Does anyone know the gear ratio on the 1942 M20 and if it is 2:1 will the few that are sold on Ebay work or does anyone know where I can find one or any sort of info would be helpful

email (option): bjsullivan23@ymail.com

These all look similar but 9 out of 10 are not suitable for a BSA M20 as most rotate the wrong way around. M20 speedo gearboxes are getting pretty hard to find.

Henk.

email (option): ahum@quicknet.nl

I just ebayed one, and it fetched more than a Bantam speedo i also sold. $150!! Remember that BSA C11's use a nearside speedo drive as well. You might have to buy a C11 to get the drive!

I have a G3 Matchless speedo drive in verry good condition it turns the wrigth way anti clock wise only the axle hole is smaller can i used it for a M20? For the rest is it exact the same. Gr Theo

email (option): oldbikes@kpnmail.nl

No, it would turn in the wrong direction.If someone sends me a knackered one i have a couple of reverse drive gears to fit in one.

Thanks there is a c10/11 speedo gear drive on eBay right now would that one work

email (option): bjsullivan23@ymail.com

Yes, but the axle hole maybe slightly bigger or smaller, but no big deal. The important part with any of these drives is you must have an inner spacer for the outside axle spacer to clamp against.

Hi Douglas,

On my 1940 WM20, i lost the worm/spindle of the speedo drive gearbox

Do you sell this piece?

I'm french

thanks
Marc.

email (option): letabli@gmail.com

Do you only need the small driven helical gear? The spare i have is worn but servicable if kept greased. Lots of people dont bother to grease because of the stupid early grease nipples. I'll send a picture here of the parts.

Sorry Marc, i got my two drives mixed up. It's the worn one on the left which is WM20 and too worn. the one on the right is servicable but it is the opposite drive.

Hi Douglas,

yes i just need the small driven helical gear,. It's a pity that it is no longer usable. thank you anyway.

Marc.

Would you know where I could buy a speedo drive to suit my M20?

email (option): ininness@outlook.com