I have a Caadx with double 46, 36 chainring up front and 12-28 in the back with a 105 derailleur. The gearing is a bit stout for some of the hills I encounter on road rides. What would be the best way to go? Go to 12-36 in the rear or change out the 36 for a 34 or even a 32. Would the rear derailleur be able to handle going from a 28 to a 36?