Pretty cool. I think that must have been one of the early Pro Battle of the twins racing when it was just getting started in the early 80's.That is when they were runningBeemers and Guzzi's. That is the chain drive XV920RJ, I think. They are getting real hard to find and are expensive when they are found. I would love to find a rough version of one of them instead of considering trying to convert a shaft drive version to chain.