Geez, I didn't know the "Ballbearing lower link's" were available...........
Mine's a long way off fitting a quad ring.
But for info, I did fit a well-greased O-Ring to the Series A, a while ago, with a tiny bit of compression. It split while moving the bike around in the garage! It seems they're not designed for that kind of shear load.
Just saying.
Peter B
I thought that would also happen with nitrile cord superglued together, but I think Norman''s rings will be stronger. I think home made o rings will only work under static compression. Bring in movement and it is a different ball game.