One flat at 600 miles on the rear 26X4 Kenda Juggernaut. Put in a Mr Tuffy liner and then Slimed both tires. No flats since. After about 4,000 miles (a couple of days ago) replaced the worn Kendas with Origin 8 Supercells. Reused the Mr. Tuffy I took out of the rear Kenda in the rear Origin8...