resurrecting a 1973 Commando advice please

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Mofosheee

Mofosheee

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A stray, cannibalized incomplete but mostly there basket case 1973 850 found it's way into my garage. (whew)
It would be easy for me to go down the rabbit hole of big $$$ modifications like I did my XR. I'm not a fan of the isolastic mounted engine concept.
So I chose to keep this a basic rebuild. Starting with the chassis at the front end..........
would steering head bearings; 6205-2RS
and
spacer https://andover-norton.co.uk/en/shop-details/17289/bearing-spacer-tube-0700100- be the correct parts?

I'm also looking for a complete swing arm rebuild kit (without going the needle bearing route) and all isolastics.
So when I put my order in, would I be correct to give the supplier my frame number?

Thank all!
Jerry
 
Mofosheee said:
A stray, cannibalized incomplete but mostly there basket case 1973 850 found it's way into my garage. (whew)
It would be easy for me to go down the rabbit hole of big $$$ modifications like I did my XR. I'm not a fan of the isolastic mounted engine concept.
So I chose to keep this a basic rebuild. Starting with the chassis at the front end..........
would steering head bearings; 6205-2RS
and
spacer https://andover-norton.co.uk/en/shop-details/17289/bearing-spacer-tube-0700100- be the correct parts?

I'm also looking for a complete swing arm rebuild kit (without going the needle bearing route) and all isolastics.
So when I put my order in, would I be correct to give the supplier my frame number?

Thank all!
Jerry
Click to expand...
year should be enough.
 
Check out the web site at Oldbritts.com

You can pull up the bike by year and then look at various parts groups with blow up illustrations. You can learn a lot about your bike and what bits it has by looking through this and comparing to other years you get an idea of what range of parts fits your machine. Andover-Norton also provides this along with photos of most of the parts, but shipping is of course from England rather than Washington state.
 
Mofosheee said:
Starting with the chassis at the front end..........
would steering head bearings; 6205-2RS
and
spacer https://andover-norton.co.uk/en/shop-details/17289/bearing-spacer-tube-0700100- be the correct parts?
Click to expand...

Yes. Same bearings and tube used from '1971' to the end of production (850 Mk3). The correct upper and lower yokes/trees for an 850 frame should both be marked 'ANG' on the underside.

Mofosheee said:
I'm also looking for a complete swing arm rebuild kit (without going the needle bearing route)
Click to expand...

If you have any existing parts then they should be the 'long' spindle and long bush parts which are available separately or as a kit.

Note that the latest spindles have two machined flats that the old spindle probably won't have.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

Mofosheee said:
and all isolastics.
Click to expand...

I suggest you fit the vernier pre-Mk3 front conversion kit and rear vernier kit as they are easier to adjust.

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
(No machining of the front mount is required to fit this pre-Mk3 conversion kit.)

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk


Mofosheee said:
So when I put my order in, would I be correct to give the supplier my frame number?
Click to expand...

Assuming the (matching?) frame plate*/engine/gearbox number is 300000-307311 then use the '1973' parts diagrams.
andover-norton.co.uk

Andover Norton Spare Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Genuine Andover Norton Parts created from the original drawings.
andover-norton.co.uk


*You may find there is a 6-digit number on the certification plate (if still there?) which would have matched the engine and gearbox numbers originally and is the number to use for parts, however, there is often an additional non-matching *850*F1xxxxx* frame number stamped directly onto the headstock.
 
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Another question please................

My direction is that of rebuilding the chassis before starting on the engine. Would I be making a mistake or more work for myself if I were to install the swing arm in the transmission cradle then mount the assembly to the frame.
 
Mofosheee said:
Another question please................

My direction is that of rebuilding the chassis before starting on the engine. Would I be making a mistake or more work for myself if I were to install the swing arm in the transmission cradle then mount the assembly to the frame.
Click to expand...
I don't do it that way. IMHO it's much better to put the engine and gearbox in the cradle, put them on their side, and lower the frame over them. Read through this: https://www.gregmarsh.com/MC/Norton/Norton_1974.aspx - about 1/2 way through you'll see what I mean.
 
I go with the lay the bike on its side method used a nice big piece of hard insulation foam on the floor. Power unit in its cradle. Much easier to build the engine up free and clear on the bench too.
 
Onder said:
I go with the lay the bike on its side method used a nice big piece of hard insulation foam on the floor. Power unit in its cradle. Much easier to build the engine up free and clear on the bench too.
Click to expand...
Thank you too!
 
Pipe insulation on the frame tubes saves the fresh frame paint.
 

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The foam on the frame is good but it adds thickness and that can be a problem, you will rip right through the foam.
I use a few layers of tape and over that thin ally sheet and tape that. Your paint will not be scratched and you dont add
so much thickness.
 
Regarding the swing arm rebuild kit. It was stated by L.A.B. that I should have the long spindle.
The spindle that I received with the bike measures just about 7" long. There are no flats on it and I don't know if it's the long or short.
Not sure the year of the bike. All I have is the frame and engine serial number (306502). I have to suspect that I have a MK1.
(copied from web)
300000 850 Mk1.
306591 850 Mk1A low noise emission model intended for 'Europe

Should I specify MK1 when ordering this kit?
Thank you
 
Mofosheee said:
The spindle that I received with the bike measures just about 7" long. There are no flats on it and I don't know if it's the long or short.
Click to expand...

