Mountain Bike Gear Shifting 101

Riding your mountain bike is great exercise, but it’s not cheating to let the gears help you maximize your muscle power; that’s their reason for existence. Choosing a gear on your bike is essentially choosing your effort level. Getting a good grasp on the functioning of your mountain bike gear shifting will help you to ride faster, travel farther, and enjoy it much more.

The Mountain Bike Groupset

Without a groupset, or drivetrain, a mountain bike is just a glorified scooter. The groupset is like an engine room, containing all of the pieces that provide the bike with its forward motion. Here are the critical parts of the mountain bike groupset:

• Crankset: this includes the crank arms, front cogs (called chainrings, also known as sprockets), and the crank arm connecting axle. The number of chainrings determine the number of forward gears: the latest trend on mountain bikes is to have fewer chainrings. 
• Cassette: the cogs that connect with the rear wheel, the cassette determines the number of back gears: most mountain bikes have from eight to twelve.
• Bottom bracket: this is attached within the frame, where the crankset uses a set of bearings to spin.
• Chain: connecting the crankset in front to the rear cogs, the chain enables you to turn the wheels as you turn the pedals.
• Derailleurs: these guide the chain through the cogs. Recent technology has improved these devices on higher caliber mountain bikes to reduce friction, quiet the ride, and lessen the chances of dropping the chain.
• Shifters: these are directly linked to the derailleurs and control gear changes. The typical mountain bike has a trigger shifter, which uses the thumb or forefinger.
• Brakes: in the last decade, disc brakes have become the most popular type of brake, although you will still find rim brakes on some older or less expensive bikes. Premier mountain bikes feature hydraulic braking systems, while mechanical disc brakes are standard on lower-end bikes.

Gear Ratios

The function of bike gears is to allow your legs to efficiently use an array of speeds and gradients. Gear ratios determine the spin of the rear wheel related to the front crank. Lower gears turn the rear wheel less related to the crank turn. Higher gears result in more spin on the rear wheel with one crank revolution.

Mountain bikes utilize mostly low gears, enabling you to climb steep hills and navigate loose terrain. For simplicity, ease of operation, and reliability purposes, contemporary mountain bikes are reducing the number of front gears, utilizing just one or two chainrings. 

Mountain Bike Gear Shifting

While shifting may seem complex at first, practice will increase your muscle memory and it will become more instinctive. Here is an explanation of the basic shifting procedures for conventional mountain bikes: 

• For bikes with multiple chainrings, the left-hand shifter moves the front chainrings. (If you have only one chainring, skip this part.) To adjust the ease of pedaling, try the following:

• If there are three chainrings in the front, start with the chain on the middle ring and adjust up or down.
• For more resistance and harder pedaling, move the chain to the largest front chainring
• To make pedaling easier, move the chain to the smallest chainring in front
• The right-hand shifter moves the back cassette

• to loosen resistance on the pedals, move the chain to the larger back cogs
• To increase resistance on the pedals, move the chain to the smaller back cogs

Useful Tips

As you are getting accustomed to the bike gear shifting basics, here are some helpful pointers to keep in mind:

• Use an easier gear: while it might seem faster to use a harder gear because you are turning the pedals slower, it will zap your energy much faster due to the force it takes to move the wheel. It’s also harder on your knees. Instead, focus on pedaling at the highest comfortable speed. 
• Prepare for the terrain: when you see an incline, shift before you start the climb. If you must shift on a hill, do it gradually, relaxing pedal pressure mid-shift. A grinding sound signifies too much force on the pedals, which can damage your drivetrain.
• Don’t cross-chain: moving gears to opposite ends of the front and rear cogs is known as cross-chaining, and it’s bad for your drivetrain. Keep as close alignment as possible between the front cogs and rear cassette.
• Don’t double shift: if you have multiple front chainrings, don’t simultaneously shift the rear and front shifters, as this can stress the drivetrain. You should remember to utilize the front chainrings for big shifts, saving the rear cogs for fine-tuning the gears.

Trouble-Shooting

If you experience bike gear shifting problems such as mis-shifting, skipping, or grinding, here are a few common culprits to investigate:

• Poor adjustment: cable tension issues can cause sluggish upshifts or slow downshifts.
• Bad cables: poor quality, old, kinked, or dirty cables can hinder a mechanical drivetrain from shifting properly.
• Cable housing: shift consistency and quality can be affected by cable housing that is too long or too short.
• Alignment issues: the rear derailleur hanger on modern bikes is relatively fragile and easily knocked out of alignment by simple, everyday bumps on the trail.
• Front shifting: incorrect derailleur height is a common issue that can affect quality of front shifting.
• Worn or rusty chains: to avoid drag and sluggish shifting, chains should be clean, lubricated, free from kinks, and of the proper length. If you have a problem with a rusty chain this is how you can solve it.
• Old parts: adjustment can go a long way, but at some point, your chain, chainrings, and cassette are likely to wear out, as are derailleur springs and shifters.
• User error: it’s possible that you’re just doing it wrong. Shifting on a hill or while otherwise powering the pedals, or failing to click the gears properly into place will yield poor shifts and could damage your bike. 

Mastering gear shifting on your mountain bike takes practice, but will soon become second nature and you’ll be riding farther, faster.