Gearbox names

Previously ian_soady wrote:

All have similar internals. Upright were the earlier style and came in several flavours - the earlier ones have a bulge at the top which apparently looks like a doll's head to some. Later versions had a smooth oval outer cover, with a couple of small variations of clutch actuator access.

These boxes had an external linkage with clevis pins which was very prone to wear, and the top mounting was a slotted affair that fitted over a lug on the downtube. If this wore (as it did due to not being tightened up properly) then the "ears" broke off....

The laydown box solved these problems, having a solid top mounting between 2 engine plates and an internal linkage. Oddly, the competition models retained the upright boxes till the Featherbed came along.

As a matter of interest, the internals were very similar for the so-called AMC box that survived till the latest Commando.

Thank you for this Ian.

My ES2 - 1961 - has a box the same (similar to) my Dominator 99 and my Commando.

I assume these are all laydown boxes. Is this the same as the AMC box?

Previously Dan Field wrote:

Richard

I expect all of yours are AMC boxes, the laydown boxes were in the pre featherbed singles and look, well, they look like they are laying down! I'll see if I can find a pic.

Thank you for this Dan.

As you say, all of mine are the AMC box (although a laydown (I think) box was part of a 19S box of parts I bought.

However, the box fitted to the !961 ES2 has a square kickstart shank.

Although I haven't opened the box yet, it is certainly going to need some spare parts - bearings, spring etc.

It can just be seen by enlarging the attached photo.

Have you come across this square shank before?

Thank you all for the information.

Richard