomplish this
 
bill said:
swooshdave said:
That is a good price, but what would happen if you used something like this? I think you'd still have to drill a hole, maybe tap it.

Mk2/Mk3 swingarm spindle


Someone else posted this in another spindle thread.

McMaster/Carr
Click to expand...

that is what is started with than a flat milled , hole drilled and taped in one half. it makes an easy repair and IMHO stronger than welding nuts on the cradle. not to diss ludwig but they are easier for the average joe to install as the spindle can be a little hard to drill & tap and still can be done in the bike.
Click to expand...

Ok, here's my question. Feel free to correct me. The idea is that the collars help support the spindle in the swingarm tube because the tube is relatively thin? If I had my cradle (it's still out for painting) I could go look at it, but the spindle is a tight fit in the cradle so what do the two extra bolts actually do? Just lock the spindle to the tube? Are the extra locating bolts really needed? Once you have secured/supported the spindle with two of these clamps, I would surmise that the single stock locating bolt would be sufficient to keep the spindle from turning.
 
swooshdave said:
bill said:
swooshdave said:
That is a good price, but what would happen if you used something like this? I think you'd still have to drill a hole, maybe tap it.

Mk2/Mk3 swingarm spindle


Someone else posted this in another spindle thread.

McMaster/Carr
Click to expand...

that is what is started with than a flat milled , hole drilled and taped in one half. it makes an easy repair and IMHO stronger than welding nuts on the cradle. not to diss ludwig but they are easier for the average joe to install as the spindle can be a little hard to drill & tap and still can be done in the bike.
Click to expand...

Ok, here's my question. Feel free to correct me. The idea is that the collars help support the spindle in the swingarm tube because the tube is relatively thin? If I had my cradle (it's still out for painting) I could go look at it, but the spindle is a tight fit in the cradle so what do the two extra bolts actually do? Just lock the spindle to the tube? Are the extra locating bolts really needed? Once you have secured/supported the spindle with two of these clamps, I would surmise that the single stock locating bolt would be sufficient to keep the spindle from turning.
Click to expand...

the steel used in the cradle where the pin fit's is thin and soft. as the bike is used ( the harder it is ridden the faster it will oblong the hole) it will beat out the pin hole. drag racing will oblong it REAL FAST as you are trying to pull the swingarm forward REAL HARD on just one side from the chain . so the idea is to stop it from oblonging the hole for and aft NOT TO STOP PIN ROTATING. I do not see a lot of worn out swingarm bushing's but mostly worn cradles that is causing loose swingarms and this the fix.

LIKE I posted earlier NOT IF BUT WHEN the pin will get loose in the cradle so FIX IT NOW
 
It's obvious to me that I need to take a careful look at the parts diagram because I frankly don't understand this assembly...the bushings are in the swing arm; the oem 12 o/clock bolt keeps the spindle centered and locked to the cradle so the idea is that the pin is fixed and the swing arm bushings rotates on the fixed pin, right? So it's oem 12o'clock bolt that tends to "oblong" the hole in the cradle tube?

You know, looking at all the things that have to be "fixed," on Commandos - everything from the swing arm to the crankcase breather to the forks, to sleeving carbs, to wet sumping fixes, etc,etc,etc, these must have been really crappy bikes! Yet when I owned my original 71, I raced it/rode it daily to work and other than normal maint/adjustments, never did a dang thing to it to address all these "problems." Heck, I didn't even know they existed. AFAIK, I never had any problems related to all the stuff that now has to be re-engineered.. What's up with that? ;)

I'm not saying this in a critical way because I've certainly done plenty of it myself but it has its amusing side.. :) :)
 
Hi Mike, I am just north of you, in New Mexico. You got it right by naming all the stuff that really should be
improved upon, making a better Commando than it left the factory.
And yes, I have long maintained that at Commando is one of, perhaps THE most, highest maintenance motorcycles
ever built. Period. Now, my statement assumes that the owner really, really does want to ride frequently a
well sorted out, fairly "reliable", Commando that is really nice, but not AS greatly put together as the talented people
at say, CNW, would do!
 
OK, re the swing arm...I just took this pic a few minutes ago. As I said, I pulled the spindle nearly 4 years ago and had forgotten how it was setup and haven't paid any attention since so I had forgotten. The pic shows a couple of hex topped studs through the cradle tube with lock nuts. So this was not factory, I guess, therefore a mod by somebody in the past. HEY, maybe this is the only thing those people at B...uh, er, I mean the dealer I bought it from did correctly...or maybe it was the previous actual owner.

Not original, right? No need to do anything else, right? (probably not right, right?) ;)

Mk2/Mk3 swingarm spindle
 
MM ,
That is the fix !
the nuts don't seem welded , just lock nuts ? .
If so , it could have been done better , but still , one thing less to worry about .
( I!ll take that salt back )
 
highdesert said:
improved upon, making a better Commando than it left the factory.
And yes, I have long maintained that at Commando is one of, perhaps THE most, highest maintenance motorcycles
ever built. Period. Now, my statement assumes that the owner really, really does want to ride frequently a
well sorted out, fairly "reliable", Commando that is really nice, but not AS greatly put together as the talented people
at say, CNW, would do!
Click to expand...

