Simple Solution

At the warehouse open house, one of the cars in the aisle was a licensed sports racer looking car with a bike engine. The owner called it "Piontek" and said that this was the latest built and number 6. A beautiful car with lots of interesting ideas, the one that struck me as a clean and simple solution was its reverse drive.

Lots of bike engine cars use a starter motor as an electric drive reverse gear. In this case, he simply had starter gear teeth cut into the outside of his inboard rear brake disc. Add a couple of brackets for the starter motor and you have an elegant solution to reverse gear in a bike engine car.