TOPIC: Commando Rolling chassis

ROLLING CHASSIS SERIES 1- 27 degree 750

I've been doing an amount of cross year component compatibility across the whole norton heavy twin family.
Had to categorize frames as different "rolling chassis" types.
For example:
Garden Gate plunger or swing arm
OR
Featherbed rolling chassis BUT identified as wideline or slimline
AND
Last there is Commando, which means an isolastic mounted power plant carried within the frame structure. It is interesting to note that a basic Commando configuration yielded about 34 identifiable models. This is in an incredibly short period of time during which Norton Motorcycles was in it's corporate death spiral ending in 1975.
Please note that Norton did NOT follow typical american MY (model year) start and stops dates.
This often leads to identification confusion if a model year(MY) is implied..

COMMANDO Rolling Chassis SERIES 1 (750cc)
Original Commando 4/68-3/69 prior to being named "fastback"
Fastback 3/69-8/70
"R" 3/69-9/69
"S" 3/69-6/70
Roadster 3/70-12/70
Fastback II 9/70-12/70
END Series 1

Now to identify the above listed ROLLING CHASSIS variants:characteristics.
Generally 68-69-70 commando would be identified as Series 1. What characterizes them as S-1?
First is the type of front steering configuration. The S1 is directly carried over from the slimline featherbed.These variations are shown separately at the bottom of this topic
1. The bearing pockets are at the very ends of the neck tubing.
2. There are two steering stop tabs again carried over from the featherbed. They are however implemented in a different fashion as welded on tabs situated on the front of the neck to hit the rear of the triple tree front cross bar. .
3.The steering lock tab is very small and situated on the top RH side.


4. The lower frame cross bar Is situated to the rear below the gearbox. It also mounts the center stand to the rigid frame.
5 The side stand mounting tab is mounted on the LH frame rail forward of the cross bar.


6 Triple tree fork leg offset is 2-1/4"

7. The very earliest frames were "widow maker" and lacked the secondary cross bar behind the steering neck. Here is the inadequate short little gusset. The first commando issue had no VIN plate. Note there is no vin/cert plate on this early frame yet...


8. That was later followed with the Norton Villers LTD "LONDON, SE18, ENGLAND" Certification plate 06-1286 These are Woolwich manufactured nortons. This VIN/cert tag is on all later and only series ! bikes.


For a couple of years, work at the AMC factory was limited to the production of the few remaining Matchless models and the new Norton Commando, the engines and gearboxes for which were shipped down from Wolverhampton.
Then, in late 1968 the Plumstead works at Burrage Grove, were presented with a Greater London Council compulsory purchase order for a major road widening scheme, finally closing in July 1969, with the land that it occupied given over to housing development.

9. They had two mount pins on right rear frame to mount a bicycle type air pump.

Rolling Chassis SERIES 2A = 27degree/750
Roadster II 1/71-12/71
Fastback III 1/71-12/71'
SS (Street Scrambler) 3/71-10/71
Fastback LR (Long Range) 4/71-12/71
PR (Production Racer) 4/71-10/73
Hi-Rider 5/71-12/71
Fastback LR MkIV 1/72-2/73
Fastback IV 1/72-3/73
(no MkIII Roadster)
Roadster IV 1/72-2/73
Roadster V 3/73-10/73
Hi-Rider IV 1/72-2/73
Interstate 1/72-2/73
Interstate V 3/73-10/73
Hi-Rider V 3/73-10/73
End Series 2A

Starting around December of 1970 Norton changed the design significantly and I designate them as series 2 or S2.
1. The steering neck was 27 degree for 750's.carried over from featherbeds. but the triple trees were made with more offset and the style was different. This also caused the bottom bearing to be moved higher up the steering neck in a deeper pocket. This reduced the bearing to bearing spacer dimension. SEE yokes/tripple tree below

2. Series 2 no longer has the bicycle type air pump mount.
3. The S2 frame lower crossbar was forward mounted and the side stand mount was closely integrated. however:
4.The first product issue was S2A-1 for 1971.This one year version was an engineering mistake of the side stand mount. It was a welded on "pin"that was weak and broke easily and would also shed the circlip that retained the side stand allowing it to fall off. These S2A-1 use only the 20M3S engines.These frames are often upgraded to the regular S2B side stand mount as seen below. .


