Strange Frame

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L.A.B. said:
The Commando S/A bushes are porous (sintered bronze) and once "charged" with oil they remain "self-lubricating" for an extended period. The sintered material doesn't have to be kept constantly "wet" with oil, so all that's required is a little periodic re-lubrication.

If grease is pumped into the spindle gallery, it clogs up the assembly, and the grease won't permeate through the sintered bush structure. I know some people can't get used to the idea of using oil and have modified the assembly to use grease but whether that sort of thing is entirely necessary or beneficial is (in my opinion at least) debatable.
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OK you win.. Now i understand what "sintered" bronze does....The bronze is porous, absorbs oil and retains it for some time so "yearly top ups" would suffice.. Thanks for the input..........
 
Surface finish... polish that spindle as fine as you can. The original spindle was chromed for good reason. Have you searched and read about the "Kegler" mod? VERY relevant, simple fix for a REAL chassis design shortcoming.

Strange Frame


Strange Frame
 
If you need to increase the internal diameter of the sintered bushes be careful, the tool has to be sharp or you smear the bronze closing the pores.
 
I did read what i could find re Kegler Mod... and investigated "split shaft collars" locally.. SFA..

So i cleaned out and honed the cradle tube turned a shaft (.884) to fit the refurbished cradle tube... Then honed out the bronze bushes to accept the shaft at a real tight press fit by hand. Whilst honing each side "individually" i was very concerned about their alignment to each other.. Cos you can see how fancy my tooling is for this fittment. I press fitted shaft to each bush individually for real snug fit, otherwise known down here as "finger in a bum" and fortunately the alignment between 2 bushes was perfect..

Strange Frame



Further to Kegler mod,
Part 1... I can see the only reason for this application is to eliminate the sloop/play between the spindle shaft and spindle housing, to reduce the potential "wandering" of rear wheel alignment by locking it in a fixed position... Is that what it is for, yes or no would be good at this stage..

Part 2... Concours, you indicate "polish" the shaft as much as possible, Why ??? or chromed as indicated somewhere.. Why!!! If the shaft is to be fixed stationary to the cradle by Kegler mod theory it will never move/rotate, what benifit is there to "polish" it apart from polishing it like somebody elses. i will give some extra attention to bronze v's spindle area, but just... Is there another reason?

Part 3... With the mod, the shaft is fixed to cradle eliminating all play at rear axle, good thing and only moving parts are shaft v's bushes that is the "only " wear point..

Part 4... Now that i know that my shaft , cradle and bush items are a a very snug fit with no play, what are the benefits for me to include this mod "now", apart from being easy at this time .

I hope someone can clear up a few of these queries.. Thanks ...

.
 
concours said:
Surface finish... polish that spindle as fine as you can. The original spindle was chromed for good reason. Have you searched and read about the "Kegler" mod? VERY relevant, simple fix for a REAL chassis design shortcoming.

Strange Frame


Strange Frame
Click to expand...

I noticed your swing arm has "gusseting" to the trailing arms.. ? Are they part of a factory issue or a later mod,... Being relatively new to Nortons i haven't seen them before..
 
Part 1... I can see the only reason for this application is to eliminate the sloop/play between the spindle shaft and spindle housing, to reduce the potential "wandering" of rear wheel alignment by locking it in a fixed position... Is that what it is for, yes or no would be good at this stage..
Click to expand...


The mod if to eliminate the belling of the spindle housing, the tube wall thickness is too thin to properly support the spindle and it bells on the ends creating play. The extra support saves replacing the tube with thicker walled tube which would be a major exercise.
 
olChris said:
Further to Kegler mod,
Part 1... I can see the only reason for this application is to eliminate the sloop/play between the spindle shaft and spindle housing, to reduce the potential "wandering" of rear wheel alignment by locking it in a fixed position... Is that what it is for, yes or no would be good at this stage..
Click to expand...

Simple answer, yes.



olChris said:
Part 2... Concours, you indicate "polish" the shaft as much as possible, Why ??? or chromed as indicated somewhere.. Why!!! If the shaft is to be fixed stationary to the cradle by Kegler mod theory it will never move/rotate, what benifit is there to "polish" it apart from polishing it like somebody elses. i will give some extra attention to bronze v's spindle area, but just... Is there another reason?
Click to expand...

It seems to be the spindle that wears in the bush area, rather than the bronze bushes. A hard-chromed standard spindle along with the Kegler mods. would perhaps have been a preferable solution (again, in my opinion) to an oversize one made from (hardened?) mild steel (as the Kegler mod. also does away with the need for an oversize spindle).
 
L.A.B. said:
olChris said:
Further to Kegler mod,


It seems to be the spindle that wears in the bush area, rather than the bronze bushes. A hard-chromed standard spindle along with the Kegler mods. would perhaps have been a preferable solution (again, in my opinion) to an oversize one made from (hardened?) mild steel (as the Kegler mod. also does away with the need for an oversize spindle).
Click to expand...
Click to expand...

