Author Topic: STURMEY ARCHER GEARBOX INTERNALS  (Read 151 times)

Offline teapot

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STURMEY ARCHER GEARBOX INTERNALS
« on: October 08, 2019, 12:10:57 PM »
Hi
Can any Norton/AMC gearbox internals be used in Sturmey Archer LS type gearboxes if the bearing sizes are changed to suit. I believe that the Norton box was developed from the Sturmey box and the design of the gears/ dogs etc. look very similar.
Regards Richard.

Offline R

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Re: STURMEY ARCHER GEARBOX INTERNALS
« Reply #1 on: October 08, 2019, 10:48:16 PM »
This may possibly be one of the most obscure and obfuscated subjects in motorcycling ?
There must be many folks who have rebuilt these and are familiar with the varieties and complexities,
but finding solid details in writing seems near impossible.
Further input very welcome ...

P.S. So, what is a SA LS gearbox.
A 3 speed ?
http://www.mattsb.com/gearbox/images/Sturmey_Archer_mod_III_14_JPG.jpg

The NOC website has a chart of gear numbers, for both SA and the "Norton" branded 4 speed box that replaced it.
Without stipulating any interchangeability - you sometimes see that "some gears are interchangeable"

Offline 33d6

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Re: STURMEY ARCHER GEARBOX INTERNALS
« Reply #2 on: October 08, 2019, 11:04:58 PM »
Some times yes but the nonsense you go through to check it all out doesnít make it worthwhile. Itís easier to just make new.
Sturmey Archer did so many minor variations for various manufacturers it is much easier just to remake whatever variant you have than faffing about kidding yourself you will find a usable Norton part.

Offline john.k

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Re: STURMEY ARCHER GEARBOX INTERNALS
« Reply #3 on: October 08, 2019, 11:42:21 PM »
There is not one piece in a LS box similar to a AMC box........however ,if you go forward about 5 years,the Four speed Sturmey Archer box is the forerunner of the AMC box,and there is some interchangeability .....and the Norton dollhead box made by Burmans has about 80% of interchangeable parts..........In the various owners clubs ,parts runs of LS parts have been made,at considerable cost.

Offline john.k

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Re: STURMEY ARCHER GEARBOX INTERNALS
« Reply #4 on: October 08, 2019, 11:45:46 PM »
However ,there is great similarity in the kickstart mechanism,and some of the bits ,like the sprag,pin,bushes maybe,and the external spring......worth comparing,if you need kickstart parts.