...Of my Trek 820. I went for a ride on easter on 5 miles of 3-4 inch deep mud and 9-12 inch high roots on climbs and decents...and the 820 powered through all of it. Avg. speed was 10 mph, and I think my bike ended up with 10 pounds of mud on it after the ride. I have never been more inpressed with it's performance. Budget riders, do not be fooled by reviews of this bike, as it can handle a lot of abuse, and is very trail savvy!!