You do make it clear to me LAB, thanks... The "chrome" is hard, very hard, so its a good wear surface for the bronze. Gotcha.. Another thought along the same path is that ive seen stainless steel being used as a spindle.. Not as hard (dependent on grade) as chrome but easy to manufacture, guess that why its used...

The original shaft that i removed had no visual wear including "lips" where bronze and shaft meet. though the full length was pitted from rust and floppy in cradle tube...

.
 
olChris said:
I did read what i could find re Kegler Mod... and investigated "split shaft collars" locally.. SFA..

So i cleaned out and honed the cradle tube turned a shaft (.884) to fit the refurbished cradle tube... Then honed out the bronze bushes to accept the shaft at a real tight press fit by hand. Whilst honing each side "individually" i was very concerned about their alignment to each other.. Cos you can see how fancy my tooling is for this fittment. I press fitted shaft to each bush individually for real snug fit, otherwise known down here as "finger in a bum" and fortunately the alignment between 2 bushes was perfect..

Strange Frame



Further to Kegler mod,
Part 1... I can see the only reason for this application is to eliminate the sloop/play between the spindle shaft and spindle housing, to reduce the potential "wandering" of rear wheel alignment by locking it in a fixed position... Is that what it is for, yes or no would be good at this stage..

Part 2... Concours, you indicate "polish" the shaft as much as possible, Why ??? or chromed as indicated somewhere.. Why!!! If the shaft is to be fixed stationary to the cradle by Kegler mod theory it will never move/rotate, what benifit is there to "polish" it apart from polishing it like somebody elses. i will give some extra attention to bronze v's spindle area, but just... Is there another reason?

Part 3... With the mod, the shaft is fixed to cradle eliminating all play at rear axle, good thing and only moving parts are shaft v's bushes that is the "only " wear point..

Part 4... Now that i know that my shaft , cradle and bush items are a a very snug fit with no play, what are the benefits for me to include this mod "now", apart from being easy at this time .

I hope someone can clear up a few of these queries.. Thanks ...

.
Click to expand...
The polishing suggestion was about bushing life, the OEM chrome achieves this.

As mentioned already, the thin wall tube in the cradle MAY "wallow out" again, negating the custom work you've done. Study the MKIII parts diagram at http://www.oldbritts.com and see the solution that was implemented. I feel the shaft collars are elegant in their simplicity. I would still do it as a supporting cast to your new custom shaft. Be sure and steel stamp "O.S." on your new shaft to keep your heirs from swearing themselves to death in the future. :shock: :lol:
 
The actual bush assembly is reasonably long-lasting and usually gives no trouble (if lubricated occasionally). It's the spindle-to-cradle area of the assembly that is usually the most problematic, either the spindle rusts soild, (as you discovered) or, as stated already, the spindle often becomes loose inside the cradle tube.
The 850 MkIII (and late MkII/IIA models) had a spindle positively located to the cradle tube by two cotters, it's just a pity the factory didn't do it sooner although Andover Norton now sells a "cottered" cradle option (066972) for earlier Commandos.

http://www.andover-norton.co.uk/SI%20Frames.htm

http://www.oldbritts.com/1975_g16.html
http://www.oldbritts.com/nor_mk3_75_16.html

The "MkIII" arrangement also has a "sealed-for-life" assembly that requires no periodic maintenance or re-lubrication, and although the MkIII spindle and bushes were reduced in length in order to accommodate additional oil-retaining felt "wicks" (Items 3 & 12) the service life did not appear to have been adversly affected by the reduction in bearing surface area, in fact service life may have been extended if only due to the fact that the sealed system did at least prevent owners from pumping grease into it! :wink:
 
L.A.B. said:
The "MkIII" arrangement also has a "sealed-for-life" assembly that requires no periodic maintenance or re-lubrication, and although the MkIII spindle and bushes were reduced in length in order to accommodate additional oil-retaining felt "wicks" (Items 3 & 12) the service life did not appear to have been adversly affected by the reduction in bearing surface area, in fact service life may have been extended if only due to the fact that the sealed system did at least prevent owners from pumping grease into it! :wink:
Click to expand...

I didn't know the MKIII was sealed. I haven't had a chance to tear mine down yet. So did they eliminate the zirk on the MKIII? If so, when you rebuild it how do you get the lube in there?
 
If so, when you rebuild it how do you get the lube in there?
Click to expand...

The caps are like the engine block caps on the block, they are domed and as you press/hit on the dome they expand to grip the hole for them, you will use new caps when rebuilding and pre oil the cavity. Or drill a hole in the centre of one, tap and crew in suitable bolt for refreshing the oil.
 
dennisgb said:
L.A.B. said:
The "MkIII" arrangement also has a "sealed-for-life" assembly that requires no periodic maintenance or re-lubrication, and although the MkIII spindle and bushes were reduced in length in order to accommodate additional oil-retaining felt "wicks" (Items 3 & 12) the service life did not appear to have been adversly affected by the reduction in bearing surface area, in fact service life may have been extended if only due to the fact that the sealed system did at least prevent owners from pumping grease into it! :wink:
Click to expand...

