Velocette Tach Drive Replacement

My Velocette is a 1959 MSS, that has the full “Venom/Thruxton” treatment. I put that it quotes, because it has the Triumph TLS front brake instead of the Velo TLS, and it uses an Amal Mk3 carb, which means that it starts and idles wonderfully.

I purchased it that way from a nice man near Sacramento, and it had only one issue — the tach drive was a 1:1, and the tachometer attached to the bike needed a 2:1. I needed to get it fixed, and I’ve put it off for quite awhile. The current coronavirus lockdown has provided me opportunity. I found a tach drive and now it’s time to install:

So I get the bike on the lift, and unhook the drive cable. Of course the spade in the cable fell out on the lift table, so I put a dollop of marine grease on it and re-installed it.

Then I removed the drive by unscrewing the fixing screws. It came out with the pilot shaft that fits into the driving spade deep within the crank case. When/if you have to do this bit, be sure that when you remove it there you are taking care not to drop it in as this could possibly happen. When you have it all apart, it looks like this:

Ready for new tach drive

To re-install, first attach the pilot shaft – use a little marine grease to stick it safely to the spade in your drive, and line it up with the engine’s drive spade. Insert a screw so you line the holes up as you’re getting it ready to offer up. Once it’s in, screw it down tight, then attach the drive cable.

Finished!

Finished!