Measure the frame and pick the right size of a bike

You're not buying a new bike everyday, so it is vital to find one that will match you completelly. The basic criteria is proper size. How is the frame measured and what else you have to think of while choosing? We'll explain further.

Frame size

Basically, you could just say that the size of bike frame is the length of seat tube.

We measure it from the center of a crankset to its end - where the saddle starts - divide the given length in cms by 2,54 and the result is the frame size in inches.

Video demonstration how to do it.

What bike size do you need?

Below, you can see a chart showing standard sizes of bike frames used by manufacturers.

Caution, these are just general parameters and there are differences between different bike types.

Shapes of bike frames

The rule of thumb that all the bike frames have basic - triangular - shape, is inaccurate for ages.

Nowadays, manufacturers invest huge amount of time and energy to develop specific geometry that constitutes each model. It can differ in angles, ratios and curvature of tubes, which fundamentally affect your comfort while biking. Therefore it is quite possible that bikes of the same size, but made by various manufacturers, can fit you differently.

What other parameters are essential?

Standover height

When buying a bike, beside knowing your height, you have to know length of your inside leg. That is related to standover height - the space that is between your groin and the frame while standing on your feet on a ground. Ideally, you should clear it by 2.5 - 5 cms. This comes in handy if you have to get of the bike suddenly.

Handlebar reach

Even more crucial parameter is the reach since you spend most of the time riding a bike holding the handlebars. This represents how well you can reach them while sitting on a bike. The length affects whether you sit more upright or stretched to the front.

It's also convenient to know the ratio between length of your torso and length of your legs - and determine whether you have longer legs or torso. Bike with ideal standover height can provide for a long-legged person a stem too far to reach so the person has to be too streched, while someone with long torso would have the handlebars just too close to the body and would be cramped.

Bike type

While on an urban bike you sit more upright, on a"road bike" you have to get yourself into the aerodynamic position.

When it comes to mountain bikes, the overall feeling depends on wheel size. MTB frame with 26" wheels have different geometry than the one with 29" wheels.

Awhole different category are BMX bikes, where the frame geometry is more strict and the sizes have different numbering system.

In a size table I'm somewhere in between - what now?

If you're in between two sizes in a table of a manufacturer's particular bike model, than both sizes should fit you.

However, this is exactly when the reach and ratio between the length of your legs and torso will be decisive.

If your torso is longer than the average, go for a larger-sized bike.

Otherwise, when your legs are longer than the average, opt for a smaller bike.

The overall comfort of riding a bike can be achieved by adjusting the saddle position, extending or contracting stem or widening of handlebars. However, you just won't change the size of the frame, thus the right choice of it is vital.

Don't underestimate bike care

Now that you know what you have to consider, choose your bike according to your needs and in the right size. If you worry that your new beloved machine might get a scratch or two, you can get frame protection.