Frames
Browse used BMX frames for sale from riders across the UK. The category covers bare frames only — heat-treated 4130 chromoly for street, park and dirt, aluminium and carbon for racing, and the short 18.5in to 19.5in geometry used for flatland. It is for riders replacing a cracked frame, changing geometry, or building a bike around wheels and cranks they already own.
How do I choose a BMX frame?
Start with top tube length, which sets the fit: 20.5in for shorter riders, 20.75in as the common adult size, 21in and above for taller riders or more room in the air. Then look at chainstay length, which decides how easily the front wheel comes up, and bottom bracket height, which changes how the bike feels when you are stood on the pedals. Freestyle frames and race frames sit at opposite ends of that range.
Which bottom bracket and headset standards should I check?
BMX frames use one of three bottom bracket shells: Mid at 41mm, Spanish at 37mm, and the older American at 51mm. Your existing cranks and bearings only fit one of them, so check the shell before you buy. Almost all modern frames use an integrated headset, and dropout slots are 14mm on freestyle frames and 10mm on race frames — that alone rules out swapping wheels between the two.
Should I buy a frame or a complete bike?
A bare frame is only cheaper if you already have a full set of parts to move over, since a complete bike includes wheels, cranks and bars for less than they cost separately. Buy the frame when you have snapped one and kept everything else, or when you want geometry that no complete is offered in.
What should I check on a used BMX frame?
Cracks form in the same places: the head tube and downtube junction, the gusset behind it, the seat stay bridge and the welds around the bottom bracket shell. Check the dropout slots for ovalling and the peg threads for burring, look inside the seat tube and bottom bracket shell for rust in a frame that has been ridden through winters, and lay the frame on a flat surface to check the rear end has not been pulled out of line.
What is a used BMX frame worth?
Full heat-treated chromoly with butted tubing, removable brake mounts and an integrated headset holds most of its value; a cheap gas-pipe frame is worth almost nothing second-hand. Grind marks on the chainstays and scratched paint are normal and priced in. Buy new if you want a warranty against a cracked head tube, because a used frame carries whatever fatigue its last owner put into it.