I have found just the opposite. My commando has been pretty much trouble free and VERY LOW maintenance in 25,000 miles. I ride quite a few miles and the norm is any where from 150 to 300 mile days and a few 650 mile days. If a commando is put together RIGHT than it should not require anymore work the most other bikes from that era.
 
bill said:
the steel used in the cradle where the pin fit's is thin and soft. as the bike is used ( the harder it is ridden the faster it will oblong the hole) it will beat out the pin hole. drag racing will oblong it REAL FAST as you are trying to pull the swingarm forward REAL HARD on just one side from the chain . so the idea is to stop it from oblonging the hole for and aft NOT TO STOP PIN ROTATING. I do not see a lot of worn out swingarm bushing's but mostly worn cradles that is causing loose swingarms and this the fix.

LIKE I posted earlier NOT IF BUT WHEN the pin will get loose in the cradle so FIX IT NOW
Click to expand...

Mk2/Mk3 swingarm spindle

Mk2/Mk3 swingarm spindle


I have been thinking about this too much. The whole swingarm setup seems funny, but maybe it's not that unusual (for the Commando). The only reason I can think they did it this way is because of the clearance on the ends of the swingarm. Otherwise you would run a bolt though like most other bikes.

I am correct that the spindle should be a snug fit in the cradle (or spindle hole in the picture)? In fact, if I understand it, the spindle should be locked to the cradle. Does just having the clamps provide enough force to prevent the spindle from distorting the spindle hole or from even moving?

Mk2/Mk3 swingarm spindle


The MkIII is an interesting attempt at locking the spindle. BTW, the MkIII spindle is apparently cheaper. No idea why, seems like cutting two flats in the spindle would be more expensive that drilling one hole (is the hole in the older spindles tapped?).

I wonder if anyone has tried Jim's clamps on an early swingarm with a MkIII spindle?
 
Neither of the swing arms shown look like the one on my '73. Instead of a straight round tube or the straight square tube brace across the arm just aft of the bushings, mine has a dual triangular section with the wide end of each triangle at the left and right arm tubes with a pointy end of each triangle meeting in the middle. The pic in my previous post sort of shows it though not very clearly. So where does this swingarm come from?
 
Mike, the picture above has to be for a 75 Mark 3 because it clearly shows that slots in the spindle, of which no Commandos prior to 75 have, and thus
could benefit from the same method of pushing the spindle forward, as in the concept of the nuts and bolts on your swingarm.
Yeah, someone did the mod for you, good on them! But if the nuts are not weld on the cradle on your bike, can't see how the concept should be trusted.
 
MexicoMike said:
Neither of the swing arms shown look like the one on my '73. Instead of a straight round tube or the straight square tube brace across the arm just aft of the bushings, mine has a dual triangular section with the wide end of each triangle at the left and right arm tubes with a pointy end of each triangle meeting in the middle. The pic in my previous post sort of shows it though not very clearly. So where does this swingarm come from?
Click to expand...

That is the late style, pre-Mark III reinforced gusseting on the swingarm just ahead of the tire clearance.
 
MexicoMike said:
Neither of the swing arms shown look like the one on my '73. Instead of a straight round tube or the straight square tube brace across the arm just aft of the bushings, mine has a dual triangular section with the wide end of each triangle at the left and right arm tubes with a pointy end of each triangle meeting in the middle. The pic in my previous post sort of shows it though not very clearly. So where does this swingarm come from?
Click to expand...

Mk2/Mk3 swingarm spindle
 
"But if the nuts are not weld on the cradle on your bike, can't see how the concept should be trusted."

I agree and I didn 't remember if were are or not from when I pulled the pin. So I just looked. The nuts are not welded. The studs go through the side wall of the tube and screw into the pin itself. The nut is a lock nut to prevent the studs from unscrewing. I could replace the studs with suitable short bolts and it would be pretty much the same as the pic Ludwig posted. I'm not sure why someone decided to use the studs instead of a bolt.
 
When I first bought the 73 Commando 750, I made it run and took it out for a ride. Handling was like herding cats, everything wanted to go in a different direction. It felt hinged in the middle. With the bike back on the lift, the rear wheel could be pushed at least an inch in each direction. The swing arm would contact the muffler bracket bolts and had worn a groove in the swingarm. New bushings, spindle and Heinz Keglers fix solved the problem. I highly recommend it.
Tim
 
The center bolt does nothing to prevent the spindle from wallowing out the cradle on the extreme ends. It acts as a pivot point so that the cradle is wallowed out evenly! Whatever method is used serves to lock the spindle to the cradle so it eliminates play in the swingarm - as long as the bushings are good. I use the welded nut method which came about years ago (late '70s) from Norton News. But if I was doing it now I'd use the collars which are much easier to install and seem to do basically the same thing. A much more elegant solution. The tapped spindle should also work just as well. I think you are good to go MexicoMike.
 
"I do not see a lot of worn out swingarm bushing's but mostly worn cradles that is causing loose swingarms and this the fix."

So is there a replacement "bushing" or something that can renew the worn cradle's "trueness" in holding the pin if the cradle gets worn oblong? I don't see any sort of part in the book that fits in the cradle like a bushing or whatever.
 
MexicoMike said:
So is there a replacement "bushing" or something that can renew the worn cradle's "trueness" in holding the pin if the cradle gets worn oblong? I don't see any sort of part in the book that fits in the cradle like a bushing or whatever.
Click to expand...

An oversize spindle used to be available, I'm not sure if it still is?

[Edit]Yes, it is still available, AN part 06-4077: http://www.nortonmotors.de/ANIL/Norton% ... s-list.php
 
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