I took my new Felt Z85 out for its maiden voyage today, and it rode like a dream until the tube in my back tire blew 4 miles down the road. It wasn't pierced, it just ruptured, so the only thing I can figure is it was either an el cheapo tube or overinflated from the bike shop. Anyhow, I have ordered replacement continental tubes and I purchased Mr. Tuffy Bicycle tire liners, which are supposed to protect from thorns, glass, punctures, etc. Has anyone tried these, if so what is your experience? Are these liners with gatorskin tires virtually bullet proof?