You'd a thought nowadays there would be a switching reg for bikes, soo much more efficient than shunt or series type regulation, which just dump power at the reg rather than just not using it like in a switching unit. I know switch modes dont like unstable input voltages but with the speed of modern electronics the manufactories would be making them.
Tho i suppose the cost of development etc makes it unviable, when a cheap shunt reg does it job well enough for a given mount of time and money.
Cheers
Ian

Ian, you could consider both shunt and series regulators to be switch mode its just that one switches the generated current back to the source (shunt) and the other switches the source from the load (series). Why the shunt type has been historically dominant may be due to the availability of suitable or cheap electronic devices for the series type until recent times.

If anyone cares, I tested the reg/rec today. 14.76 volts at idle and 14.83 at 5k rpm. I'm calling that a win.