I've been wondering if the new Bosch CX motor does exactly what you asked for, in terms of building in free movement of the chainring, although I haven't seen any of the reviewers directly address this. All they're saying is that the new motor "decouples" the inner gears from the outer gears, so that you don't get the dreaded clutch rattle, but I can't tell what exactly happens when the top stretch of chain gets yanked on (ie. does the ring spin backward freely?). It seems like it must, or else when it catches it would cause the rattle due...