ok guys now that i have a bike with a odomiter, how often should i change the oil? on my old bike it was every other weekend of riding (between 50-150 miles/ 4-14 hours) should i look at the odomiter or the riding time? i have a little over 200 miles and have changed it 3 times (one after first 25 miles, then 100, then 200) i know if i go to the desert or dunes i will get alot more miles per hour than if i do tight trails. duning weekends i get probably 100+ miles in fewer hours as it takes me to do 20 miles of trail. whats your guys' take on this?