I have had about 10 flats, in the last 2 or so months after getting a DP18 wheel rear wheel. I have replaced my tire, rim tape (velox), etc. No luck. A few of these flats have comes from "nothing". Last night I was hanging out in my living room watching TV and all of a sudden I hear my tube deflate. What could cause this? I'd say 3-4 out of the 10 flats have been like this.