Our Guide to Buying: BMX Bikes

What are BMX Bikes?

In a nutshell

There are two main types of BMX bikes; race and freestyle. Race bikes will be built with the lightest weight parts and will typically feature a longer wheelbase to be more stable at high speeds and whilst in the air. Freestyle bikes are built of more sturdy materials and are often engineered to be more manoeuvrable for performing tricks and stunts. It is important to consider how the BMX will be used in order to choose between a race bike and a freestyle bike.

Breaking down the Jargon

So you're looking to buy a bmx bike? Take a look through some of the common BMX terms so that you know exactly what you want when you get down to buying.

What are BMX bike frames made of?

The frame is the key component to any bike that will determine how it will handle and how well the bike will fit a rider. Freestyle BMX frames will be made of steel, chosen for its strength and compliance. Cheaper bikes will be made with high tensile steel or 'Hi-Ten' steel, but will not be as strong or as light as those frames which are made with Chromoly steel, sometimes referred to as '4130' or 'CroMo'. Race BMX Frames will often be made from aluminium, as it is light and stiff and perfect for the quick acceleration and fast handling of a BMX race. Aluminium frames are not recommended for freestyle use as they are more brittle and more prone to damage.

Forks

Forks hold the front wheel and extend through the frame to connect to the handlebars. Forks are important as they work alongside the frame to support the rider and so strength is equally important here. Many BMX forks will be made from the same steel as the frame and will be reinforced with thicker tubing and better welds to withstand harsh impacts.

How do BMX handlebars differ from normal bike handlebars?

BMX handlebars are one of the defining features of any BMX bike thanks to their very tall rise (the distance from the bottom of the handlebar to the top) and 'bucket' shape. Handlebars will often be wide for good control and also be made from steel. Many handlebars are 'butted', which means the tubing is varied in thickness throughout the handlebar for optimum strength in key stress points while maintaining a light weight.

What sizes are BMX bike wheels?

BMX wheels are often 20" in diameter, although it is possible to find BMX bikes with wheels anywhere between 12" and 24" to fit different riders more appropriately. The wheels' small size lends itself to manoeuvrability and strength. Often BMX wheels will have 36 spokes, far more than any type of bike, great for keeping the wheels true even after years of abuse.

Hubs

Hubs are the central part of the wheels, that house the bearings that enable the wheel to spin. Look for sealed bearings where possible for durability and a longer service life.

Rims

Rims are the outer most part of the wheel that the tyre is connected to. Rims will be made of aluminium and will be wide and strong. Some rims may be anodised, anodising is a process for chemically bonding a colour to metal components for a long lasting and hard wearing finish, enabling bright and bold colours to be used by manufacturers.

What are the differences between normal bike tyres and BMX tyres?

BMX tyres are often very wide and designed to run at high pressures to absorb all of the impacts that come with freestyle. Race BMX bikes will often come with slightly skinnier tyres as they will be faster and also less likely to land with such force as a freestyle bike.

What is the gearing/drivetrain of a BMX bike?

BMX bikes will have only one gear, often referred to as single-speed. This single gear requires little maintenance in comparison to the complex systems found on road and mountain bikes. Using a single gear means that the bike will be lighter. Often the gear ratio is chosen so that the bike will be easy to accelerate but also hold a high speed, a perfect all around solution. The drivetrain of a BMX bike consists of a bottom bracket, a single sprocket with an average of 26-28 teeth, and a chain that is designed to withstand high impact. Some riders may choose to have a sprocket guard to provide extra protection to the chain and sprocket.

Brakes

BMX brakes are simple in their design, but work effectively. some may come with a 'gyro' or 'detangler' fitted. This enables the user to spin the handlebars multiple times without the need to untangle the cable afterward. BMX bikes most commonly only have a rear brake, as the front brake isn’t required for most freestyle tricks. Riders that take to the streets to ride, may choose to remove their brakes entirely.

What are pegs?

Pegs are tubes that effectively extend the axles of the hubs, great for tricks like grinding or flatland.

What type of pedals and cranks do BMX bikes have?

BMX bike pedals are flat pedals made from either plastic or metal, to enable the rider to perform tricks by taking their feet off, and providing enough grip to secure their hard landings. BMX bike crank arms are the metal bar connected to the bottom bracket and the pedals. Not only are they used to create speed when pedalling, they are essential to ensure stability of the bike so that riders can carry out technical tricks