Changing gears on your bike enables you to tackle all types of terrain with ease. Riding up a hill is much easier in low gear, while high gears are ideal for speed on a level course. By shifting gears, you can maintain a constant speed despite the incline of your route. Your bike may skip gears occasionally as a result of improper shifting or mechanical failure.
Downshift to Stop
Coming to a complete stop without downshifting to a lower gear can lead to problems with your bike's transmission, including skipping gears. Taking off in high gear places a lot of weight on the transmission, since you must pedal hard to get the bike going. Downshift to a lower gear before you stop your bike to ease acceleration and decrease wear on your bike's transmission.
Pedal While Shifting
Pedal when you change gears. Pedaling moves the chain, which enables the derailleur to switch the chain from one sprocket to another and change gears. The bike cannot switch gears when the chain is stationary, so don't click the shifter when the bike is at rest. Taking off in a different gear from the gear in which you stopped may stretch the gear cables, which strains the bike and also makes terrible grinding noises. Pedal quickly -- but not too quickly -- for maximum ease of shifting. When you do shift, lighten up on the pedals, but keep them turning to smooth the change in gears.
Avoid riding your bike in the gears that force the chain into an extreme angle. Combining the inside, front sprocket with the outside, rear sprocket may wear out your chain and cause damage to the sprockets. Keep the chain parallel to the bike for maximum efficiency.
Strong cyclists riding bikes with flexible frames may cause accidental upshifting. If you stand up and pedal hard, you may cause the bike to slip gears to the next smaller rear sprocket. Some old-style bikes have a friction shift lever that requires adjustment to prevent this accidental change in gears. Bikes with internal gears and bikes with numerous gears and little space between them may slip out of gear if their cables are not adjusted correctly.