pic: 499 Prototype drivetrain final layout

[Kevin Sevcik]

I would be highly interested in a sort of synthesis of these two designs. I like Madison's design for the lightness of the frame components, but I think there's a lot of advantage to the style of bearing blocks the Andrew has designed. As I understand it, the main purpose of 8020 is to simplify chain tensioning, and Andrew's block only need three screws on the top for adjustments. Madison's, while somewhat lighter, would take require loosening 2 screws outside the frame and 2 screws inside the frame, which seems more troublesome to me. Admittedly, the loading on Andrew's blocks wouldn't be quite what you'd like, but I don't think it would really present a problem. If Madison's using 1515 Lite instead of 1010 on those side rails you could probably bolt them straight on.