Just to be clear, I am not a BMW taliban, nor am I a Vincent fundamentalist. But when I find crap designs I say so, and crap you find in ALL types of machinery. So from long experience with many types of bikes I can tell what works and what doesn´t - from gut feeling and drawing conclusions not maths . And I do not want to say this or that brand is great but try to draw benefits from all types to achieve reliable results. So when pointing to this BMW type ESA - or the Kawa 1300 version - I had reasons to do so. The Vincent ESA is crap - period - and some more details as well . No matter how you paint it, there is scope for improvements with a radical change as I have tried to explain - and am a bit puzzled that my views seem a bit hard to follow ?
Yes, with BMW or Kawa ESA there is some axial loads from springs acting at bearing inners and some wear as well, but nothing like with the Vincent miserable flat lobe shapes when only very heavy spring loads are meant to stop the twisting motion within the ESA. The BMW lobes rise to a steep gradient over 45 degrees so when remembering force vectors in school you may get the idea that most of the torque is contained in the lobes unlike in the flat Vincent ESA lobes , that turns all forces into extremely high axial loads via the sprocket onto the inner race of the outer bearing - with a lot of wear - and which you do not get in BMW gear boxes.
In Vibrac´s project , using a belt drive (?) I see a problem with durability like Vincent Speet said above: The twisting motions in the poly dampened design will produce either wear in the cylindrical sprocket fits or seizures when no oil lubrication due to belt drive there.
Seizure is no big problem in a chain/belt drive machine I think, no non-effective ESA so no problem. But wear will be bad for the drive and not easy to avoid without oil lube. So not yet a finished design.
Vic