Is it a Mk 2A or Mk 2 or Mk1A or Mk 1? (2015)

Someone has pointed out this 850 on aussie ebay.

http://www.ebay.com.au/itm/191619719458
Now why would that be a Mk 1A ?
Why not a Mk 1, or Mk 2 ?

and note
http://www.ebay.com.au/itm/191619011775

Good question!

As I understand it from Roy Bacon's Norton Twins, which I admit has several inaccuracies, the Mk 1 850 Commando was the designation given to the 1973 850 models. The 1A version had the plastic airbox and bean can silencers. I have never seen one of these in the U.S., so perhaps they were not imported here.
With the cylinder head change in 1974, this model was designated the Mk 2 and the "quiet" version with plastic airbox and bean can silencer designated as Mk 2A. The 1975 electric start version was designated the Mk 3.

As to the bike in the eBay listing, since it is a 1973 850 model, it would be a Mk 1. Since it has a Mikuni carburetor without an original airbox and is wearing peashooters, it is impossible to determine if it was an "A" model or not. The bean can silencers were often replaced with peashooters.

The 750 Commando series also had such designations, so there is a 750 Mk I up to the last 750, the 1973 Mk V. However, the Mk I, Mk II, Mk III, designations are not as clear as the Mk IV and Mk V.

As I stated at the beginning, this is the way I understand it, and it is entirely possible there is a better explanation.

That sounds very good to me Ron, entirely the way I have seen it writ and quoted.

We are bemused the seller is claiming its an A Model, either Mk 2A or now Mk 1A,
when the beancans and plastic airbox and dzus sidecover are nowhere to be seen.
Perhaps x-ray vision or being clairvoyant helps.
It was imported from the USA too...

Can we verify that Mk1 and Mk1A were built together, the Mk 1A didn't simply replace the Mk 1 ?

Ron L said:

As to the bike in the eBay listing, since it is a 1973 850 model, it would be a Mk 1.

Click to expand...

However, Mk2/2A production started from 307311, so "308771" would be a Mk2 or 2A. Agreed, it doesn't have the usually expected 'A' features-even those more subtle ones-such as the 'A' oil junction block Edit: although it does have the 'A' kickstart lever.

(Hopefully, its new owner will re-route the rear brake cable over the Z-plate! :roll: :shock: )

Is this all listed someplace - accurately ?, LAB.
I know this discussion has been had before, but it still doesn't all seem to be all written down.

Rohan said:

Can we verify that Mk1 and Mk1A were built together, the Mk 1A didn't simply replace the Mk 1 ?

Click to expand...

And were the Mk1 and Mk1A built side by side, or did the 1A replace the 1
Do we know ?

Rohan said:

Is this all listed someplace - accurately ?, LAB.
I know this discussion has been had before, but it still doesn't all seem to be all written down.

Click to expand...

This is verified by the Mk2/2A parts supplement-although the supplement actually says "Covering 850 models after 307311".

Rohan said:

Can we verify that Mk1 and Mk1A were built together, the Mk 1A didn't simply replace the Mk 1 ?
And were the Mk1 and Mk1A built side by side, or did the 1A replace the 1
Do we know ?

Click to expand...

The 'A' models were supposedly intended for the European(mainland) market (initially, although we know the A models also ended up being sold on other markets outside Europe-but there were no US Mk1A's as far as we know?) so it would be logical to assume that the 850 Mk1 and Mk1A variants were built concurrently-as the Mk2's and 2A's must have been.

Edit: Mk1A's were supposedly built from 306591 (I'm not sure that number is verifiable) so 1A's were only in production for a comparatively short time before being superseded by the 2A.

I am new to Commandos, ... And confused. The plate on the headstock of mine sez 8/73 and the number is 307844. Oh. ... And the bike was originally sold in Canada and is still here!
So what Mark is it?
Cheers
Don

Its a MK2/2A, built in Aug 73 and was one of the first 74 model year MK2/MK2A's. The next model year production always started just around the summer shutdown in the previous year. To determine if its a MK2 or MK2A the best way is to look at the battery, if its fitted long way down the bike its a MK2, long way across the bike then its a MK2A, MK2A's can easily be made to look like a MK2 but the battery tray is the least likely item to be changed.

Donald said:

I am new to Commandos, ... And confused. The plate on the headstock of mine sez 8/73 and the number is 307844. Oh. ... And the bike was originally sold in Canada and is still here!
So what Mark is it?

Click to expand...

Yes it would either be a Mk2 or 2A, the original specification would have determined which.

The main features of the "low noise emission" 'A' models would be a black plastic airbox, annular discharge (aka. "bean can", or "black cap") silencers/mufflers, cranked out kickstart lever, battery installed across the frame and LH side panel retained by a DZUS fastener at the lower rear corner, whereas a Mk2 would have a perforated metal airbox, peashooter silencers, etc.

