I have a pair of Michelin Pilot Road 2 on my R1100RT. While doing routine maintenance I just noticed, and was much surprised, that there is a pronounced flat ridge that runs down the center of the front tire, all the way around. It is about 1 1/4 inch wide. I mean it is flat. There are definite edges to it all the way around, on both sides, where it drops off to the sidewalls. I can see it on the rear tire also, but not as pronounced because of the larger radius. These are "dual compound" tires. The previous owner put them on. He seemed to like the brand and the tire. Highly recommended them. But I don't know how many miles they have on them.
I can't remember ever seeing tires that didn't have a continuous curve all the way across, even when worn down. It doesn't seem like this would be the best design for a tire. Is this the way they should look, with the flat ribbon around them? Are they worn out when they get this way? I"m wondering if this isn't a large part of the reason the bikes seems less than rock solid at 70mph on the expressway. I will try to post a picture.