I didn't know the MKIII was sealed. I haven't had a chance to tear mine down yet. So did they eliminate the zirk on the MKIII? If so, when you rebuild it how do you get the lube in there?
Click to expand...

I read about the gear oil thing here, after reviewing my parts, reasoned RUST must be avoided, thought about others drilling the locating bolt and nippling oil in there, so instead, I rigged a tiny hose in through the plug, extending HALFWAY through the spindles bore, (the tube O.D. is smaller than the bore by a 1/16") and occasionally hook a small funnel to the tube up by the oil tank and let gear oil seep in (and OUT) to keep the felts soaked. It's impure looking, but it will keep the rust from happening, and lube the bronze as designed. E-Z for me.
Strange Frame
 
concours said:
I read about the gear oil thing here, after reviewing my parts, reasoned RUST must be avoided, thought about others drilling the locating bolt and nippling oil in there, so instead, I rigged a tiny hose in through the plug, extending HALFWAY through the spindles bore, (the tube O.D. is smaller than the bore by a 1/16") and occasionally hook a small funnel to the tube up by the oil tank and let gear oil seep in (and OUT) to keep the felts soaked. It's impure looking, but it will keep the rust from happening, and lube the bronze as designed. E-Z for me.
Click to expand...

That's sounds like a good solution. Can't quite see in the pic tho. Are you talking about what looks like a small black hose on the end cap in the pic? Is there one on each side?
 
dennisgb said:
concours said:
I read about the gear oil thing here, after reviewing my parts, reasoned RUST must be avoided, thought about others drilling the locating bolt and nippling oil in there, so instead, I rigged a tiny hose in through the plug, extending HALFWAY through the spindles bore, (the tube O.D. is smaller than the bore by a 1/16") and occasionally hook a small funnel to the tube up by the oil tank and let gear oil seep in (and OUT) to keep the felts soaked. It's impure looking, but it will keep the rust from happening, and lube the bronze as designed. E-Z for me.
Click to expand...

That's sounds like a good solution. Can't quite see in the pic tho. Are you talking about what looks like a small black hose on the end cap in the pic? Is there one on each side?
Click to expand...
Yes, only on the right. (Left abuts primary case). Hose extends to the center, keeps both sides supplied.
 
concours said:
"It's okay to disagree, but when our opinions differ we just have to leave it at that instead of trying to discredit each other. Your opinion is different that's why I said you need not worry about it. Your happy with the way your bike handles. I want mine to be the best it can be. We differ there"
I hope I didn't seem to "discredit" anyone. I'm sure the guy re-machining a frame to +/- .0005" is talented, knowledgeable and qualified to do so. ("lunchtime" sarcasm not withstanding :roll: ) My stance has been on challenging the CHOICE to apply that degree of precision to the bikes frame, and I stand by that viewpoint.
Agreed, difference of opinion, no worries, all good. I did, however, fail to see this was a poster here, who is offering this service. I thought it was someone with access to machinery/skills and putting forth the proposition it's the answer to handling quirks. Had I noticed it was a business, I would not have challenged it, and not interfere in any way with people's perceived need for services. As for your bike being the best it can be, that's a great goal.
Thanks for a gentlemanly discussion. :mrgreen:
Click to expand...

Specifically regarding quote,

"I thought it was someone with access to machinery/skills and putting forth the proposition it's the answer to handling quirks. Had I noticed it was a business, I would not have challenged it, and not interfere in any way with people's perceived need for services."

Feel free to challenge. I've got nothing to hide, the procedure is based on engineering fundamentals. I do have access to the necessary tools/skills to correct the problems with Commando frames - and any other frame manufactured in the same way. What I don't understand is why anyone could get so wound up over a
logical argument, put forward for the benefit of other owners. I've mentioned several times I'm hoping to earn money by offering the service, but I really don't expect to get any orders from the USA for example, just want owners to benefit from the results I've obtained. You need to re-read my post regarding machining to +/-0.0005", I was referring to the accuracy of a typical vertical milling machine in the xy parameters.
 
concours said:
Yes, only on the right. (Left abuts primary case). Hose extends to the center, keeps both sides supplied.
Click to expand...

Ah...goes to the center. Nice solution...not so crude like you said, because some of the others are similar. One I saw was a socket head set screw in the middle extended and drilled out with a hose on it. Bikes still use overflow tubes today, so makes perfect sense.
 
dennisgb said:
concours said:
Yes, only on the right. (Left abuts primary case). Hose extends to the center, keeps both sides supplied.
Click to expand...

Ah...goes to the center. Nice solution...not so crude like you said, because some of the others are similar. One I saw was a socket head set screw in the middle extended and drilled out with a hose on it. Bikes still use overflow tubes today, so makes perfect sense.
Click to expand...

Got the idea from chain saws, other small power equip., if a hose stuffed through a hole seals gas, should work fine for oil.
 
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