RCM-SP-1039 1039 - 2.2mm Stiff Weave Carbon Chassis (SP1-F) (Option)Optional 2. 2mm Stiff Weave Carbon Chassis for RC MAKER SP1 F This stiff weave chassis reduces flex substantially on the standard carbon chassis (1033). This is suggested for medium high traction asphalt, and medium to high traction carpet conditions. On high traction carpet, we also strongly suggest using all screws in the motor mount, and the T brace with all screws installed! Manufactured from 2. 2mm Stiff Weave Carbon Fiber RCM SP 1039 Includes: