The Vincent mechanism works very well with the Quaife gear set and camplate. I've yet to miss a shift with this setup and it can be shifted very fast, unlike the stock box.
John McDougall figured that the slow shifting/ bad shifting with the stock box was due to the camplate shape.
He modified the stock camplate to Norton/AMC shape. This worked well, the bike shifted fast and precisely, like a Norton does.
The very large number of parts that make up the Vincent selector mechanism does seem like an overcomplication, however it does all work nicely once the camplate shape is corrected.
On the other hand, the AMC box manages to do the exact same thing with a just a few cleverly designed components.
The compact little AMC box is a thing of beauty and mechanical simplicity. The original design of the box goes back to Sturmey Archer in the 1920s.
It was designed for bikes with perhaps 15 HP. With very little strengthening worked fine right up to 60 HP of the 850 Commando.
Glen
