USA custom built frames to your specifications. All USA frames are: 156 wall thickness D.O.M. 100% TIG welded. 100% welded in rotating fixture. motor mount, side plates, and axle blocks are made in C&C machine. tubing sizes available: 1"/ 1.25" / 1.5" for frame. 2" available for downtube (curved or straight). pointed or standard (rounded) swingarm ends and downtube end.