All vestiges of 1A or 2A are missing on the blue bike from Australia. Besides plastic air box and bean cans these also had a different left side cover using a DZUS type fastener. The cover had an indentation at the bottom with hole for the fastener. For some reason there are people that want to use the Mk#A identifier. Mayybe that's all they know for '73 and '74 models.

Whatever model it is, it seems very cheap.

acotrel said:

Whatever model it is, it seems very cheap.

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Its an auction - bidding hasn't finished yet. !
You pay the final hammer price, not a price half way through the auction.

Serious bidders only bid in the last 5 secs of the auction....

Note too that 'reserve not met'

kommando said:

Its a MK2/2A, built in Aug 73 and was one of the first 74 model year MK2/MK2A's. The next model year production always started just around the summer shutdown in the previous year. .

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The auction states it was built 9/73, thats Sept.
Aug is jumping the gun for next years models !?

When did Nortons officially announce the Mk 2 models ?

We note that the factory was building and stockpiling the 850 Mk 1 models,
for quite some months before the (April) announcement.

L.A.B. said:

This is verified by the Mk2/2A parts supplement-although the supplement actually says "Covering 850 models after 307311".

Edit: Mk1A's were supposedly built from 306591 (I'm not sure that number is verifiable) so 1A's were only in production for a comparatively short time before being superseded by the 2A.

Click to expand...

This means there are only a possible approx. 700 of the 850 Mk 1A models,
even if it was the only version they were building. ?
ie not building Mk 1 versions alongside them....

L.A.B. said:

This is verified by the Mk2/2A parts supplement-although the supplement actually says "Covering 850 models after 307311".

Click to expand...

If they started building the Mk 2 models in Sept, from 307311,
and this bike for sale is Sept built and number 308711,

that adds up to building approx 1400 bikes (at least) in Sept.
Is that possible, that sounds like a lot. ?
Going into autumn sales period too....

I've got a pretty early MK2 (307,464) if those production #'s are correct. Hard to believe they built that many in a month when they were only a few years away from closing their doors.

Norton Villiers was moderately profitable. With the 850 anyway, once they got over the Combat debacle.

Until they were forced to merge with Triumph, and things went rather pear shaped....

Rohan said:

kommando said:

Its a MK2/2A, built in Aug 73 and was one of the first 74 model year MK2/MK2A's. The next model year production always started just around the summer shutdown in the previous year. .

Click to expand...

The auction states it was built 9/73, thats Sept.
Aug is jumping the gun for next years models !?

When did Nortons officially announce the Mk 2 models ?

We note that the factory was building and stockpiling the 850 Mk 1 models,
for quite some months before the (April) announcement.

Click to expand...

I was referring to the data from the owner of 307844 who states his is stamped 08/73 so a very early MK2/2A 74 model year, as they liked to time the model year change to the annual summer shutdown in Jul/Aug then I do not think Aug is too early and also this results in the 1400 in one month being 1400 in 2 months. As the factory was still recovering from the Combat mess the build dates being messed around is not unexpected.

By the 80's when I was working in the UK Midlands Auto factories the model year change had slipped to Sept/Oct, this was finalised 6 months before when we sent all the suppliers the final volumes for all their outgoing superseded parts, so 6 months before the change you were committed to a finite quantity of the old model. If there was a strike or a slow-up in sales the original planned change-over date slipped, if sales increased and build rates increased the date came forward as the quantity was unchanged. So in that 6 months a lot could and did change, a big model year change was kept in control and sales told to go stuff themselves if they wanted to change build rates, a minor one with no tooling/line changes was loosely monitored and changes allowed in the eventual changeover date. The change from MK1/1A to MK2/2A would have been a minor one, the MK2/2A to MK3 would have been a major change.

Rohan said:

If they started building the Mk 2 models in Sept, from 307311, and this bike for sale is Sept built and number 308711, that adds up to building approx 1400 bikes (at least) in Sept. Is that possible, that sounds like a lot. ?

Click to expand...

We know the 2/2A serial numbers got to 324xxx, therefore, assuming there wasn't a significant amount of unused serial numbers within the series, it does suggest they built around 17,000 Mk2/2A's in a little over a year, so I don't think a figure of 1,400 a month exceeds the realms of possibility?

Rohan said:

Going into autumn sales period too....

Click to expand...

Just thinking ahead?
As we know, for example, the period following the summer shutdown was traditionally when motorcycle factories such as BSA, Triumph, etc. started building their 'new season' models-due to the length of time it took to ship large quantities of machines around the world so dealers had sufficient stock in readiness for start of the new sales season, so autumn should have been a reasonably busy time for Norton too, I would have thought?

Unless this Norton has a bitsa background I'd say that is a Mk2. If you look at the Mikuni mounting you'll see the backing plate of the "ham can" airbox, the Mk2A models had the same airbox as the Mk3's which must be removed to fit a Mikuni, leaving a rather large hole, exposing the battery.