Originally Posted by
Drew Eckhardt
They make front hubs with generators which can power lights and even other devices with USB interfaces.
Does anyone know if you can charge a Di2 battery while riding?
I've got one for my commuter that I never bothered to install. Tons of drag, and weighs more than my crank. Wouldn't dream of installing it on a race bike. For some people though, a front hub that powered a di2 system would be ideal.