differences between Commando and S type

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Lorenzo

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dear All,
I just got a Commando year 1971 with lower pipes, but I am not sure if it was formerly an 'S' type.
Apart from the higher pipes, can you tell the small and big differences?
Is there a difference also in the frame numbers?
Thank you for helping!
 
The last 'S' type is supposed to have been 135088 manufactured approximately June 1970.
What is it that leads you to believe your 1971 model could possibly have been an 'S' type?
 
L.A.B. said:
The last 'S' type is supposed to have been 135088 manufactured approximately June 1970.
What is it that leads you to believe your 1971 model could possibly have been an 'S' type?
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It could have easily been registered as a 1971.
 
L.A.B. said:
It could, and why we need more information.
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yes: it could easily been imported to Italy and sold later.. then for whatever reasons of the former owners been switched to a 'normal' low pipes norton commando..
anyone can tell how to spot a real 'S'?
 
Lorenzo said:
yes: it could easily been imported to Italy and sold later.. then for whatever reasons of the former owners been switched to a 'normal' low pipes norton commando..
anyone can tell how to spot a real 'S'?
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First post the serial number and then the build date (both on the "VIN" plate). That will at least verify if it's in the range of an S.
 
Serial number (leave the last two digits blank if you like)?

Does it have a central oil tank, RH battery access panel, steering stem attached to the lower yoke, adjustable bearings and headlamp halo, however, the 1970 Roadster also had these items?
 
Last 'S' model was S/N 135088 (allegedly). 1971 frame has centerstand attached to the engine cradle and sidestand is attached to a pin welded to the the frame. 1970 frame has centerstand attached to the main frame and the sidestand is short and bolts to a plate welded to the frame rail.
 
Ron L said:
Last 'S' model was S/N 135088 (allegedly). 1971 frame has centerstand attached to the engine cradle and sidestand is attached to a pin welded to the the frame. 1970 frame has centerstand attached to the main frame and the sidestand is short and bolts to a plate welded to the frame rail.
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I think I was wrong: it is definitely a 1970 bike, but not sure if a 'S'..
 
Ron L said:
Last 'S' model was S/N 135088 (allegedly). 1971 frame has centerstand attached to the engine cradle and sidestand is attached to a pin welded to the the frame. 1970 frame has centerstand attached to the main frame and the sidestand is short and bolts to a plate welded to the frame rail.
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my bike is 137XXX vin number..
 
Mine also has a 137XXX Number, dispatched in May 1970 to Gus Kuhn as a black Roadster.
I converted it into a Fireflake Blue S Type.
Go and ask Joe Seifert of NortonMotors, he can help you with the dispatch record maybe colour and type also to which dealer it was delivered.
 
Lorenzo said:
dear All,
I just got a Commando year 1971 with lower pipes, but I am not sure if it was formerly an 'S' type.
Apart from the higher pipes, can you tell the small and big differences?
Is there a difference also in the frame numbers?
Thank you for helping!
Click to expand...


Do you have the original sidecovers? Some, if not all of the the 1970 Roadster models will say "Roadster" on the sidecovers, while some if not all of the S models will say "S," or something like that.


You could also study/compare the hardware used for the rear mounting points of the pipes; there may be some differences from original depending on when the conversion was done.



.
 
Lorenzo,
Pay attention to what has been said. Central oil tank? Early forks with the 'halo headlamp ring mount'? Center stand on the frame, not the trans cradle? Side stand short and mounted with a pin off a bracket from the frame? Does the frame have a brace that nearly blocks the large sump drain? Does the rear mudguard have a indent for the air pump mounted on the rear frame loop? Two position ignition switch in left side panel, only on/off. All these things are possible indications of an original S type, but not for certain and plenty of modifications could be done.

There were also later Roadsters made and R types as well that still had these things. You have a pretty late serial number and I would doubt if it was originally an S type, but that doesn't mean you can't make one. The 137xxx is well past the alleged 135088 'last S' number.
 
DogT said:
There were also later Roadsters made and R types as well that still had these things.
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Roadsters, yes, as the 1970 Roaster was basically an 'S' with a low level exhaust system, but not the 'R' type which although having a similar fuel tank and seat to an 'S' was closer in specification to the Fastback but without the Fastback's tail piece and no 'S' central oil tank, RH battery access panel, headlamp halo, etc.
 
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As has already been said, the first Roadsters were just an 'S' with low pipes and different side panel decals. I think some of the new colours were also introduced around this time, but can't be certain (Fireflake Purple, Golden Bronze, Emerald Green etc.).
I have 13501X which the dispatch record shows left the factory as a green 'S' in May 1970. I'm assuming it's Fireflake Emerald Green (tank & panels long gone when I got hold of it), and not the plain 'British Racing Green' or whatever it's actually called as seen on early Fastbacks.

As I've found out, the dispatch records show quite a lot of overlap and out-of-sequence builds, with some 200 series bikes leaving the factory earlier than 135 series bikes.
Worth noting that the early Roadster pipes were tucked in at the head, similar to Production Racer pipes, and quite different to the later pipes which splay out more. Don't know if they are the same as the PR?
Norton Service Bulletin recommends broken 'S' pipes should be replaced with Roaster type, so it seems there were rather a few 'S' pipes failing in use and Norton just gave up on them.
 
B+Bogus said:
Norton Service Bulletin recommends broken 'S' pipes should be replaced with Roaster type, so it seems there were rather a few 'S' pipes failing in use and Norton just gave up on them.
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Do you have a reference for that Norton Service Release?

There was a Service Release for the 750 SS model (N.73, Jan. 72).
 
L.A.B. said:
Do you have a reference for that Norton Service Release?

There was a Service Release for the 750 SS model (N.73, Jan. 72).
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It's the only one I can find too: I recall some reference being made to 'S' exhausts but...?
I note Service release N8 refers to Roadster exhaust part numbers but I can't locate a copy :(
 
The S type exhaust system is a nightmare and doesn't last long. I think I had lost the heat shields by 4000 miles and one of the headers cracked soon after that. The dogleg bracket is a weak point also. But they are different and you can count on burning your leg at some point. That's probably why they recommended going to the Roadster type. I though about it at one point but I never had enough money to buy them.
 
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