I haven't seen many comments in this thread for the old 2V bikes. Bias ply tires are getting somewhat scarce, and I don't see any radials in the correct or even close to correct sizes.
On my 1987 2V K100RS, I am running Michelin Pilot Activs in the factory sizes. Normally I don't get hung up on brand names, but I have to say that I sure like Michelins, they always seem to have a wonderful "soft" and compliant feel about them. The Pilot Activ looks like it was made for the bike and though they are still bias ply tires, handling is much improved over the Dunlop Spitfires that were on the bike when I bought it. I like the Michelins well enough that I put a set on my /5, too.
Looks like I will be getting about 6000 miles out of this set of Pilot Activs. I ride at a medium fast pace, not "racetrack" fast, but I don't slow down much for corners, and I use all of the tire. Both tires have worn quite evenly and for once, it looks like I will be wearing out the front before of the rear. The tires have stayed pretty consistent and solid, with little or no cupping of the front tire. In the last few hundred miles, the front has started to feel hard and just a bit greasy in the turns, though it isn't down to the wear bars yet. Time to swap it out. I'll get a few hundred more out of the rear.