The proper length of chain and the right rear derailler (long cage), I can get 52/34 and 30/11 to work. This is full range of 27 speeds on an Actionbent Tabpole. At 30/11, the cage is only a 1/2" from crashing into the cluster; at 52/34, I have still have about room to move the cage forward about another inch. It takes a little fine tuning. I would lock out the larger gears on the rear cluster until you get this corrected (adjust the derailler stop screw).