1973 Norton Commando 850

NortonNewbie said:

I suppose what I have here then is a 1973 norton commando roadster frame with interstate tank, while the engine could be either interstate or roadster?

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Its perhaps worth repeating that the engine is IDENTICAL for all Roadsters and Interstates,
they all came down the same production line.
And then just had suitable tanks seats sidecovers handlebars and exhausts added to make them whichever model.

The frames for Roadsters and Interstates were also all identical, and all came from the same parts bin.
Side by side, there is nothing different about them - again they added whichever bits to make them each model.

That is quite a good looking bike - nice find.

While it can be debated whether the bike originally came with different frame number and engine number, there are a couple of other considerations.

What number is on the title? Engine number? Frame number?

Would you be titling the bike in the same state as it is currently titled? Out of state purchases usually require a serial number/VIN verification. This could cause some issues at the title bureau. Also if the bike is titled by the frame number, you would definitely NOT want to restamp a new frame tag with the engine number.

Does the gearbox number match one or the other?

I see the bike has had the front fender replaced with a Mk III one, so it possibly could have had some damage at one time. Could be the frame was replaced at some time with a used one. I would look closely at the rear loop for signs of weld. It is not unusual for this loop to be damaged in an accident and is fairly simple to replace. This could explain the wide loop.

The number issue, original or not, can cause some issues with a resale. More so if sold in a different state. Of course it in no way affects the quality of the motorcycle or the enjoyment factor. One of my favorite things about Commandos is that there is a good market for modified machines. They don't need to be (nor can they be) documented to exactly the way they came from the factory. In fact, many modifications make them more appealing.

Just my $0.02.

Ron L said:

I see the bike has had the front fender replaced with a Mk III one, so it possibly could have had some damage at one time. Could be the frame was replaced at some time with a used one. I would look closely at the rear loop for signs of weld. It is not unusual for this loop to be damaged in an accident and is fairly simple to replace. This could explain the wide loop.

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Thanks Ron, all great things to consider, I appreciate the advice. I will definitely ask the seller if he knows why the front fender was replaced. Regarding the rear loop, did the 73 commando 850 have a wide or narrow loop? From what I have read I gather it is the wide loop, but please educate me if this is not the case.

I'm going by what I found here http://atlanticgreen.com/commandoframes.htm

I use the same seat on my Interstate and love it.