After reading this BMX bike size guide you will be better informed on how to choose the BMX bike that fits best your body, your wallet, and your riding style.
My first bike 27 years ago was a second-hand GT BMX blue bike, the fun and good memories that I had with it are priceless to me. Jumping stairs and sometimes pissing off some people but man it was the first time I felt powerful and free.
The nature of BMX is wild and the quality of the bike you’ll get will determine how much punishment your bike will be able to handle, in this guide we are also going to look into the materials that add the most to the durability of your BMX bike for when the moment comes, you’ll know exactly what you are getting.
Table of Contents
- BMX Bike size guide: First steps!
- How to choose the right BMX bike size for you?
- What is your BMX riding style?
- Know what you are getting: BMX Materials and Components
- The finish line
BMX Bike size guide: First steps!
What is a BMX bike?
BMX is the acronym for bicycle motocross, it all started back in the 70s in the golden state of California when people thought that taking their bikes to a motocross trail could be fun and hell they were right!
Since then BMX has exploded into many different ”disciplines” or riding styles like park, race, and street. Naturally you’ll find BMXs built specifically for these purposes. If you have no idea of what I’m talking about don’t worry I will dig deeper into the riding styles and the components that make them different.
Purpose-built BMX bikes are no joke and they LOVE to be punished, flipped around, do railings, land on flat hard ground, they are the perfect mate for an X-sport lover. Of course, you’ll find different qualities and prices and you should be absolutely sure your BMX bike will handle whatever you want it to handle because a bike that breaks when landing a backflip is a pretty bad investment.
How to choose the right BMX bike size for you?
BMX bikes are sized differently than other types of bikes, they usually have the same size of the frame. The things that really change its size are top tube length and wheel size and they are sized by height. So make sure to measure your height correctly and always check for the manufacturer-specific size chart.
The most popular size for BMX bikes is 20”. You can find it with different top tube lengths, the sizes range from 12” to 24” and they are normally divided into two categories: Freestyle and Race. Let’s look at this BMX bike size chart that will point us in the right direction when choosing our size.
BMX Bike size chart
| Height | Race Size | Freestyle Wheel Size | Top Tube Lenght |
|---|---|---|---|
| 3’3″ – 4′ 99cm – 122cm | Micro | 12″ – 16″ | 15″ – 16.5″ |
| 4′ – 4’6″ 122cm – 137cm | Mini | 16″ – 18″ | 16″ – 17.5″ |
| 4’6″ – 4’10” 137cm – 147cm | Junior | 18″ – 20″ | 17″ – 18.5″ |
| 4’8″ – 5’4″ 142cm – 162cm | Expert | 20″ | 18.5″ – 19.5″ |
| 5’4″ – 5’10” 162cm – 178cm | Pro | 20″ | 20″ – 20.5″ |
| 5’8″ – 6′ 172cm – 180cm | Pro XL | 20″ | 20.75″ – 21.25″ |
| 6′ and up 180cm and up | Pro XXL | 20″ | 21.25″ – 22″ |
What is your BMX riding style?
Picking the bike according to the style you are going to be riding will give you the best performance possible as they are designed and built differently for each style. So let’s check out the kind of riding styles and their most important features.
- Park style BMX bike: Also known as freestyle bikes, they have shorter top tubes and chainstays with steeper headtube angles. These features make them easier to handle while you are at the skatepark having fun, dropping in, rolling or jumping for example.
- Street or Flatland BMX bike: Pretty sure you have seen someone doing a sort of breakdance with its bike, well this is the style you need to look for if that’s your thing. Normally they are lighter and all the tubing tends to be smaller to improve control and balance.
- Race style BMX bike: They are built for speeding and to improve stability and responsiveness, they have longer top tubes or wheelbase and slack head tube angles.
Know what you are getting: BMX Materials and Components
In the process of choosing your BMX, you will stumble across different terms of which components and materials are described. Normally the price is a good indicator of quality components and frame material but it’s always handy to know what you are getting!
Frame materials
These are the top 3 materials used to build BMX bike frames:
- Hi-Ten: Stronger than mild steel and the most affordable material
- Cro-Mo: The most widely used material on BMX bikes is stronger than Hi-Ten without mounting too much the cost.
- Heat treated: The strongest of the three materials and you’ll find it on high-end BMX bikes.
Rims
First of all, let’s look at the rim walls, you can find single, double, or triple wall rims. These walls are found on the interior of the rims. The most common and affordable are the single-wall rims. As you add more walls the cost mounts but also the durability, weight, and strength of the rims themselves.
Three-wall rims are pretty rare as they are expensive and heavy, I personally prefer double-walled rims as they are the most balanced out of the three in terms of cost and durability.
Another difference you’ll find with rims are the numbers of holes or spokes they have, they come with:
- 36 holes rims: The most common and affordable option, they are light and provide good resistance
- 48 holes rims: At first BMX bikes were made by default with 48 spokes, now that has changed and 48 holes rims are a bit pricier and heavier than their 36 counterparts. If your plan is to do big drops these are your way to go.
And finally, the ways rims are sealed together and they can be pinned or welded. Most usually you’ll find pinned rims on single-walled rims. Of course, this is the affordable option, but they tend to break as time passes. Welded rims are the best choice in terms of quality and durability.
The finish line
Knowing your measurement, your riding style, and the materials you are looking for will make your choice easier and wiser.
BMX bikes are highly customizable and you can change pretty much everything, cranks, crank arms, pedals, seat, handlebar, hubs, and so on. The choice of these components will be based on personal preferences or to improve performance, they are a big topic on themselves that we will cover later on!
BMX safety equipment is a must, I will not recommend going out on any kind of bike without equipment and you should take extra care in your protection when riding BMX bikes.
Want to check out other types of bike sizing guides? Go ahead!