Go outside and have a good look at the surface of the road. Remember when you were a kid, how much it hurt if you were running and fell and skinned your knees? Now imagine running flat out and diving face first onto the road - feel the asphalt tearing your legs and arms

Now imagine the same thing, but this time you're travelling at 30mph

The difference between having large amounts of your skin literally ripped away and replaced with deeply embedded rocks and dirt (and quite possibly several weeks in hospital) and just getting up again and continuing on your way? Boots, helmet, gloves and leathers