Are you able to tell me why they used to use a fluted and flat pair of blades on the early rideons? What was the purpose? Also, Do you know what the early brake pads were made out of (Im hoping not Asbestos)? Any tips for changing them? I ran over the chain that anchors the deck to the chassis during a test run. I may have to replace the entire chain or some links. How do I know what length of chain I need to use. Thanks.