Phillip, it will have been a "Jaeger Type" speedo, with the thick cable, that fastens to the speedo with a screw, has an orange stripe at the 30mph mark, or in your case 50kmh. If it is a civillian bike, it can have a trip feature, military, always non trip, exept some Matchless contracts.
The sizes are all the same for the Smiths speedo's, whatever you do, NEVER buy a replica from India!
Here some pictures, the tag on the back will tell you the year, till 1940 they were aluminium, after that brass.
Whatever you'll find, It will be expensive!
Cheers,
Lex
email (option): welbike@welbike.net
Lex is spot-on, as usual.
You're not going to find a kilometer speedo in the UK (which is of course where most of the chronometrics are to be found) but the basic isntruments can be converted.
My impression is that civilian Nortons were fitted with trip speedos (the military despatch documents state specifically 'non-trip' which they wouldn't have done if that had been normal).
80 mph was normal for UK market 16Hs so I'd expect 120 kph for Europe.
If you find a later type, the thick Jaeger cable can be more or less faked with a rubber tube over a modern cable.
I'd be inclined to talk to someone like David Woods. He doesn't normally sell speedos outright but could advise you on what he might be able to convert which would give you more options in looking for a donor instrument.
http://www.chronometricspeedos.co.uk/
Something like this maybe? The ammeter is a CZ23 but I have no idea of what years they were fitted. This speedo has the clamp on cable and no light.
email (option): rbrouard@guernsey.net
Hi Lex, hope to get you back here again one day.
I was wondering about the date on these items, maybe you can confirm.
Best Regards
Rick
email (option): rbrouard@guernsey.net