Thanks for the comments. It was an interesting project, inspired as these things so often are, by some idle conversation in the pub about the insufficient range of the 8-speed hub for touring use, when low gears for steep hills are needed!
I've tried combination hub/rear derailleur before, but this seemed a much simpler concept and much easier to alter gearing as chainrings are very quick to change.
Thanks for the comments. It was an interesting project, inspired as these things so often are, by some idle conversation in the pub about the insufficient range of the 8-speed hub for touring use, when low gears for steep hills are needed!
I've tried combination hub/rear derailleur before, but this seemed a much simpler concept and much easier to alter gearing as chainrings are very quick to change.