bmx frames for sale australia

Back Bone BMX stock a great range of the best BMX frames available. Freestyle BMX frames are durable, made from high grade 4130 Chromoly, making them light weight while still tough as nails. Often featuring double butted and heat-treated tubing, with gussets in areas to further increase strength. 


You'll find BMX frames for sale here that differ a lot in their dimensions, making each frame unique in the way they feel when riding. 

If you're scratching your head about what type of frame geometry you need, fear not - we're here to help.

bmx frame size geometry image

BMX frame sizing:

If you're unsure what the geometry means and what it does on a BMX frame, this handy guide is for you!

Top tube length: The distance measured from the center of the head tube, to the center of the seat tube. The top tube length is the only factor that comes into play when looking for a BMX frame size that suits your height, as it provides more room between your seat and handlebars.

Head tube angle: The angle of the head tube from the ground. Generally anywhere from 74° to 76°. The bigger the number, the steeper the head tube angle, which translates to faster steering. You will find steeper head tube angles on BMX frames that are catering towards street riding and quick movements, while mellower head tube angles allow for a more stable bike at higher speeds. 

Stand over height: The length of the seat tube, measured from the center of the bottom bracket, to the center of the top tube. The stand over height gives a BMX frame more stability by having more frame under your legs! A taller stand over can also help with tricks like barspins, as your seat is higher. On the contrary, a low standover will help move your legs over the frame for tricks like tailwhips.

Chainstay length: The length of the chainstay (bottom rear triangle tube), measured from the center of the bottom bracket to the dropout. Generally distances between 12.5 to 14.8 inches. This measurement affects being able to lift the front wheel off the ground, as well as ability to spin a BMX bike quickly, due to change of distance between the wheels. A shorter chainstay length comes at a cost of stability at faster speeds.

Bottom bracket height: The height of the center of the bottom bracket shell from the floor, measured based off a 20 inch wheel in the dropouts. Generally ranging from 11.3 - 11.8 inches. The bottom bracket height determines your center of gravity on the bike. A higher bottom bracket creates a lively feel BMX frame, while a lower bottom bracket makes it more stable.

Seat tube angle: The angle of the seat tube from the ground. Generally anywhere from 69°to 72°. The smaller the number, the further back the seat would be, giving you the feel of a larger BMX frame without having to make any other measurement larger. 

Back Bone BMX sends BMX frames Australia wide with free shipping.