Understanding how your bike gears work can help you choose the right components when you’re bike shopping. It will also help you get the most enjoyment out of your bike when you’re out on a ride.

There are five main parts of the standard bicycle that let you shift gears. They are comprised of the following:

• Front chain-rings (a.k.a crank-set)
• Rear cassette
• Chain
• Derailleurs
• Shifters

The crank-set, rear cassette, chain, and derailleurs are known collectively as the drivetrain, pictured here:

Chain-rings:

Bikes have one, two or three front chain-rings, also known as the crank-set. A bike with two chain-rings is called a double. A bike with three chain-rings is called a triple. Each chain-ring has a number of teeth on it where the chain connects.

Cassette:

Your bike’s rear cassette is the stack of cogs (gears) mounted on the right-hand side of your rear wheel, with the small cog farthest from the wheel and the large cog closest to the wheel. Each cog has a number of teeth on it where the chain connects.

Chain:

The chain connects to the teeth on your front chain-rings and the cogs on your rear cassette so that when you pedal, the chain-rings and cogs turn the wheels and the bike moves forward.

Derailleurs:

It moves the chain between the front chain-rings or between the rear cogs. Cables run from your shifters to your derailleurs. When you press on your shifter, it moves your front or rear derailleur so the chain moves where you want it to go.

Many bikes have front and rear derailleurs. Some mountain bikes have only a rear derailleur and therefore come with only one shifter.

Shifters:

Shifters let you move the chain between your front chain-rings and the cogs of your bike’s rear cassette. Each shifter controls one cable attached to one derailleur.

On-road bikes, the shifters are mounted either on the handlebar or they’re integrated with the brake levers. In older road bikes, they’re on the down-tube or on the ends of your drop bars. On mountain bikes, the shifters are mounted on the handlebar.

Using Your Shifters and Gears

Gears and shifters help you maintain cadence a constant paddling speed during your ride. Generally, a higher cadence on an easier gear is more efficient than paddling slower in a harder gear.

Pushing hard gears might seem faster, but it will sap your strength more quickly, and it can take a toll on your knees.

At a high cadence, you’re working in your aerobic zone, which means your muscles can clear lactic acid and postpone fatigue.

The optimum cadence for road biking is around 80–100 rotations per minute. For mountain biking, it should also feel like you’re spinning your legs, not powering slowly, though it’s harder to keep cadence on technical terrain.

Once you find a comfortable cadence, shift your gears to help you maintain that cadence for as much of your ride as you can.

Proper Shifting Technique

Shift the chain between the rear cassette cogs for small changes and between the front chain-rings for big changes, but not both at the same time. Only use one shifter at a time, or you may miss-shift, jam the chain or drop the chain off the chain-rings or cassette.

Try to anticipate the terrain, and shift right before you start climbing, not halfway up when you’re nearly stopped with maximum pressure on the pedals.

On flats, it’s okay to shift through several gears at a time. If you do shift on a hill, shift one gear at a time, and try to momentarily release pressure from the pedals as you’re shifting.

When you shift, don’t pick a gear that will put your chain on opposite extremes of the front cogs and rear cassette at the same time. Called cross chaining, this is where you’re most likely to drop or break your chain. Those same gears can be achieved with different combinations of chain-rings and cogs.

BEST GEAR RATIOS FOR DIFFERENT TERRAINS