Commando frame number

Hi Ross ,  according to Roy Bacon in his book Norton twin restoration ,If your frame  number is 321721, it falls between January 1974 (307311)  and february  1975(325001) .   hope this helps .

3217123 is not a Norton number ( One too many digits and the stamps look modern format), for the Fastback the number was never stamped directly to the frame but only on the red plate. What is the number on the red plate.

1. The early 68 commando (before they were named  fastback", and before there was a 06-1286 LONDON "red VIN/SN plate. Most had a # on the LH side of the neck.

2. Is there a part# on the front of the LH tank mount ?

3 Is there a date stamp on the LH gusset behind the Z-plate?

4 is the lower frame cross bar rear or forward mounted?

5. Are the small frame tubes 25mm or 1"

Work in progress but pix alway help:

https://nneno.org/forum/norton-rolling-chassis/627-commando-rolling-chassis-family

https://nneno.org/forum/norton-rolling-chassis/627-commando-rolling-chassis-family

Hi Ross,

Your frame appears to be a replacement, it should have one with a head stock as shown in the

attached picture. A lot of the early original frames where replaced as they broke, detailed in the link

below.

What is your engine and gearbox number? The frame number makes it 1968.

Best wishes,

Terry.

http://www.workingatamc.london/testing_commando_frame.html

In the headstock or on the main tube under the seat… if it’s not a replacement.

J

Later series 1 bikes have two tabs on the headstock to limit front end rotation. I have now verified the earlier frames have a welded on plate such as the last atlas' to restrict rotation ? Evidence is seen on the pix above.

Also what is the location and specific nature of the "under seat" vin stamping?

Curious to discover after the end of the widowmaker frames, approximately when did the VIN/SN cert plates start?

TIA

… was referring to the four holes used to secure the VIN plate on the headstock or under the seat for the JPN and one other model as I remember…

 interesting link on your previous Dave,  thanks.

Cheers

Jon

Jon -thanks for clarification.  JPN are so scarce here and rarely seen as a common commando.  I was aware of their uniqueness. The unmodified early S1 bikes are rare as to vin stamping and VIN plate attachment. The beginning of the 06-1286 cert plate utilization is still an unknown for me.

The NNENO site is around 15 years old but has evolved into a forum and finally reverted to it's original Northern New England Norton Owners use. NNENO started early 80's as a race team and evolved into a local club in the later 80's. It's open to join for those interested. It is for mostly NHT as pre commando, featherbed and gardengate since singles are quite rare here in the US.

Regardless of bearing type you will still need one of the two types of steering limiter.

Bearings can be cup and cone, the early ball bearing , very limited use, and very expensive early S1 bearing :

https://nneno.org/forum/norton-rolling-chassis/608-new-bearing-what-will-they-think-of-next

Or the regular 6205 ball bearing

Highly recommend the long spacer thrust tube to fit the early triple trees. Even for tapered roller bearings. Remember the S1 frames use long stem triple trees in "slimline style" but with all UN threads not British...though they can be made to work.