A Micro BMX race bike has 18 inch wheels, which is the perfect size first bike for your (really) young racer. How young can they start? As young as 3 years old! With a smaller wheel size, it means that these Micro race bikes are closer to the ground and super light, meaning they'll fly around the track. Sizing for these is quite specific, so if you're not sure if your sprocket rocket should be on a micro or a mini sized race bike, hit us up and we'll make sure you get your little racer on the right one.