Nothing major. changed the tunnel stiffeners on the from aluminum to steel. the 163s only have tipped up rails 155s are flat. A few oil lines are routed differently but the 2011s are being recalled to have that done it seems anyways. other than that just alot more options it seems.
They re did the motor mounts,plus added more traction to the outside edge of the running boards,put a wrap around some of the electrical harness's as well.I believe the injectors are also different
Here are a few things I can think of:
-went to Bosch injectors
-remap
-more traction on outside edge of running boards
-tunnel stiffeners stronger
-better engine mounts
-chaincase glued to chassis now to help stiffen up chassis even more
-re-route wiring, cleaner design and put covers on them
-exhaust design is slightly different... I think just different vendors.
Reports from 2011 and 2012 owners are saying the 2012 feels stronger HP wise and performs better then the 2011's. I haven't ridden a 2011 to compare mine to.