I've assumed I have to re-start the previous topic from the old forum to continue with the discussion?
I had a quick look at one of my B40WD's and, surprisingly, it is fitted with a 19T gearbox sprocket rather than the standard 17T. I am still restoring this bike and have not yet had a chance to ride it but assume the previous owner was happy with the much higher gear ratio. My other B40WD has standard gearing which is much too low for my liking and I will almost certainly change to an 18T gearbox sprocket to improve things slightly.