Yea the weird thing is that the tire looks pretty even from the side when you spin it, even near the valve, it's just a good bit heavier on that side. Its an older zipp 808. Maybe the valve extender I used is just on the heavier side? Or it's possible I didn't stretch the tire evenly, or put more glue on the one side or something. But I've already done a handful of races on these and other than this they've been great. Without the counter weight I've only noticed the wobble on descents over 40 mph.