Okay so I'm stumped right now with my rear tire. I've put less than 100 miles on my bike since I've had it. I go out to ride last weekend and my rear is flat. I check for nails, holes, and the cap. Nothing wrong, I take it to the dealer and they check it too with no problem. They air it up and I ride around, keeps air for the next day and a half fine. Park it and today I go out and it's flat again. Is there something I'm missing? Did the dealer miss something? What should my next plan of action be..?