Ever pointed at something on your bike and not known what it's called? You're not alone. This is your simple walkround guide — every part explained in plain English, so you know what you're looking at, what it does, and when it matters.

The Toothed Cogs on Your Back Wheel — The Cassette

Look at the right-hand side of your back wheel. See that stack of toothed cogs? That's called your cassette.

Your chain sits on one of those cogs at a time. When you click the gear lever, the chain jumps up or down to a bigger or smaller cog. Bigger cog = easier pedalling (good for hills — less effort, slower speed). Smaller cog = harder pedalling (good for flat ground and speed — more effort, faster speed).

Think of it like the gears on a car — low gear to get going or climb, high gear to cruise.

Count the cogs. Each one is a gear. That's how many rear gears you have — and the number you need to match when buying a new chain.

The Big Toothed Ring by the Pedals — The Chainring

See the large toothed ring (or rings) that your chain wraps around near the pedals? That's called the chainring.

Some bikes have one, some have two or three. Each one is a different gear range. When you use your left-hand lever, the chain moves between these.

Count them too. Multiply by the number of cogs at the back — that's your total number of speeds.

3 chainrings × 6 rear cogs = 18 speed
1 chainring × 11 rear cogs = 11 speed (written as 1x11)

Simple version: The big ring(s) by your feet. Count them, multiply by the rear cogs — that's your speed.

The Chain — The Loop That Makes It All Work

The chain connects the chainring at the front to the cassette cogs at the back. Simple as that.

One important thing — chains are sized to match your gears. Count your rear cogs and that's the chain you need. A 6-speed bike needs a 6-speed chain. An 11-speed bike needs an 11-speed chain. Get the wrong one and it won't sit properly.

Keep it clean and oiled and it'll last much longer. We recommend Weldtite TF2 Cycle Oil — a few drops per link, wipe off the excess. Done.

Simple version: The loop that connects everything. Match the chain speed to your number of rear cogs.

The Little Arm That Moves the Chain — The Derailleur

See that small hinged arm hanging just behind the rear cogs? That's the rear derailleur (say: deh-RAIL-yer). It's what physically pushes your chain across the cogs when you change gear.

Some bikes also have a front derailleur — a smaller clip near the chainrings that shifts the chain between them.

If your gears are slipping or crunching, the derailleur usually just needs a small adjustment rather than replacing.

From left to right: cassette (the cogs on the rear wheel), derailleur (the arm that moves the chain), chain, and chainring (the large ring by the pedals).

Simple version: The hinged arm behind the rear cogs. It moves the chain. If gears slip, it needs a small tweak.

Indexed Gears — Why Your Gears Click Into Place

Each click of your gear lever moves the chain exactly one cog. That precise click is called indexing.

When it's set up right, every gear change is clean and instant. When it drifts out — usually because the cable has stretched slightly — the chain rattles or ticks between cogs. That's called being out of index.

The fix is usually a small turn of the barrel adjuster — the little knob where the cable enters the derailleur. One or two turns and it clicks back into place.

Simple version: Gears clicking cleanly = indexed correctly. Rattling or slow to change = needs a small adjustment.

The Bits That Stop You — The Brakes

Most bikes have one of three types:

Rim brakes — rubber pads that clamp onto the metal rim of the wheel. Simple and light. Common on older bikes and road bikes.

Disc brakes — pads that clamp onto a metal disc (called a rotor) bolted to the centre of the wheel. Much more powerful, especially in wet weather. Standard on modern mountain bikes.

Drum brakes — hidden inside the wheel hub, very low maintenance. Common on kids' bikes and city bikes.

When the brakes feel spongy or the pads are worn, that's when to replace them. We stock Shimano brake pads if you need them.

Simple version: Rim brakes clamp the wheel edge. Disc brakes clamp a metal disc. Drum brakes hide inside the hub. Spongy = time to replace the pads.

The Spindle Inside the Frame — The Bottom Bracket

The bottom bracket is hidden inside the frame where the pedals meet the bike. It's a bearing that lets the cranks spin smoothly. You never see it, you rarely think about it — until it starts creaking. A creaking bottom bracket is one of the most common causes of mysterious bike noises.

Simple version: The axle your pedals spin on. You can't see it. If your bike creaks when you pedal, this is often why.

The Bearing at the Top of the Fork — The Headset

The headset is the bearing that sits at the top of the front fork, inside the frame. It's what lets you turn the handlebars smoothly. If your steering feels loose or notchy, the headset needs adjusting or replacing.

Simple version: The hidden bearing that lets you steer. Crunchy or loose steering = headset needs attention.

The Handlebars and the Bit That Holds Them — The Stem

The handlebars are what you steer with — you can see them right in front of you. The short piece of metal that connects them to the fork is called the stem. Raising or lowering the stem changes how upright you sit.

Flat bars — straight across. Upright, easy to control. Most family bikes, hybrids, and mountain bikes.
Drop bars — the curved ones that loop downward. More aerodynamic. Common on road bikes.

Simple version: Handlebars = what you hold. Stem = the short bit connecting them to the bike. Higher stem = more upright and comfortable.

The Rubber on the Handlebars — Grips and Bar Tape

Grips are the rubber or foam sleeves on flat handlebars — the bit your hands actually touch. They absorb vibration and give you something comfortable to hold. Easy to replace when they wear out or get slippery.

