I own a K1100 LT (< left) and I am now using a Michelin Pilot Road 4 in the rear. It is a 150/70/17. The OEM size is 140/80/17. I got 11,000 miles out of the rear Pilot Road 2 that was recently replaced. It still had another 1,000 miles remaining but it was replaced because of cupping...my fault, it was irritating rounding corners with the thumping. I was riding with 38 psi when it should have been 42 psi.
In the front I have a Michelin Pilot road 2 mounted in the stock size of 110/80/18. In a few weeks I will be replacing it with a Pilot Road 4 in size 120/70/18...in the GT version. The GT is the same except that it has a reinforced casing which is for heavier bikes. (The 110/80/18 size is not being made in the PR4.)
These are radial tires that handle well and are great in rain and cold too. They have a 2 part tread. A harder tread in the center for mileage and a stickier tread on the sides for, well, you know. They are slightly expensive but they get high mileage and offer up great handling. Well worth the price IMO.