I did a search here a little while ago on tire wear and someone mentioned they only got 600 or 700 miles out of their stock Kendas (only sticks out in my mind cuz I was looking into my mercier at the time and it comes with the same tires). Just order another rear, tires are cheap. If color isnt an issue, these look like a good deal (I replaced my kendas with them)
http://www.performancebike.com/shop/...tegory_ID=5420
Might wanna rotate the front to the back so you can use that one up too.