Radio Quartz BMX Race Frame - Pro XL 21.25" TT Metallic Copper. Brand new for this season the Quartz frame is a x2 World Championship winning super light alloy race frame. Taking our track proven Helium frame as a base we upgraded the frame to use our new Paradigm 6061-T6 hydroformed superior tubing to shed a considerable amount of weight compared to the Helium frame. The Quartz also uses our new forged dropout design which allows it to be fully disc-brake compatible when used with our Helium Disc Brake Mount.