My Floride S has a very small shudder felt through your backside perhaps every 4th or 5th wheel rotation. It feels to be in the rear. It is more pronounced at higher speeds. Not there at all at slow speed say 60 kph. If it was a tyre or rim surely it would be there continuosly. My tyres are 14 years old and the front two were out of round and have just been replaced. Yes, I am about to order a full set of Michelins from UK. But I'd like to find the shudder before replacing the whole set.