I need new tires for my 1977 kz650. I used to have a TL1000s and then a 2006 ZX10R which were used both for spirited driving and track days. I know that the kz650 is a totally different type of bike and I ride it quite relaxed, but I would really like some tires that would at least somewhat support spirited driving. It is currently fitted with 140/90-16 Michelin Commander II in the rear which seems to be a difficult size to find anything other than pure cruiser tires? The options I have found are: Commander II + III Shinko 777 Avon Cobra Chrome Dunlop D404, American Elite, 491, K527 Metzeler ME888 So as far as I can see "only" very cruiser-oriented tires. I would really like to keep the size as I like the look, but I am also considering going down a size to 130/90-16 as they at least have Metzeler Roadtec 01 which seems to be a more sporty tire that the ones listed above. My main problem is that I have no real experience with all the tires listed in the 140-list, but I can only say that my current Commander II is almost hard as rock and I am not in any way looking for longevity in a tire. So any input would be highly appreciated. Also if I have overlooked a possible tire in the 140-list that could fulfil my needs.