How to choose the size of your fixie / singlespeed bike frame?

When buying a new bike or frame, there always comes the fundamental question of which size to choose.

The decisive criterion is the size of the crotch , the size of the cyclist is indicative and provides a benchmark by proportionality.

For an urban bike, an adult should find their frame size by applying the formula:
Frame size = Inseam measurement in cm x 0.66

The bike is not just a calculation, the frame size given is indicative, it is better to try to know your frame size.

This gives us the following table:

Frame size is actually the measurement from the bottom bracket spindle to the end of the seat tube .

The rest of the tubes of the bicycle are proportional to the latter, so we can refer to the size of the seat tube to choose a bicycle adapted to its size.