Encyclingpedia: BMX Bikes

BMX Bike Overview

Bicycle Motocross (BMX) bikes are the smallest bikes used in competitive cycling with 20” wheels and relatively small frames. BMX bikes are especially durable given the nature of the sport which includes high speeds, frequent jumps and occasional crashes. The small, compact frame contributes to the BMX bike’s durability and allows riders to sneak into tight spaces when entering a tight corner eight riders wide. Because of the small frame size and the relative simplicity, BMX bikes are traditionally the first bike a child rides, making BMX one of the most family-friendly disciplines of cycling.

BMX bikes have wide, knobby tires mounted on 20” rims which provide maximum traction on a dirt racing surface.

Like track bikes, BMX bikes generally have a single gear. The gear ratio (the size of the front chainring compared to the rear one) determines the amount of resistance on a pedalstroke. Gear selection is paramount as a rider needs to start fast once the gate drops but also needs to achieve and maintain maximum speed.

A BMX bike only has one rear brake with the brake lever typically mounted on the right handlebar.

SRM Powermeters and Powercontrols are also mounted on BMX bikes to determine the amount of power a rider generates. The devices serve as a vital training tool by providing the athlete with valuable scientific data.