Bob,
we had a discussion a while ago about the ESA, see link below. There are more details there and am afraid some did not get the point I was trying to make clear - instead trying to find excuses and making believe that the BMW type would not work on a Vincent. But they never found a real argument why it should not. BMW has sold millions of Bikes up to 1000 twins with that ESA in the gear box, and with a lot smaller size so the torque and loads are a lot higher than with the bigger Vincent parts - which has three lobes instead of just two in the BMW. To this day I have not seen a good photo of the current spares so must assume the design has remained basically and it cannot be modified to really do its job, no progressive action in there.
I am happy to send the alu test set to examine, the male side is simple to machine on any CNC plus dividing head. The female side requires a motorized dividing head with encoder for fast and smooth machining - any Mach 3 stepper motor CNC mills could do it but you had to pick a solid machine for milling that. I say any competent CAD and CNC guy should be able when I did it by pocket calculator and manual mill plus DRO on the mill and encoder on the dividing head - slowly but perfect from first try and two sets of ESAs welded and milled. I cannot provide a drawing, not easy with 3 D dimensions. But I can point to the logic how to find the data. We can go into details in PMs but for getting things done a public discussion may lead to results sooner than contacting the inner circle where all efforts may be dumped .
I do know Tim has redesigned the ESA shapes a bit and I am quite aware he will not be amused. But a working new design may produce a big sale and income to the club to compensate for remaining stock that will only be used for replacing some defect parts then.
There are some more photos of this type of ESA, some from modern BMWs , one in the Kawasaki 1300 four, so they really know . . . .
Vic
ESA new design
Kawasaki 1300 , one, maybe two ESA inside gearbox:
BMW R100 gearbox input :