Zero Gravity Double Bubble Windscreen - Smoke The Zero Gravity Double Bubble has changed the face of the sportbike industry. This innovative "bubble within a bubble" concept was pioneered by Zero Gravity and has pushed modern day race bikes to their peak performance level. From our first inception of a performance windscreen the Double Bubble, is Zero Gravity's version of the now popular "stepped profile" design, pioneered by Zero Gravity Racing in the mid-90's. Sculpted to the sport bike's distinctive futuristic lines, the Zero Gravity Double Bubble enhances the bike's race look while providing added aerodynamics. Image is for reference only.