The JBL Cruise is a perfect solution, if your bike does not have a radio (or a non-functional radio too!)
Simply use the motorcycle specific hardware (not included, $19.99 additional cost) and the Cruise will bolt on to your handlebars, and relocate your mirrors to a proper level. Wire 12v constant power and chassis ground, right to your battery, and boom! You have a bluetooth, powered stereo for your bike!
Volume and track controls on top of the speaker pods, weatherproof, no wires or cables to your phone. They sound great also.
