When i reach ca 55-100+ kph i get a horrible vibration and sound, it seems to be speed related not rpm because i dont feel it When starting from 0 kph only after gettin up to speed. V ring pulled, exaust plugg also but thats it. Im thinking that the drive belt might be fluddering and I need a stiffer one? But i resantly put a new exaust on (Tecnigas silent pro 030725011) and heard a ruomor that I might get chockwaves bouncing back because new one dont have that pice of pipe on the bend close to the cylinder? Im a bit lost to whats causing the vibration?