Hi ian. I have some experience of industrial mechanical power transmission from a previous life, but we never did any roller chain drives. However, a few things to ponder. The front sprocket , although the teeth feel the same force as the rear sprocket, they are subjected to it more often for obvious reasons. I've always understood the main cause of tooth hooking is stretched chain. The reason being that a stretched chain is longer between each centre and so adopts a position further out on a greater pitch circle. I'm sure lubrication obviously play an enormous part, as does material quality.
One theoretical way to reduce the force going though the chain and the pressure on the tooth is to increase teeth numbers on both sprockets. The penalty is higher circumferencial speed, though this is hardly a problem on an Enfield! The main restriction is the lack of clearance around the gearbox area (on all bikes, not just a mighty enfield)
None of this really helps! 😄
