esti f (plural estis) 1  Alternative form of. â 2 estiâ in le TrÃ©sor de la langue franÃ§aise informatisÃ© (The Digitized Treasury of the French Language).
Frame dragging is a theory which says that space is elastic, and particles in it will exchange energy with it. In the scientific world, elastic means that when you apply a certain amount of force to an object (which will cause it to bend) and then remove the force, the object will return to its original shape and energy state.
The twin spar or twin beam frame is one of the most commonly used frames among sportbikes. If you've owned a GSXR, YZF, CBR or ZX of the last 10 years you've ridden a twin spar. They are very rigid, and strong frames.