LDO, if the vibrations go away after about 85-90 k's, the most likely problem is wheel balance. If they come back at 160 kph, then you know it's wheel balance, though don't take this as permission to try & check. Look for evidence that a wheel weight is missing, they usually leave outlines on the rim. Dattosans problem happens when he unloads the drivetrain, thats why I suggested looking for loose nuts first. It took a long time for me to live down the shame, when it happened to me, mainly because I was stressing out about the uni's I'd just replaced being duds. None of my friends let me forget about it for a long time, until one of them did something stupid & it was his turn to suffer.