HOW TO CHOOSE YOUR FIRST BMX ?

Having a bike that fits is a logical thing... In BMX freestyle, it's really important to progress safely. It's all about doing tricks with the bike, turning it one way and then the other. It requires a lot of agility, and with the right bike it's much easier to steer it in all directions. 

When you are a child, the ramps seem big and insurmountable. The bike feels heavy and big too. That's why BMX Freestyle brands offer BMX bikes that are suitable even for the smallest of riders. 

In order to know which size to choose, you can first take into account two easily visible criteria: the length of the top tube and the size of the wheels (in inches) When we talk about the Top Tube, we are referring to the top tube on the frame, the one that joins the steering column and the seat clamp. This size is used as a reference to find the right bike with the right frame geometry. 

Here is a table showing the length of the top tube and the size of the wheels, according to your height in CM.

By following this chart, you can find a suitable size. To quickly find a size range that matches your height. Measure yourself, and find your size range in the left column. Then follow the line to the right of the chart to find all the information you need to find the right size BMX FREESTYLE. 

* You can go to the catalogue on our website, and filter the products using your criteria previously found using this table. - Click here to view 

THE GEOMETRY OF THE BIKE 

For those who want to choose a BMX bike even more carefully. 

You should know that BMX can be ridden in many ways, on many different terrains. Depending on the use, whether it is in a skatepark, on the street or in a dirt bike, the geometry of the frame is a criterion to be taken into account. After reading about the TopTube, we will look at the different lengths and measurements on a frame. 

This drawing below will help you to understand where the different lengths and geometries of the frame lie. 

Let's look at the important points to consider when choosing a frame geometry for BMX FREESTYLE riding.

SKATEPARK RIDING

You like doing transitions, doing tricks at the top of the quarter. 

For this you need a responsive and easy bike. The criterion to take into account in this case is the "Chainstay". The length of your chainstay will determine 80% of the responsiveness of your bike.

It's very simple: shorter chainstays = more responsiveness.

Measure B on the drawing below shows you where this length is on a frame. To understand why this measurement affects the responsiveness of the bike, you have to assume that you have your feet flat on your crankset. Shorter chainstays allow the rear wheel axle to be as close to your rear foot as possible. This makes it easier to push your frame in one direction and then the other. 

So with this information you can, depending on your height range, choose a geometry with rather short chainstays. You can compare, and find the one that you think is the most responsive. Another point that can be interesting to take into account is the "Standover". This is the length of your seat tube. The measurement F on the drawing. 

This length also allows you to see if the bike will be higher or lower between your legs. Remember that we are talking about a skatepark type of use, and that you should favour the easy to handle side. We take an example of a trick that requires you to put your leg over the frame, it will be easier to do this movement with a shorter seat tube (Smaller Standover). 

These are the two important criteria for finding the right geometry for a skatepark.

STREET RIDING

In street riding, it's all about balance and stability. You want a bike that is stable, manoeuvrable and makes the balance point easily accessible. Street riding requires a little more resistance to shocks and difficult landings. Bikes and frames are generally heavier for greater strength. Let's look at some of the important criteria to consider when finding a geometry that is suitable for urban street riding 

The length of the rear chainstays should be shorter to facilitate rotation. As for a Skatepark use, it is preferable to have a bike that is easy to handle and to steer. 

Another criterion that makes steering easier is the angle of the head tube. (Measure C in the diagram). Depending on the frame, the difference is rather small but is very noticeable. A frame with 75,5° will be a very responsive and nervous frame. Optimal for street riding. The higher the angle, the more responsive and easier to steer. It also makes Nose Manuals easier. Starting from a range of 75.2° to 75.6° - you will get a really easy to steer frame. 

Bottom bracket height. This length will affect stability and the ease of finding the balance point on the rear wheel.

To find the balance point quickly, simply shorten the distance to the balance point. To do this, it is best to have a higher bottom bracket. 

If your bottom bracket is higher with both wheels on the ground, the distance to the balance point will be shorter and therefore easier to reach. If you have a lower bottom bracket, your centre of gravity will be lower, so the distance to the balance point will be longer and therefore more difficult to reach. 

The case height measurements do not vary dramatically. 

Let's assume that a 11.5" height is preferable for Skatepark or Dirt use, the case is rather low, to optimize stability at high speed. For Street, you can choose a height higher than 11,5" to get an easy geometry for balancing games. 

By taking into account the two measurements above, you can easily find an optimized geometry for the Street (urban use).

DIRT RIDING

This sport is considered a whole discipline in its own right. Dirt riding consists of a series of jumps over bumps. Bumps that can be very big.

To optimise the bike's behavior in this discipline, we need a bike that can go fast without moving too much. We are looking for something stable. For this we will use the principle of bottom bracket height, chainstay length and head tube angle. These three criteria are key to finding the perfect geometry for dirt riding.

A little physics on the centre of gravity. Like in Formula 1, cars are very low to stay as stable as possible at high speeds. On a BMX frame it's the same principle. The bottom bracket should be lower, in order to keep a stable behavior at high speed. 

A frame with a bottom bracket around 11.5" is considered a stable frame.

To increase stability and comfort in the air, you can choose a longer chainstay length. The bike will be more stable in the air, if not less manoeuvrable.

The head tube angle can also change the behavior of the bike in Dirt. In order to have a frame with stable geometry, the head tube angle should be lower. We recommend a head tube angle between 74° and 75° to optimise the bike's behavior. 

To sum up, dirt biking requires a stable enough behavior to be able to jump with confidence. To achieve this, longer chainstays, a lower bottom bracket to lower the centre of gravity, and if possible, a lower head angle to have a larger caster angle.

NOTE: 

We remind you that there are no formal rules on bike geometries according to use. This is for the sole purpose of advising you on the choice of your first bike. 

If you have any questions regarding the choice of your first bike, you can contact our sales department by phone or email.