Re: sprocket against spokes myth
This is another case of the gospel, as we know it, not being quite so absolute. As with most methods, ideas and avenues there is, as they say, "more than one way to skin a cat".
What works for some will not be so successful for another. We could site examples of these things all day and there would always be opposing opinions based on what works for some and what doesn't. Camlifer is right about the tighness and alignment of his sprocket. If the sprocket is tight and doesn't move then there is no wear. Its the friction of movement that will damage the spokes, not just the fact that there is metal to metal contact. Take a look at any machine and you'll see metal bolted to metal. Its only when things get loose that the wear begins. The only issue I see that might be a problem would be the distortion of the spokes from being bolted to a flat surface when they have a natural slant inward. I've not run into an alignment problem that required moving the sprocket outward that far but if I ever do I might consider mounting it without the rubber, but you can be sure that I'd keep a close eye on that potentially trouble prone area. Just my thoughts
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"