Chronometric Speedo, which one?

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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AndyO
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Location: Gloucestershire UK

Chronometric Speedo, which one?

Post by AndyO »

The Speedo on my 54 G80S starts from Zero bottom left and sweeps clockwise to 120 bottom right. Is this correct? Some bikes seem to have the upside down type.
Andy
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Mick D
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Re: Chronometric Speedo, which one?

Post by Mick D »

Hi

According to the Smith's list your bike would have been fitted with an S.443/1/L which is a 0 - 80 MPH version.

S.433/3/L is a 0 - 120 MPH equivalent - though rather ambitious for a G80S :)

Regards Mick
AndyO
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Joined: Mon Oct 26, 2020 5:24 pm
Location: Gloucestershire UK

Re: Chronometric Speedo, which one?

Post by AndyO »


This is the original Smiths catalogue. It says the 54 G80S was fitted with an S.433/1/L which is a 0-80 but on the back page it mentions an alternative model that could be fitted, S.433/3/L which is 0-120
I’m none the wiser! I’m not particularly bothered but my needle won’t return. Odometer and trip work ok. Stripped the chronometric movement out but can’t see the issue.
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clive
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Re: Chronometric Speedo, which one?

Post by clive »

The correct face for a 54 would have zero at top right and apparently would have an 80mph speedo fitted (433/1/L) according to the Smiths Catalogue however the 54 AMC parts list shows the G80S fitted with a 480/3/L which is a 120mph speedo. Either would normally have a teardrop type needle. Your speedo is from a slightly later machine but if you can get it working it should be ok. Its difficult to advise on the cause of the needle not returning but the odometer and trip work quite separately from the speed. If you are willing to take it apart you might look at the slipping clutch below the camshaft assembly, the hairspring on the balance weight, wear on the fork and spindle assembly, the four leaf spring and the hairsprings on the corrector and integrator wheels. http://archives.jampot.dk/technical/Spe ... _Views.pdf
clive
if it ain't broke don't fix
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clive
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Re: Chronometric Speedo, which one?

Post by clive »

Here is a 480/3/L i was just working on. Side trip so mounted on the fork crown not in the headlight shell.
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clive
if it ain't broke don't fix
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