do you have a usb power supply that will work on a motorcycle for a gps and a mp3 player that has 4 ports?
A Harley Hub would be a cool product!
Seriously, no. In addition to the problem of wiring to a input power source, all our hubs follow the USB 2.0 standard protocol, which means they only deliver full per-port output power (500mA) when connected to a host (computer) that’s turned on and has negotiated with the device for that higher power.
So wouldn’t be a good match for the bike.
If you really want charging on the road, and can dabble in electronics a little, you might want to check out something like this: http://www.ladyada.net/make/mintyboost/
A pretty cool creation, with instructions.