What causes uneven tire wear?

I've noticed my KZ750 really goes through rear tires. The most recent tire is a Conti Twin K112 4.00-18. It's not exactly a budget tire, but after 3,000 miles it's already pretty shot.

The wear on the tire is pretty uneven and I'm wondering if there's something else going on that might be causing my bike to eat rear tires.

The tire has a center groove running all the way around the circumference of the tire. In some sections there's a fair amount of tread left on that center groove, I can see the wear bars and still have a bit to go before I reach them. In other sections of the tire though, the groove is gone, the wear bars have vanished and the tire is slick.

Is this a normal way for a tire to wear? I would think it would wear the same all the way around. It's not like I ride on one part of the tire more than others.

Would this happen if the tire wasn't properly balanced? I haven't noticed anything in riding the bike that makes me think the wheel's out of balance. It vibrates just about as much as a parallel twin tends to do.

If that's the only tire that has worn unevenly, it could just be a bad tire or possibly the tire was out of balance. If the problem has happened on other rear tires it is possible that your wheel is out of round. You may want to use a dial gauge to check the rim for roundness. Ed

I think the last rear tire suffered similarly uneven wear.