OK if your using a Jaeger type speedo on a 1941 M20, you will need to inform Dave at JJ cables (tel 01926 651470) That it's the type with a square on the driven end of the inner cable as opposed to a spade end. Ron
Thanks again Ron for the valuable information, you’ve saved me no end of problems there, would this not have been the correct speedo for this year of manufacture? , I’m guessing they all would have been altered at some point depending on what parts were close to hand regards Neil
Yes I would think by 1940 the Jaeger pattern went out with the introduction of the left side mounted hub speedo drive. It should have no trip or illumination. You might well be able to do a deal/swap with someone on here. Ron
BSA seem to have received the first delivery of the new type Chronometrics with the screw fitting cable. The associated thin cables are visible as Ron says, as soon as the 'pancake' drive replaced the brakeplate type. The earliest bike that I have on file with this is C3928669 which was very early in contract C5110 which was delivered from September 1939. C3915154 from C3655 delivered June - September 1939 had the older type.
Norton didn't change until half way through C7353 which would be early 1941 so there is far more scope for fitting them to early Nortons.
I'm not sure that I can really see what's going on there..The boss looks too large and long for a Jaeger type. Is it a screw type with a stripped thread and someone has tried to make up an adapter to hold the cable (which seems to be too short) ?
I think it's going to take a closer higher resolution photo to understand.
The face with yellow line is as per the pre-war type, but I have an idea that it may have continued a little longer. They can be mixed and matched of course.
I've zoomed in as much as I can and can't see any resemblance of a thread on the boss. It has the earlier pointed bezel and as you say Rik, the yellow 30mph line. Neil can you take it, or the cable off when you can for a better picture of the back. My moneys on Jaeger type. Ron
Hi Ron, an update for you, I sent the speedo to Philip Woods for a new glass and a recondition, he confirmed to me that it requires a pin drive cable, , someone had fashioned an adapter for a square drive cable. He put me on to JJ Cables who I will contact shortly, hopefully I’ll get to the bike shortly and fit the parts , I’ll post my findings. Best regards Neil
Hi neil. Yes I posted contact details for Dave at JJ Cables in and earlier post. To save you phoning him about the length, this is how he will advice you:-
Mount the speedo and with a tailors tape, measure from the ends of the threads on both speedo and gearbox ie the outer cable length. Tell him that's how you measured it and he'll know the rest. Ron