Discovering a love for cycling but struggling to get to grips with the jargon?
Or do you want to explain what’s wrong with your bike to a mechanic, but don’t know what the broken part is called?
Fear not – we’re here to help!
In this article, we’ll get you familiar with all the key parts of a bicycle. You’ll know your cassette from your crank arm in no time!
Don’t worry if you feel daunted by the task of learning all the different bike parts’ names – to keep it simple we’ve broken them down into 5 easy groups (with pictures):
- #1: The Frame
- #2: The Wheel
- #3: The Drivetrain
- #4: The Handlebars (and Steering Components)
- #5: The Brakes
Ready to get clued up on your bike parts’ names?
Let’s get started!
#1: The Frame
The frame is the main structural body of your bike, to which the other parts of a bicycle are attached.
Bike frames are usually made of aluminum, titanium, or steel, though high-end racing bike frames sometimes use carbon fiber.
- Top Tube – the tube which runs across the top of the frame.
- Down Tube – the tube which descends from the front of the bike towards the pedals.
- Seat Tube – rises from the bottom of the down tube towards the saddle.
- Head Tube – The short section running between the top tube and the down tube.
- ‘Triangle’ – the empty space formed in the middle of the four tubes.
- Chainstay – extends backward from the point where the down tube meets the seat tube.
- Seatstay – drops from the rear end of the top tube to meet the back of the chainstay.
Strictly speaking, the saddle, the seat post, and the fork are not part of the frame – but we’ve included them here to help keep things simple.
- Fork – the double-ended section which the front wheel attaches to.
- Saddle – the bike’s seat.
- Seat Post – extends upwards from the seat tube to hold the saddle.
#2: The Wheel
The humble bike wheel may seem simple, but it has a combination of key components that work in tandem to keep you rolling!
- Rim – the circular metal band of the wheel to which the tire and inner tube are fitted.
- Tire – the outer layer of rubber which touches the ground.
- Inner Tube – the inflatable rubber tube housed between the tire and rim. Take a look at our expert guide to replacing an inner tube here!
- Valve – pokes through a hole in the rim and is used to inflate the inner tube. Most valves are either the long, thin Presta valves (normally found on road bikes) or the wider Schrader valves (more common on mountain bikes).
- Spokes – thin rods connecting the rim to the wheel’s hub.
- Hub – the central part of the wheel, containing ball-bearings that allow the wheel to spin.
- Fastening (Quick-Release) – there are several methods of fastening the wheel to the frame, the most common of which is the quick-release skewer. Other fastenings include thru-axles and hexagonal axle bolts.
#3: The Drivetrain
The drivetrain refers to all the parts of a bicycle which are used to drive it forward.
- Chain – transfers energy from the turning pedals to the rear wheel, propelling the bike forwards. A well-maintained chain is the key to extending the lifetime of all the other parts of a bicycle’s drivetrain – check out our expert guide to removing and replacing a bike chain here!
- Crank Arms – the arms which connect the pedals to the chainset.
- Chainrings – the front set of gears. The larger the chainring, the harder it is to pedal, and the further each rotation will push you forward.
- Chainset – the name given to the crank arms and the chainrings as a unit.
- Cassette – the rear set of gears. Usually contains anywhere between 5 and 12 sprockets (the name for each individual gear ring).
- Derailleurs (Front and Rear) – the mechanisms which shift the chain between the different chainrings at the front and sprockets at the rear. The derailleurs are controlled by gear levers, usually found on the handlebars but occasionally mounted on the down tube.
- Derailleur Arm – the arm which extends from the rear derailleur, with pulleys to feed the chain through. The derailleur arm is spring-loaded to remove slack from the chain when using smaller gears.
- Derailleur Hanger – the metal piece connecting the rear derailleur to the frame. Also known as ‘frame-savers’, they’re intentionally designed to bend under pressure as a failsafe to prevent damage to the frame, which is far more costly.
#4: The Handlebars (And Steering Components)
As well as providing steering control, a bike’s handlebars are (usually) home to the rider’s controls for the brakes and gears.
Handlebars come in many different forms. The type shown here are drop handlebars, commonly found on road bikes as they allow for a more aerodynamic rider position, whereas flat bars will usually be found on mountain bikes.
- Brake And Gear Levers – the position of the brake levers depends on the style of the handlebar. On drop handlebars, the brake and gear controls are sometimes combined into a single pair of levers which are squeezed to apply the brakes or pushed to the side to change gear. Flat bars are more likely to use trigger shifters.
- Brake Hoods – protective covers for the brake levers on drop handlebars, which are normally ergonomically designed to be a comfortable handhold while riding.
- Stem – connects the handlebars to the steerer tube (which extends from the top of the fork). There are two main designs: quill stems (which are ‘L’-shaped and drop directly into the headset) and threadless stems (which clamp directly around an extended steerer tube protruding above the headset).
- Headset – the name for the collection of parts that allow the fork and steerer tube to rotate within the head tube, acting as the point of contact between them. Typically consists of a pair of cups containing ball-bearings, placed at either end of the head tube.
#5: The Brakes
There are two main types of bicycle brakes: rim brakes and disc brakes.
Rim brakes are more common on road bikes and are generally cheaper and easier to maintain. It’s also much easier to quickly change a wheel with rim brakes, which – along with their lighter weight – is partly why they’ve historically been preferred by professional road-racing teams.
There are many different styles of rim brakes. The type shown above are called dual-pivot side-pull caliper brakes (yes, we know that’s a bit of a mouthful), which are the most common variety used on modern road bikes.
Rim brake components typically include:
- Brake Pads – usually made of rubber, they’re pressed against the rim to create friction to slow the bike down.
- Shoes – the part which holds the brake pad.
- Caliper Arms – the moving parts which press the brake pads into the rim. In this style of rim brake, the two caliper arms meet at a pair of pivots centered above the wheel.
Disc brake components include:
- Rotor – the metal ‘disc’ attached to the wheel hub, which gives these brakes their name.
- Calipers – fitted on either side of the rotor, they squeeze together around it when the brake lever is pulled to create friction, slowing the bike down.
Now you’re familiar with all the parts of a bicycle, it’s time to get back in the saddle – or the workshop – to put your new knowledge to use!
Learning how all the components of your bike work is a great skill for any cyclist. This knowledge can help you understand and identify when, where, and why there’s a problem with one of your bike parts or with your overall setup.
Getting to grips with all the different bike parts’ names can take a little while – but you can always refer back to our diagrams to check in the meantime!