I've got a 1.95" on the back that's a hybrid tread, but I might need to see if I can find a 2.1" more street-type tire I suppose. I was looking at these the other day (same width as current, just liked the tread design):
Amazon.com: Kenda Kross Plus Front/Rear Slick XC Tire, 26 x 1.95", Pair Of Tires !: Sports & Outdoors
I've been getting that level of depression on the roller, too. Frustrating.