Guide to BMX Bikes

Just how much bike do you need?
That depends on your weight, and what you are going to do with/to the bike.

We distinguish between six levels of quality for BMX bikes based on the frame materials and components:

  • Beginner
    These bikes are made with high-ten steel* frames (high carbon steel), have one-piece cranks, and basic tires. These are not suitable for jumping.
  • Entry Level
    The major upgrade here is a three-piece crank. These stronger cranks enable jumping, but the wheels are not strong enough for aggressive stunt work.
  • Level 1
    Starting to get serious, but still for lighter, tamer riders. These bikes will have some chrome-moly steel tubing*, higher quality hub bearings, integrated headset (steering bearing), but still single-wall rims—therefore not suitable for aggressive stunt work.
  • Level 2
    Three tubes Chrome-Moly frame, double-wall rear rim, all sealed bearings. This is the minimum strength required for real stunt work. This is especially important for larger riders.
  • Level 3
    100% Chrome-Moly frame, Chrome-Moly handlebars, double-wall front and rear rims, all sealed bearings.
  • Signature/Pro
    These are typically the exact specifications of the pro rider whose name appears on the bike. Expect all of the features of a level 3, but with parts often sold as upgrades.

There are no official weight limits. Even the strongest parts can be destroyed. Warranties do not cover anything that is bent. It is more cost effective to spend more for a complete bike that has at least everything you need, than to replace with stronger parts later.

There are two possible mind sets in play when doing stunts:
1) Let me see how bad I can be to this bike before it breaks, and
2) Let me see how radical I can get without hurting the bike.
One destroys the bike, while the other is much less likely to.

* There are many versions of steel. Those found in bicycles are typically the following:
Mild steel: used in cheap bikes.
High-ten (high carbon) steel: significantly stronger, but by no means as strong as it gets. This is used in entry-level bike store quality bikes.
Chrome-Moly (Chromium-Molybdenum or CroMo) steel: very strong. With Chrome-Moly, compared to high-ten, the designer has the option of making the frame stronger with the same weight, lighter with the same strength, or anywhere in between. Typically, they aim for more strength with moderate weight reduction.

What size bike do you need?

It's not just the wheel size, it's the top tube length (the distance from the seat to the handlebars). While personal preference can override this chart, here are the normal sizes for BMX bikes with 20" wheels.

18.5" for riders 4' 3" - 4' 6"

19.5" for riders 4' 5" - 4' 8"

20.0" for riders 4' 9" - 4' 11"

20.3" for riders 5' 0" - 5' 3"

20.5" for riders 5' 3" - 5' 9"

20.8" for riders 5' 8" - 5' 10"

21.0" for riders 5' 9" and taller

This sizing is to facilitate proper weight distribution and handling. It is reasonable to assume that some younger riders will grow into a larger bike by the time they are adventurous enough to be doing any real stunts. However, if the rider is already doing stunts, they will need a bike that fits right now.

With adult bikes that come in multiple sizes of seat tubes (and top tubes), the top tube measurement is called "effective top tube length" and is measured as if the top tube were parallel to the ground. With BMX bikes, where all tube slant by approximately the same amount, the measurement is simplified and is the length of the actual tube, measured from the center of the head tube to the center of the seat tube.

Different Types of BMX Bikes

By far, the most popular style of BMX bikes today are «freestyle» bikes. These are designed to handle well when doing stunts. They are built with extra strength compared to race bikes.

The original BMX bikes were designed for closed loop, banked turn, dirt track racing where there are typically eight racers on the track per moto (heat). «Race» bikes are built for speed and are much lighter than freestyle bikes.

A style of BMX that was popular in the 1980s is known as «flat land». The stunts done with these bikes look like gymnastics with the bicycle as the apparatus. No jumps, track, or obstacles are required, just a flat surface.