[glang]

glang, I just had another thought that may help you: Compare the size of the R/R (which is probably capable of dealing comfortably with up to 150W) to the heatsink on even a small size audio power amp. I think you'll find a much larger heatsink on an equivalent audio amp and this physically shows the extra heat implications of trying to variably control the power flow. Hence why R/Rs use switching techniques, even transistor regulated ones (although it does mean that the alternator coils and wiring have to take the thermal strain - there's nowt for free!)

Dont forget though that theres far more forced cooling available on a moving bike especially as, handily, more speed equals more heat to be dissipated.....