Never before in a continuous riding career which commenced in 1966, have I ever worn out a front tyre before a rear tyre. I replaced the original tyres on my Versys at 9000klms. The rear was buggered, the front probably had 1000klms left on it. Now, 8500klms later the front tyre is slick and the rear is good for another 500klms. Previously, in Australia, I used to get 10-12,000 from a rear tyre and between 14-17000 from a front hoop. Certainly I am riding on winding mountain roads rather than the flats of the Northern Territory, but that shouldn't make so much difference. I have been told it may be due to the abrasiveness of concrete over bitumen roads. But, even so, why would a front tyre wear more than a rear?