I ride a cyclocross about 50 miles a week. About half of the mileage is spent on roads, the other half on single track trails. In the space of 3 weeks I have had the tubes pop 5 times. Once the back tube popped while riding on the road near my house. The other four occurred while the bike was hanging in my apartment.
I have double checked the interior and exterior of the tires for debris or objects and found none. I ensured tires were inflated to proper pressure and that the rim guard strips were in the correct place. I purchased the bike about a month ago from the neighborhood bike shop.
Is there anything I am missing? My current hypothesis is that the tubes degraded in the shop and spring leaks due to age. If that is the case, is it proper to ask the shop to replace the tubes with new ones?
Edit: August 2016
Hundreds of miles later on the same tires, rims, rim tape I have not had a single flat. I replaced the problematic tubes and tried to hold all other variables consistent. I was not able to determine the cause of the problems but it does appear the tubes that came installed from the bike shop were more brittle than expected. This could have been due to shop storage. Extended exposure to heat or light can weaken butyl tubes despite being more resilient to weathering and attack than natural rubber.