Air slide and A/V levers - which and when?

Chris, in the absence of anyone who know what they're talking about, I'll have a stab.

Pre-war Nortons, most wartime production and it would seem the 1946 models were fitted with 'Doherty' controls with a rather sophisticated friction system involving a locking tab with an internal 'D' which meant that tension and adjustment were not reliant on the top cap staying tight.

These Dohertys were quite squared off and had the flat tab thumb push and a hexaxon cap retaining screw.

Examining period illustrations suggests that they changed to Amal controls for 1947 which would mean a spring washer internally but tensioned by the top cap hexagon screw. However, these early post war levers with a rounded knob had arms which showed quite a pronounced upward curve.

My perception is that those with a slotted screw are 1960s levers. A quick look at the 'Norton Twins Restoration' book shows a 1957 '88' with a short ball ended lever but still with a hexagon screw. The 1961 '99SS' illustrated has slotted screws. Later in the 1960s they appear to have gone over to recessed slotted screws. I'd suspect that your lever with a flat tab and a slotted screw is probably a later pattern part.

I'm not sure if Nortons used Bowden levers at all but they are usually recognisable from their use of a leather washer in a conical seat as a friction device.

I'd be most surprised if Bracebridge Street ever fitted odd levers to a machine. I can hear John Hudson denying the very possibility as I type !

This is the earlier Doherty model :-

[IMG]http://i248.photobucket.com/albums/gg164/commando16h/NOC/DohertyEarly.jpg[/IMG]

Rich

Doherty internal construction :-

[IMG]http://i248.photobucket.com/albums/gg164/commando16h/NOC/ARlever-dismantled.jpg[/IMG]

I like these levers a lot. Does anyone have any internal 'D' tab washers spare ?

Rich

Previously wrote:

Most of us are familiar with the handlbar levers used for the carburettor air slide and magneto advance/retard. These come in two main types apart from some earlier ones that were much longer and the ones unique to the Manx and 500T. I have attached a picture showing one of each type. The first has a ball end and the second has a flattened end.Does anyone know how these types relate to different Models of Norton, or more likely when they were fitted? Which came first? Did they overlap? Were both ever fitted to one set of handlebars?Discuss.

For what its worth.................

My 1950 model 7 has the type in the top of your picture ( ball end, hex nut on top, bent lever.

My '57 model 77 has the flat blade, slotted screw.

Skip Brolund