Hey,

About 3 weeks ago I finally made the change from super-cheap $6 tires to Specialized Armadillos (700x23c) for my commuter bike. I was tired of the all too frequent flats I was getting on the debris-strewn road I have to take to work. The new tires have been great, no problems, no flats...until....

Yesterday I was at a slightly uphill intersection, trackstanding at a red light when my front tire blew and the bike dropped to the rim. I promptly jumped off and walked the bike out of the road to check it out. The tire was off the rim, and the tube blown. Now I understand that this can happen if a tire is poorly/unevenly mounted, but I honestly don't know how that could have been for me. I always install my tubes with just enough air to hold the tube's profile so they kind of 'drop' into position and away from the bead when I'm installing them. Secondly, I always partly inflate and roll the tire back on each side all the way around to check for the tube trying to get pinched before fully inflating. In doing this I imagine that I may have taken the tire out of 'center' from the wheel, but I would be pretty surprised.

My questions for the day are as follows:

How sensitive are tires while being mounted with regards to 'centering' the bead all the way around before inflating?

Could the tire have a faulty bead, and need to be exchanged before continuing to use it?

I've ridden bikes for years, and had been taught at an early age to be very careful and to take every precaution while changing tires/tubes and inflating, and I'm just not sure how much more careful I can be. I really don't like the thought of spontaneous ejection of my tire from the rim while riding near traffic. Thanks for your time.

-J