Ensure that the bicycle is in a stationary position then find the front derailleur starting with the left gear lever, follow the cable until it enters a mechanism near the front gears. Locate the derailleur adjusting screws, which are two small adjacent screws on top of the mechanism, ask someone to assist you by holding the rear wheel of the cycle off of the ground, Loosen the L screw an additional turn if you still cannot shift. Shift into the big chain ring once you have set the inner limit. If the chain does not go into the big chain ring, loosen the H screw. Shift the rear derailleur. Finally fine-tune your adjustment as necessary.