= Long (6.96"): https://andover-norton.co.uk/en/shop-details/15274/swing-arm-spindle-std-dia-6-96-long-
Mofosheee said:
Not sure the year of the bike. All I have is the frame and engine serial number (306502). I have to suspect that I have a MK1.
(copied from web)
300000 850 Mk1.
306591 850 Mk1A low noise emission model intended for 'Europe
Click to expand...

Yes, a late 850 Mk1.

Mofosheee said:
Should I specify MK1 when ordering this kit?
Click to expand...

You can do although the 'long' spindle kit would be correct for the Mk1.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

Personally, I'd want to use the later 06.5227 seals instead of the 'dust' caps and O-rings.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

Although you might know this already the pivot assembly should be lubricated with heavy (EP140 etc.) oil, not grease.
 
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Mofosheee said:
Should I specify MK1 when ordering this kit?
Click to expand...
No, you should lookup the part number you need and order that. In this case, if you want all spindle parts, then you should get the MKIII kit. If you want what was original, then just lookup the kit for 73 or 74. To me, the easiest is the Andover Norton site to lookup numbers.

Edit: To use the MKIII kit with an 750 or 850 MK1/1A and many 850 MK2/2A the swingarm will require machining. Look here: http://www.oldbritts.com/38_600206.html for the machining required. I should not have said to use the MKIII kit!

Les has already told you all this but let me do it in a different way:

Your page parts: https://andover-norton.co.uk/en/shop-drawings/5
MKIII spindle kit: https://andover-norton.co.uk/en/shop-details/20729/swinging-arm-spindle-kit-commando-850mk3
Your spindle kit: https://andover-norton.co.uk/en/shop-details/20728/swinging-arm-spindle-kit-commando-1968-74



Call me if you're confused and I'll help: 703-200-4025
 
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marshg246 said:
No, you should lookup the part number you need and order that. In this case,
Click to expand...

13.1744 with long spindle and bushes is the correct kit. This obviously can't be looked up in the Mk1 parts book as the 'kit' wasn't available, only the separate parts.

marshg246 said:
if you want all spindle parts, then you should get the MKIII kit.
Click to expand...

No, he shouldn't as the 'sealed' Mk3 swingarm 'short' spindle and bush kit (with felts and welch plugs*) wouldn't be correct.

*Edit: For some reason, the welch plugs do not appear to be included in AN's Mk3 kit.:confused:
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
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L.A.B. said:
13.1744 with long spindle and bushes is the correct kit. This obviously can't be looked up in the Mk1 parts book as the 'kit' wasn't available, only the separate parts.



No, he shouldn't as the 'sealed' Mk3 swingarm 'short' spindle and bush kit (with felts and welch plugs) wouldn't be correct.
Click to expand...
I stand corrected, as usual. I thought the complete MKIII kit would work in any Commando swingarm. So, now I'm confused. What parts are needed to use the MKIII-type felts and welsh plugs with a pre-MKIII swingarm.
 
marshg246 said:
I thought the complete MKIII kit would work in any Commando swingarm. So, now I'm confused. What parts are needed to use the MKIII-type felts and welsh plugs with a pre-MKIII swingarm.
Click to expand...

To provide the necessary space for the disc felts and welch plugs the Mk3 spindle and bushes were shortened. Late Mk2/2As also had the 'sealed' short spindle/bush assembly with felts and welch plugs but not the cottered cradle so late Mk2/2As had a short spindle with central bolt hole but no cotter flats so there were two versions of short spindle that have now been amalgamated into one therefore the current short spindle fits either late Mk2/2A and Mk3 'sealed' assemblies.

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk


A pre-'sealed' pivot swingarm I believe has to be machined to provide shoulders for the welch plugs.
 
L.A.B. said:
To provide the necessary space for the disc felts and welch plugs the Mk3 spindle and bushes were shortened. Late Mk2/2As also had the 'sealed' short spindle/bush assembly with felts and welch plugs but not the cottered cradle so late Mk2/2As had a short spindle with central bolt hole but no cotter flats so there were two versions of short spindle that have now been amalgamated into one therefore the current short spindle fits either late Mk2/2A and Mk3 'sealed' assemblies.

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk


A pre-'sealed' pivot swingarm I believe has to be machined to provide shoulders for the welch plugs.
Click to expand...
My early MK2A has the through bolt, but I watched a video where the MKIII kit was installed in a MK2A which apparently was a late MK2A. I just re-watched the important parts and he mentioned OldBritts. They have tech page that shows the modification needed to the Pre-MKIII (actual Pre-Late MK2) swingarm. So, shocker, you're right again!
 
marshg246 said:
My early MK2A has the through bolt, but I watched a video where the MKIII kit was installed in a MK2A which apparently was a late MK2A.
Click to expand...

Which video is that?

It would certainly be possible to fit some of the "Mk3" kit parts to a late Mk2/2A because the sealed pivot was introduced on the Mk2/2A, not Mk3, therefore, a Mk2/2A and Mk3 sealed pivot kit or the individual parts are not all the same (unfortunately AN doesn't sell a sealed kit for the late Mk2/2A and is yet another AN oversight).

The Mk3 kit cotter parts (above the spindle in the pic below) would be no use for a Mk2/2A (without the cotter* upgrade cradle for pre-Mk3 models):
*(Not the 'Kegler' mod.)
resurrecting a 1973 Commando advice please
 
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