I'm nearing the 100 hour Vet Intermediate mark on my 2008, 450. When I recently checked the valves, the clearances were slightly (.001+-) tighter than 15 hours ago. I keep excellent maintenance on my bike, change my oil after every 3 hours, and I'm not banging it against the rev limiter. So my question is, why do the valve clearances get smaller the more you ride. Wouldn't logic make the valves deteriorate the more your ride, thus making the clearances get larger eventually? What concept am I missing, am I over-thinking this? Gray, any help?