Yep, its most likely that fender extender you got on there.
Remove the back part of the fender and see if it has rubbed the tire.
Also, be sure and not tighten the screws too tight on the caliper covers.
If none of that has happened, I don't know what to tell you.
I removed my extender because it had rubbed. I was running the Michelin Pilot Activ on the front of my trike and it is thicker than the front tires for the two wheeler. It broke both my caliper covers in several places. I just put them back together with crazy glue. So far, so good.
The one on my two wheeler is the Bushtec extender with braces and it has not cracked anything in 94,000 miles.