It's not surprizing that you keep changing the subject, each time you lose the argument. Sincce mountain bikers go faster, they have greater momentum & hence exert greater force on the trail -- hence more erosion. Then multiply by how much farther they travel, and it becomes obvious (to any HONEST person, which doesn't include mountain bikers) that mountain bikers do FAR more damage than hikers. Vandeman still 1000, mountain bikers ZERO. Go ahead, change the subject again. It only proves that you lost the argument, and can't face the music, COWARD.

One, I'm not changing the subject at all.

Two, you've made this same statement three times now, in this thread, and I've refuted it every time with the equations, and the maths. You just keep restating the same ... without justifying it. I think you lose.

If you were right, you would have to violate the conservation of energy ... and in this universe you can't do that.