Found a new 2/1 speedo drive, marked BG5330/247, and painted light grey; is that a correct one for the WDM20?
Hans

email (option): viaconsu # planet dot nl

Hi Hans,

Mine is directly off a WDM20 - it is marked 'Brit. Pat. 529397 on the front. And on the cap of the worm drive it is stamped 52283.

Couldnt find any other numbers...dont know if this helps....

email (option): adh325@hotmail.com

Don't forget it must turn in the right direction when fitted, as they have a reverse drive for nearside fitting.

Hm, I think I have a problem....
The drive 'cigar' (how do you call this in the Queen's English?) should be in front of the front wheel axle, but with this one it will be behind the axle. Do those numebers mean anything? And for what bike could it have been?





Can the connection be reversed: threaded end with the end cap? When done, the drive square will turn anti-clockwise.
Any help appreciated!

email (option): viaconsu # planet dot nl

That is a pattern drive for the 'modern' Smiths units, such as fitted during the 1960s / 70s. It's probably intended for rear wheel fitment on the timing side.

I'm not sure what the 2:1 fits. It's not Norton Commando though.

The end cap and cable boss can pop out of their own accord and it isn't possible to then satisfactorily re-fit them so I don't think that you'll have any luck swapping them over.

The consequences of the speedo drive worm locking up are such that I wouldn't recommend bodging one fitted to the front wheel to anyone who still has their own front teeth !

The internals are different. I have a proper spare one but it's going to be my retirement fund.And it would cost a fortune to post O.S anyway.

I'm already bidding! ...Ian