bearing conversion kit?

Can anyone tell me a source for a Series1 commando frame neck bearing conversion kit?
That is where the discrete races and balls are replaced with 6205 2RS bearings and the correct length spacer tube.
I have a S1 frame here in the converted form, but don't know the source for it. I could always reverse engineer and make it myself, but sometimes I don't want to always take the hard way...
Saw nothing at AN, RGM or norvil.

Thanks
Would never have thought it would have been on the 7th and last page of " Primary Transmission" parts.
Will have to check my featherbed steering stems and frame neck to see the difference, if any, to the early commando besides the 26 VS 28tpi stem.
It is labeled as a "domi" conversion part.

dynodave said:

Thanks
Would never have thought it would have been on the 7th and last page of " Primary Transmission" parts.
Will have to check my featherbed steering stems and frame neck to see the difference, if any, to the early commando besides the 26 VS 28tpi stem.

Click to expand...

Might be good to let them know those parts are in the wrong section. They have the later Commando one there too.

AN now also do a kit i seem to recall
Happy Holiday guys

olympus said:

AN now also do a kit i seem to recall

Click to expand...

https://andover-norton.co.uk/en/shop-details/20867

The RGM tube would need to be length reduced in the lathe to fit a Commando.

Its only a couple of bearings and a easy made tube.
Even the stock set up if my 71 was anything to go by meant the lower bearing needed to be seated and with heavy disc's (Isolastic caps will work) the upper pulled in to seat on the spacer tube without loading the bearing centres/centers.
The top bearing would not be seated in the frame and from the factory it seems.

Took one bearing out of my friends S1 frame.
Tube is 25mm ID x 35mm OD x 134mm long precision stainless.
So, as I suspected, slimline and S1 commando front end neck are basically the same except all UN threads.

dynodave said:

Took one bearing out of my friends S1 frame.
Tube is 25mm ID x 35mm OD x 134mm long precision stainless.
So, as I suspected, slimline and S1 commando front end neck are basically the same except all UN threads.

Click to expand...

Someone made a tube if it is stainless but I don't know about the early Commando frames if that is what a S1 is, the bearing seat measurement must be very different from the later bikes.

You measured between the steering head bearing seats also ?, it would be interesting to know if there was a change in the steering head to the later frame.

Here are the spacer tubes out of my 1971 750 and 1974 Mk2a and neither are anywhere near 134 mm but both exactly the same length.

Time Warp said:

1971 750 and 1974 Mk2a

Click to expand...

Both of your rolling chassis I call S2 the tubes should be 129mm

S1 spacers are 134mm long, slimline should be the same

https://www.accessnorton.com/NortonCommando/versions-of-commando.27393/
S1 S2A.1 S2A S2B S2B-E are all the variants of commando rolling chassis.

20M3, 20M3S, 200000, 300000, 325000 are all the main variants of production commando engines

or this to make things really clear?...really? LOL

750cc
Original Commando 4/68-3/69
750 R 3/69-9/69
750S 3/69-6/70
Fastback 3/69-8/70
Fastback II 9/70-12/70
Fastback III 1/71-12/71
Fastback IV 1/72-3/73
Fastback LR (Long Range) 4/71-12/71
Fastback LR MkIV 1/72-2/73
Roadster 3/70-12/70
Roadster II 1/71-12/71
(no MkIII Roadster, apparently!)
Roadster IV 1/72-2/73
Roadster V 3/73-10/73
SS (Street Scrambler) 3/71-10/71
PR (Production Racer) 4/71-10/73
Hi-Rider 5/71-12/71
Hi-Rider IV 1/72-2/73
Hi-Rider V 3/73-10/73
Interstate 1/72-2/73
Interstate V 3/73-10/73
850cc
Roadster 1 3/73-12/73
Roadster 1A 9/73-2/74
Roadster 2/2A 1/74-2/75
Roadster 3 2/75-9/77
Interstate 1 3/73-12/73
Interstate 1A 9/73-2/74
Interstate 2/2A 1/74-2/75
Interstate 3 2/75-9/77
Hi-Rider 1 3/73-12/73
Hi-Rider 2 1/74-2/75
Hi-Rider 3 3/75-?
John Player Replica 11/73-2/75