Ask a Mechanic: Ultegra Di2 on CX Bikes and Hub Troubleshooting Evan2015-03-20T13:08:48-08:00 Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers Ask a Mechanic: Ultegra Di2 on CX Bikes and Hub TroubleshootingEvan2015-03-20T13:08:48-08:00