Ask the Expert Bike Tech: Flat Spots on Tires

This week’s question to the mighty bicycle expert, Victor actually comes from me.  A few months ago my road bike tires sort of flattened out…you might even say they turned square.  I had no clue what caused it, but they’ve since been switched out and I’ve got nice round tires once again.  But I was still curious as to what caused the tires to get that way, so I came to Victor for advice.

Here is Victor’s response to what causes flat spots, or squared tires:

  • http://anello-grande.blogspot.com/ Anello Grande

    I don’t believe it’s anything more then normal wear. All my road bike tires square off on the rear. The softer the compound, the faster the wear. It wears that way more so on the rear because the majority of the forces on the tire are to propel the bike and rider forward. The front tire has les weight on it, as well as taking care of more turning duties. Over and under inflation are great excuses to put blame on the user and not on the manufacturer. But truth is, if they developed tires that didn’t square off, they would be terrible to corner on.

    In order for rotation to work properly, the average rider would have to rotate about twice a month or more. Once you have a hint of a square top, it’s dangerous to swap the front and rear tire.
    http://sheldonbrown.com/tire-rotation.html