A bicycle may not be the most sophisticated piece of equipment, but maintaining your ride or describing a bike issue without knowing the various parts can be challenging. We’ve created this bike parts glossary to help you enjoy your bike to the fullest. In it, we’ve listed all the essential parts of a bicycle so you can quickly learn more about your bike, maintain it, and get helpful information if you need to repair or modify it.
Bicycle frame parts
The frame of your bicycle is its central body. It connects the front and back of your bike and serves as an anchor for your seat. Diamond frames are the most common type of bicycle frame. They’re shaped like a diamond, with two triangle-shaped sections on either side consisting of six tubes (described below).
The top tube (also called the cross-bar) is the tube you step over to sit on your bike seat. It runs parallel to the ground (sometimes straight or at an angle) and connects the seat tube to the top of the head tube, which runs beneath your handlebars. Depending on the length and angle of your bike’s top tube, it might be more or less difficult to mount and ride your bike.
The down tube is situated directly below your handlebars and runs from the head tube to the pedals. It usually features the brand name of your bike and is an ideal spot to mount a water bottle.
The head tube is located at the front of your bike’s frame. It connects the handlebars to the wheel. The head tube also contains the fork steerer tube, which connects to the headset and allows you to steer your bike by turning the front wheel with your handlebars.
The seat tube connects your bike’s saddle (or seat) to the pedals. The seat post sits inside this tube, allowing you to adjust the height of the saddle by sliding the seat post up or down into the seat tube. The angle of your bike’s seat tube can affect your overall cycling efficiency and aerodynamics, as well as your stability on the bike. For instance, a seat tube with a slack angle (63 to 66 degrees) will be more comfortable and stable, but you might not be able to pedal as efficiently.
The seat stays are the thinner tubes on the bike’s frame that run diagonally from underneath the saddle to the rear wheel hub.
The chain stays are the thin tubes that connect the pedals to the rear wheel hub. They run parallel to the ground along the chain on either side of your bike’s back wheel.
Front parts a bike
The front parts of a bike are all located at the front, near the handlebars and front wheel.
The headset connects your bike’s frame and wheel fork. It’s made up of two cups that allow your handlebars to turn and steer your front wheel.
The handlebars are what you use to steer your bike. They consist of two handles connected by a tube, which attaches to the bike’s frame via the stem.
The stem is a small tube that sticks out from the top of the head tube. It connects the steerer tube of the wheel fork to the handlebars.
Brake levers/gear shifter
The brake levers are the parts on the handlebars that you squeeze to slow down or stop your bike while riding. Small cables called brake cables are attached to each lever and run down the bike’s frame to the wheels, where they connect to the brakes. Some brake levers are combined with a gear shifter, allowing you to also change gears while you ride.
The fork is the bar that runs along both sides of the front wheel. It connects your bike’s front wheel hub to its frame. At the top of the fork, the steerer tube is tucked inside the head tube, which connects to the headset.
Lower parts of a bike
The lower parts of a bike are all at the back of it, behind and beneath the seat. They consist of the following:
The crankset is also called a chainset. It helps you pedal your bike and turn the back wheel. It’s made up of the chainrings (the part of the bike that the chain wraps around) and the crank arms, which are attached to the pedals where you rest your feet.
Your bike’s pedals are the small flat platforms where you rest your feet when you cycle. As you push down on them, they transfer power to the back wheel and propel your bike forward. The two main types of pedals are flat/platform pedals and clip-in pedals. With flat/platform pedals, you rest your feet on top. With clip-in pedals, you use special cleat shoes that attach to them.
The bottom bracket sits at the bottom of your bike frame in the center of the crankset. It’s the part of a bike that the crank arms rotate around when you pedal and consists of a spindle and bearings, which allow the spindle to rotate.
The chain is the part of your bike that loops around the chainrings and your bike’s back wheel cassette. When you pedal, the chain rotates with these two parts to turn the back wheel and propel the bike forward.
The front derailleur is an essential component of a bike for shifting gears. It moves the chain from one chainring to the other, reducing or increasing the pedaling difficulty. Only bikes with more than one chainring have front derailleurs, but on bikes that do have it, the part is attached to the bike’s frame with a bracket.
The cassette is attached to the hub of the rear wheel. It’s made of a group of sprockets (or cogs), which are the rear gears of the bike.
The rear derailleur works with the jockey wheel to help you change gears as you cycle. It does so by transferring the chain from one gear wheel to another.
If your bike has gears, it has two jockey wheels, each playing a different role. Located on the rear derailleur, the upper jockey wheel, or the guide pulley, helps you shift gears and moves the chain across the sprockets on the cassette. The lower jockey wheel, or tension pulley, keeps the chain taut when you’re shifting gears.
Bicycle wheel parts
The bike wheels are on the front and bike end of your bike, and they consist of the following parts:
The hub is the component at the center of your bike’s wheels. It’s at the base of the fork and contains the bearings that allow your wheels to rotate.
Spokes are the thin metal rods that connect the rim of your bike wheels to the hub in the center of the wheel.
The rim is the metal circle that makes up the outside of your bike’s wheels. They’re typically made of aluminum. Your bike’s tires are attached to the rim, and the spokes are connected to it via spoke nipples, which are threaded through the rim.
The tires are mounted on your bike’s wheel rims. They make contact with the ground as you cycle. Each tire has an outer layer made of rubber and an air-filled inner tube inside its center. However, some tires, known as tubeless tires, do not have a tube inside. Different types of bikes use varying tires. For example, mountain bikes have wide and heavy tires, while road bikes have thin tires with a lot of tread for increased traction.
The valve is a small component on your bike’s tires. They allow air to enter but prevent it from escaping, so you can inflate your tires.
Bicycle seat parts
The saddle is the seat of your bike where you sit while you cycle. Depending on the type of bike you have, the shape and size of the saddle can vary.
The seat post attaches to the saddle and connects it to your bike’s frame. You can adjust the height of the seat post to the most comfortable position as you ride.