I hit a pretty big nail, and it took quite a bit to get it out. I checkd the tire for any more debris and then I placed a dollar bill where the hole was, but my first tube exploded. Honestly, I was in such a hurry to get back on time I thought I did the CO2 too fast. Then a SAG vehicle came up- laughed at my dollar- took it out and promptly blew up my second tube. Needless to say I was dnf- did not finish. The Sag group thought the shop may have sold me an incorrect tube for my tire. Any suggestions and also how can I tell what tube goes to my tire?