How to Use Mountain Bike Gears
Step 1 Start pedaling your bike until you reach a steady, comfortable cadence. When you're riding a flat, the chain should be on the large chainring, by your front derailleur. The shifter on the right side of the handlebar will control the front ring, while the shifter on the left side will control the rear ring, or the cassette. Always pedal while shifting gears. Bicycle Pedal Manufacturers
Step 2 Click your front shifter to move into your middle gear, which will switch the chain to the middle chainring. This gear is used for slight climbs, when pedaling against moderate winds, or when traversing soft ground.