Bar tape is the wrapped tape on drop handlebars — same job, different form.

Simple version: The rubber your hands grip. When they get worn or slippery, replace them — it's a cheap easy fix.

The Seat and the Tube It Sits On — Saddle and Seatpost

The saddle is the seat — the thing you sit on. The tube it clamps onto is the seatpost, which slides up and down inside the frame to set your height.

At the bottom of your pedal stroke, your leg should have a slight bend — not fully straight, not cramped up. Get that right and cycling becomes much more comfortable immediately.

Simple version: Saddle = seat. Seatpost = the tube that sets the height. Slight bend in the knee at the bottom of the stroke = correct height.

The Bendy Bit at the Front — The Fork

The fork is the curved piece at the front of the bike that holds your front wheel. You can see it clearly — it's the two arms that drop down from the handlebars to the wheel.

On bikes with front suspension, the fork has two tubes that compress when you hit a bump — called a suspension fork. On a rigid bike, it's one solid piece — lighter and lower maintenance.

Simple version: The two arms holding your front wheel. Springy = suspension fork. Solid = rigid fork. Rigid is lighter and easier to maintain.

The Centre of the Wheel — The Hub

The hub is the central cylinder in the middle of the wheel — the part that spins on the axle. The spokes radiate outward from the hub to the rim. The rear hub is where the cassette fits on.

Well-maintained hubs spin freely and last for years. A grinding or rough-feeling wheel usually means the hub bearings need attention.

Simple version: The centre of the wheel everything spins around. Grinding feeling = bearings need servicing.

The Thin Metal Rods — The Spokes

Spokes are the thin metal rods you can see radiating from the hub out to the rim. They hold the wheel in shape under load.

If one breaks, get it replaced quickly — a wheel with a missing spoke will go out of shape and can cause further damage.

Simple version: The thin rods holding the wheel round. One breaks = get it fixed quickly before the wheel warps.

The Metal Hoop — The Rim

The rim is the outer metal hoop the tyre sits on — the large ring you can see around the outside of the wheel. On rim-brake bikes, this is also the braking surface — keep it clean and replace it when it wears thin.

Simple version: The metal hoop the tyre wraps around. On older bikes it's also where the brakes clamp.

How the Wheel Stays In — Quick Release and Thru-Axle

Quick release (QR) — a lever-operated skewer through the hub. Flip the lever open to remove the wheel without any tools. Very common on older and mid-range bikes.

Thru-axle — a bolt that threads all the way through the fork and hub. More secure and stiffer. Standard on modern mountain bikes and disc brake bikes.

Simple version: QR = flip a lever to remove the wheel. Thru-axle = unscrew a bolt. Both let you remove the wheel without tools (or with a quick turn).

The Rubber Bit on the Outside — The Tyre and Inner Tube

The tyre is the rubber outer layer you can see — it grips the road and takes the wear. Inside it sits the inner tube — the inflatable rubber ring that holds the air. When you get a puncture, it's almost always the inner tube that's gone, not the tyre.

Two things to match when buying a new tube:

1. Wheel size — printed on the tyre sidewall (e.g. 26", 27.5", 700c)
2. Valve type — Schrader (wide, like a car tyre valve) or Presta (thin, with a small nut on top)

We stock Impac 26" inner tubes and 27.5" inner tubes — free UK delivery over £18, or collect same day from Hadfield.

Simple version: Tyre = rubber outer. Inner tube = inflatable ring inside. Puncture = replace the tube. Match the size and valve type printed on your tyre.

The Bits You Push With Your Feet — Pedals and Cranks

The pedals are the flat platforms your feet push on — easy to spot. They attach to the cranks — the arms that connect the pedals to the chainring.

One thing that catches people out: the left pedal has a reverse thread — it tightens anti-clockwise. Remember that if you ever remove them.

Simple version: Pedals = what your feet push. Cranks = the arms they attach to. Left pedal tightens the wrong way — don't force it.

The Main Body of the Bike — The Frame

The frame is the skeleton of the bike — the triangular structure you can see in the middle of everything. All the other parts bolt onto it. The main tubes have names:

• Top tube — runs from the handlebars to the seat
• Down tube — runs from the handlebars down to the pedals
• Seat tube — the vertical tube the seatpost slides into
• Chainstays — the two tubes running from the pedals back to the rear wheel
• Dropout — the slot where the rear wheel axle fits in

Simple version: The triangular skeleton everything else bolts onto. The size and shape of the frame determines how the bike fits you.

FAQs

What's the lever on my handlebar called? The shifter — it moves the chain via the derailleur.

What's a quick release? A lever on the wheel axle that lets you remove the wheel without any tools.

What's a groupset? All the gear and brake components made to work together — shifters, derailleurs, cassette, chainring, brakes. Shimano is the most common brand.

What does 1x mean? One chainring at the front. Simpler, lighter, increasingly common on modern bikes.

What's a puncture repair kit? Patches, a rougher, and glue to seal a punctured inner tube. We stock the Weldtite puncture repair kit — everything in one pack.

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Still not sure what something is? Come into Peak Bike Station in Hadfield and we'll show you round your bike in person. No question is too basic.

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