I have a mountain bike and a 26 inch tire. The bead along the side of the tire is made of steel wire ( as I guess most of them are) I noticed yesterday that the bead has a crossing thread pattern on both sides of the tire. is this how they were made or does this occur from over use? I have had this tire for about two years ( it is on the front of the bike) and I never really looked that carefully at the bead until I noticed it yesterday. Should I be concerened about the tire?