So whats with all the sizes?

Let’s breakdown the various names and terms of bike sizes in the BMX race world and try to guide you to the right decision. There’s a few points to consider when you look at height/age charts online, one of them being that an “Expertâ€� sized complete bike from one brand might be a slightly bigger (or smaller) than an “Expert'' sized bike from another. Not massively different, but enough to make a difference to how a rider would feel on it. 

BMX race bike sizes are named according to their frame size (most commonly the top-tube length) and tyre size, but there’s not an international or industry standard, and what one company might call a mini-micro, another might call just micro. A Pro XL would typically have a 21 inch top-tube, or a 20.75 inch top-tube.

 Confused? What’s a top-tube? The chart below outlines a typical frame specs and you can see what we’re referring to with top-tube length. This measurement will set the basic architecture of the rest of the frame/bike design, with parts like handlebars and cranks falling into line with a particular company’s specifications of what they feel would suit a rider choosing their “expertâ€� size bike (for example). Let’s take a look at an example frame dimension sheet, then a complete bike spec sheet that ties it all together.