5. The MY 72-73 S2A side stand changed to a welded on upgraded thick plate assembly with a grade 8 through bolt to hold on the much improved side stand. see below
6. Typical date stamp on LH lower Z plate gusset mount "R"(renolds)+ numeric month and 2 digit numeric year.



7. The ANDOVER ENGLAND VIN tag for series 2A is as follows both S2A-1 and 200000 only until the end of the 1971 calender year. So S2A as high as 202200 combat series were still using this early tag 06-1441 until the end of December 1971.


8. Starting in January of 72, the whole remaining 200000 and 300000 Series, stopping at 325000(electric start), used 06-3247 GVWR 859 cert plates as shown below..NOTE: initially 200000 series stamped with 3 letter/month and 4 digits/ year. When changed over to 2 digit month and 2 digit year has yet to be assertained?
Please note most repop cert plates are incorrect. "The date of manufacture shown above" should be ALL on one line such as seen below on an original VIN/cert plate.

Rolling Chassis Series 2B (850cc)
Roadster 1 3/73-12/73
Interstate 1 3/73-12/73
Hi-Rider 1 3/73-12/73
Roadster 1A 9/73-2/74
Interstate 1A 9/73-2/74
John Player Replica 11/73-2/75
Roadster 2/2A 1/74-2/75
Interstate 2/2A 1/74-2/75
Hi-Rider 2 1/74-2/75
End Series2B

Very few changes from earlier frames
In early 73 The metric/italian frames were introduced being interspersed with imperial tube british frames. Rear frame loop reinforcements were also introduced

Rolling Chassis Series 2B-E (electric start)
Roadster 3 2/75-9/77
Interstate 3 2/75-9/77
Hi-Rider 3 3/75-?
End Commando

06-6213 - PLATE, FRAME IDENT, MK3, USA/CANADA


S2.B-ES new items
1. new style fork locking bracket on neck and different style lock,
2. Non adjustable fixed G-box locating top thru bolt holes on engine cradle..
3. seat hinge fixing and lock,
4. new style MKIII cush drive rear hub and swing arm all to accommodate the vastly different electric start 828cc drive train.
5 new top triple tree for mounting switch and light cluster dash board
6 Totally new wiring harness first 2000 with old style WL3 asimilator.
after initial style the new solid state assimilator except for canadian "light on" warning module
7. Totally new drive train

The fork legs and brakes can be upgraded or changed, but the triple tree type needs to remain as a set with the frame to be compatible.


Left end black is 7-3/8 C-C featherbed slimline triple trees handle bar clamp allens are 5/16 BSF threads and stem is 13/16 x 26tpi.
This exact featherbed style for the first command are identical castings except 5/16 unf allen screws for the bar clamps and 13/16 x28 tpi stem threads, These have delicate threads and components are often made poorly. For this reason I have had to buy taps and dies for both 13/16-26 and 13/16-28 to clean up damaged or poorly made threaded stems and retaining nuts.

2nd from the left the top triple tree has added bosses underneath for screw mounting the later halo head light frame assembly. In addition the lower TT has a longer clamping stud with 1/4-28tpi threads to attach the lower halo framework.("S" and Roadster).

In the center, the two tubes show the different lengths of the bearing pocket bores in the S1 vs S2 frame necks. This difference makes the S1 and S2 frame/front triple tree parts NOT interchangeable.
The center TT are for 27 degree rake S2A 750 frames.
4th from left is normal 28 degree rake for S2B 850s 73-74
RH TT is for the 1975 S2BE top TT and has the basic 28 degree neck but IN ADDITION the 2 hole mount for the key/lite panel.
Both the featherbed and commando stem and nuts are very easy to damage if mixed up. I have had to buy both 13/16x26 and 13/16x28 both taps and expandable dies to "clean the threads". New replacements don't always have good tolerances and fettleing is need to make them good..