I just took my bike to Irv Seaver in Orange to get some new tires installed and when I got home I discovered that the rear Metzler Z8 tire is Made In China. I'm pretty pissed off and I want to call them on Tuesday to remove it. The front tire is still Made in Germany. I friggin' can't believe another company is moving their production overseas. This is the last time I will install these tires on my bike.

I can certainly understand your concerns. Your tires are quite literally the thin lines of traction that stand between you and potential disaster.

The one thing that might (and not obviously) be in play here is this:

Some manufacturers outsource completely to a contractor in another country and leave both manufacturing and quality control to that contractor--and the result (hi W********!) is marginal quality goods.

Others pursue a supervised 'build to spec' approach and closely monitor the material inputs and build process and apply end to end process controls on site (with the intent of maintaining quality levels while cutting labor costs).

I'm not saying that's the case here as I don't know. Just pointing out that it's possible that Metzler (as others have done) is building in China this way.

Of course the final call on tires and what someone's comfortable with must ultimately be decided by the person who rides the bike that the tires are mounted on