Classic is back! SONIC BOOM is a high performance dirt jump frame. When you ride into the dirt jump, to enhance supportability from is necessary. It made of Aluminum that's rigid and responsive but lightweight, which built for doing stunts, tricks and go on rampaging. It designed with all the new up to date dirt jump features such as a tapered head tube and super-short chain stay & wheelbase length. Its rear dropouts sit on horizontal sliding system for easy chain tension and also adjust chainstay length.