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Commando Wheel Offset

posted 25 Dec 2011, 04:40 by NOC NSW   [ updated 25 Dec 2011, 04:44 ]

Question sent into NOCNSW

I have just purchased a 1973 850 commando interstate. it came with re-spoked rims out of the bike, when fitted the offset lookes wrong, about 9mm to the left, sitting on bike. Can you tell me the offset for the wheels and who is the best for spareparts and tank re-spray?

Answer from Geoff

The engine, engine/gearbox plates, gearbox, swing arm and rear wheel hub are offset about 1/8” to 3/16" to the left. The rear wheel rim should be laced with an offset of the same to the right to bring it back onto the centerline of the bike.
The front and rear rims should end up on the centerline of the frame. The spokes beside the front disc should be nearly vertical.

You can see some actual offset measurements here:
http://www.kolumbus.fi/norton/norton/frontalign.jpg
http://www.kolumbus.fi/norton/norton/rearalign.jpg

From the UK Norton Website:

Commando wheel offset - the definitive answer
I have the definitive answer as to what is offset, how much, and which way! 
I set up a 1973 850 on the frame table and verified it was straight. I then put together a dummy engine and installed it with new isolastics, new washers, Hemmings adjusters, and a Norvil head steady. I put both adjusters on the left side, checked the swinging arm in my fixture and then installed it in the frame. I took all the play out of the adjusters and started measuring:- 
The frame is symmetrical 
The engine/gearbox cradle is offset 1/8" to the left. 
The swinging arm is offset 1/8" to the right so the axle pads end up centred in the frame 
I then installed the rear wheel:- 
The spoke flanges are offset 1/8" to the left as mounted in the arm, so the rim is laced off 1/8" to the right to put the tyre in the centre 
The centre of the rim is 3.3/8" from a straight edge laid across the brake drum (not the backing plate 
http://www.nortonownersclub.org/technical/commando/offset_detail.html


As for spare parts, Eades (9798 7822) are the only shop left in Sydney. They are reducing their opening hours, however they do mail order.
You may find Ryans (6558 8195) up at Gloucester a bit cheaper. They are mail order only but provide good service.
There is also British Spares in New Zealand (+64 4 939 8819) who are very competitive price-wise and also give good service. http://www.britishspares.com/

Painting:
The Keed brothers in Arncliffe are renowned for their good jobs, but they take a long time and are a bit expensive.
Ph no. 9567 5422 address: 54 Lower Wilson Rd Arncliffe.

Regards,
Geoff

Note: since this article was written Eades is under new management and is now Eade Classic Allparts and Ryans has ceased trading - NOCNSW Web Editor