Mountain bikers destroy the natural environment and give ramblers cancer. The tread patterns left behind, when viewed at a typical walking speed of 3mph, reinforce negative alpha waves and cause schizophrenia, paranoia and homosexuality. The sight of these monsters' spandex-clad buttocks retreating into the distance makes me come over all funny. I just need to go to the toilet.
Oh, hang on, this isn't rec.bicycles.