# Two\-Wheeler Feature Showcase

A gallery walk\-round of a generic 700c hybrid bicycle: its frame, wheels, gears, brakes, steering, materials and hidden bearings, with live colour selection

By Agrim Anand

Topic: Machines

[Open the interactive Jig](https://ask.jig.com/j/xYUvqtQVUyA9)

## Guide

### 1. Meet the two\-wheeler

This is a bicycle, the simplest two\-wheeler of all: no engine, just you\. Walk round it chapter by chapter to see how its frame, wheels, gears and brakes work together\. Drag anywhere to turn the view\.

It is a generic everyday hybrid bike, not one brand's model\.

### 2. Two strong triangles

The frame is called a diamond frame: a front triangle and a rear triangle that share the seat tube\. A triangle cannot be squashed out of shape without bending its sides, so thin, light tubes can carry a grown\-up rider\.

Frames are usually aluminium or steel; most racing bikes use carbon fibre\.

### 3. Wheels hung on spokes

Each wheel is a thin rim held perfectly round by 32 tight steel spokes\. The spokes pull rather than push, so the hub really hangs from the rim above it\. The name 700c sounds like 700 mm, but the rim measures 622 mm across\.

With a 28 mm tyre the whole wheel stands about 68 cm tall\.

### 4. Pedal power and gears

Your feet turn the 170 mm cranks and the chainring\. The chain carries that pull back to the rear wheel, the only wheel that is driven\. The derailleur moves the chain across nine sprockets: a big one makes hills easier, a small one goes faster on the flat\.

The two little jockey wheels in the derailleur keep the chain tight\.

### 5. Disc brakes

Squeeze a lever and two pads inside the calliper grip a steel disc, called a rotor, bolted to the hub\. Rubbing turns the bike's speed into a little heat\. Discs keep working well in the rain; many bikes use rim brakes that squeeze the rim instead\.

### 6. Steering that steadies itself

The steering axis leans back at about 72 degrees and the fork bends forward\. The tyre touches the ground a little behind where that axis meets the floor\. This gap, called trail, makes the front wheel want to roll straight, which helps the bike balance\.

To turn, riders briefly steer the other way, then lean into the curve\.

### 7. Metals for each job

Rims, hubs and cranks are usually aluminium: light and slow to rust\. The chain, sprockets and spokes are steel, because they must be hard\-wearing and strong\. Try the two finishes for the aluminium parts\.

### 8. Hidden bearings

Look through the frame\. Rings of steel balls, called bearings, let the wheels, the cranks and the steering turn with very little rubbing\. The rear brake hose and gear cable \(orange here\) run hidden inside the tubes\.

### 9. Pick a colour

Tap a chip on the colour board to repaint the frame and fork: Signal Red, Ocean Blue, Meadow Green, Sunflower Yellow or Graphite\.