This DR is on a Giant Iguana MTB, triple crank, the lever system is a two lever contraption up on the bars.

Do I need to post pics or does someone know the drill for setting the adjustment on the DR. I have the cage as close to the large sprocket as possible but I'm not sure about the function of the handlebar control, when to pull the cable slack, etc.I can get two sprockets to shift fine but the third just doesn't want to come. The shift to the large sprocket to the middle and back is OK but then the small sprocket doesn't want to drop or vice versa. It seems like the throw is too short to get all three covered.

The bicycle was inherited like this. It's duty will be studded tires and a winter commuter so I am riding it no problem, it just bugs me that I can't get it right, I have a book and read Sheldon. I am a fair motorcycle and vehicle mechanic.

Any ideas?