I supplement my Supernova with an Exposure helmet light for when I'm doing 4kph up some fucking gravel fucking climb. Even when moving fast enough for the Supernova to light up, it's still nice on rough roads to have a helmet light for picking better lines.
Off road I rely on batteries - a couple of Ay-Up lights, one wide angle on the bars, one narrow beam on the helmet. They're from Oz, so I'm assuming you'll approve. They worked well on the One Night In Thetford 12 hour race.
I supplement my Supernova with an Exposure helmet light for when I'm doing 4kph up some fucking gravel fucking climb. Even when moving fast enough for the Supernova to light up, it's still nice on rough roads to have a helmet light for picking better lines.