Buyer's Guide Topics

Jargon Buster

There's a lot of jargon used in the bike industry.  In most cases it's useful for accurately describing the bikes or components; in some cases it's used to bamboozle or even mislead you.  In this guide we try to explain some of the most common terms or phrases, so you can find your way around.

Be Aware!  Wherever you buy your bike from, product information is ordinarily provided in the form of specifications (specs).  As a general rule, more expensive bicycles will come with accurate, detailed technical specs, whilst cheaper bikes (particularly those selling below £150) will either have no specs, or will be littered with nonsense words.  Be an informed customer, and know what you're buying!

This guide is split into 2 sections:

1. Bike Components - identification of the major parts
2. Component Guide - descriptions of the various components

1. Bike Components - identification of the major parts

There are several high-tech components on a modern bicycle.  The two bikes below give an overview of the major parts.

2. Component Guide - descriptions of the various components

Frame

The frame is the backbone of the bicycle.  It defines the basic nature of the bike through the frame geometry (the angles and lengths of the frame tubes).

Headset

The headset connects the fork to the frame and allows the movement for steering.  They come in 3 different types, as well as a variety of sizes, so it is important to select the right one.

Threaded headsets are used with quill stems, usually on road bikes, but they are being superceded by threadless or Aheadsets.

Threadless headsets or Aheadsets are found on almost all mountain bikes and most road bikes.

Integrated headsets offer lower weight and fewer parts than other headsets, but require special frames.

Threaded Headset

Threadless Headset or Aheadset

Integrated Headset

Stem

The stem simply connects the handlebars to the fork.

Brakes (Rim Brakes)

Calliper brakes are used on most road racing bikes because they offer excellent, graduated stopping power.

V brakes (or linear pull brakes) are used on almost all new mountain bikes, commuter bikes, recreational bikes and touring bikes.  They are powerful and reliable, particularly when made of high quality aluminium alloy.

Cantilever brakes are found on older and cheaper mountain bikes.  They have been almost universally superseded by V brakes, but are still used on some touring and mountain bikes because of their simplicity.

Calliper Brake

V Brake

Cantilever Brake

Disc and Drum/Hub Brakes

Disc brakes are slightly heavier than rim brakes, but they can offer significant advantages: they are much less affected by water and mud, do not require a perfectly true rim, and require much less maintenance.  They are particularly suitable for mountain bikes where braking can be severe, and the rim is often covered in mud.  Disc brakes can be mechanical (operated by a steel cable) or hydraulic.  Hydraulic disc brakes are extremely efficient, reliable and maintenance free.

Drum or Hub brakes are heavy and complicated, but require very little maintenance because they're inside the hub and not exposed to the elements.  They are generally less effective than rim or disc brakes and are usually found on commuter bikes.

Disc Brake

Hub Brake

Fork (and Suspension Fork)

Road bike forks are typically aluminium or carbon fibre, with carbon fibre becoming increasingly popular because of its light weight and excellent ability to soak up road shocks.

Suspension forks are mostly found on mountain bikes, but they are becoming increasingly common on commuter and recreation bikes.  A good suspension fork will be light, and soak up bumps without compromising control and pedalling effort.  Different suspension forks offer different lengths of travel: forks for serious downhill bikes will offer over 200mm travel, while those for cross country trail riding usually offer around 80-100mm.  More travel means more weight and less efficiency on the up hill.

Downhill Suspension Fork

Cross Country Suspension Fork

Rims

Good quality bikes are usually fitted with durable, aluminium rims.  Cheaper steel rims are heavier and far more prone to buckling.  Brakes work far better on aluminium rims than steel rims.

Spokes

Spokes attach the rim to the hubs.  Spokes come in different lengths, shapes and thicknesses.  Chrome-plated steel spokes are cheap and prone to rust, galvanised steel spokes are stronger and rustless, and stainless steel spokes are the strongest but most expensive.

Hubs

The hub is at the centre of the wheel and turns on ball bearings around an axle.  High quality hubs use sealed bearings and are fitted with a quick-release lever for easily removing the wheel from the bicycle.

Front Hub

Crankset

The crankset consists of the crank-arms (or cranks) and chainrings.  Good quality cranks are made of lightweight aluminium.

Crankset

The cranks are connected to each through the bottom bracket, the unit containing the axle joining the two pedal cranks together.   The bottom bracket bears enormous stresses - most modern bottom brackets are sealed units which are much more durable and maintenance free.

Derailleurs

The front derailleur shifts the chain from one chainring to another; the rear derailleur shifts the chain up and down the gears on the cassette.  Good quality aluminium derailleurs will be lighter and far more responsive than cheaper versions.  However they need to be adjusted correctly and like all moving components do require regular maintenance.

Front Derailleur

Rear Derailleur

Chain

Bicycle chains have to withstand enormous forces - mechanically it is one of the hardest working parts of the bike.  Good maintenance (regular lubrication) will greatly improve the life of the chain.  Typically, chains stretch as the chainrings and gears wear down, so replacing a chain or chainring often involves replacing the entire drivetrain.

Cassette (or cluster, or freewheel)

The cassette is the selection of gears or sprockets mounted on the freewheel body or directly onto the rear hub.

Cassette

Tyres

Tyres for road use are lightweight, narrow and smooth, whilst off-road tyres like those found on mountain bikes are much fatter, heavier and knobbled to grip on muddy or sandy surfaces. The fastest road racers have very small, high pressure tyres, which produce a very hard ride. The fatter tyres found on recreational bikes make for a more comfortable, but slower ride.