yet another "a helmet saved my life, i know that for a fact because it was smashed" comment reminded me of something, but i don't have time to write properly about it, so here are the quick thoughts. a couple of years ago i was knocked over by a minicab whose driver thought there would be no problem with his car occupying the same physical space as me at the pinch points on calthorpe street. one of the thousands of anecdotes in which somebody not wearing a helmet falls off a bicycle and doesn't die — anecdotes so mundane nobody bothers sharing them. rather, it wasn't a helmet that saved my life, but my trousers. i know for a fact that they saved my life because afterwards they had a small tear on the side where i hit the road.but i think we can go much further than anecdotes, i wonder whether maybe one could prove that trousers are as effective as helmets to the same evidential level as the best evidence that we have for helmets. because one of the big problems with that evidence — which compared the ratio of head injuries to other injuries between helmeted and non-helmeted hospitalised cyclists — is that it ignores the fact that there are different types of cycling, with different styles and risks, and whether one wears a helmet often depends on what type of cycling you're doing. extreme sports and racing cyclists are more likely to be injured in all sorts of places, and also more likely to wearing a helmet, than folk popping to the shops. similarly, extreme sports and racing cyclists are more likely to be wearing special shorts or lycra outfits than are utility and leisure cyclists, who will more likely be dressed for their destination/casually. i imagine there's a good chance that you could find a statistically significant difference in the ratio of head injuries to other injuries between lycra-wearing and normal trouser-wearing hospitalised cyclists. and if my hypothesis does turn out to be vindicated in this way, well, that should be more than enough to outlaw the use of bicycles when wearing anything other than trousers, for the fundamental issue is whether or not when bicycle riders crash and hit their heads they are benefited by wearing trousers.