Originally Posted by
wphamilton
How rare the event, and the consequence of the event are the two equally important factors. You can't decide on the basis of either, without the other.
The consequences are (basically) the same for racers and normal riders.
Originally Posted by
wphamilton
Since I've begun riding, I have a fall of some sort every 5,000 to 12,000 miles, trending to the lower frequency over time.
A common argument here is that helmets aren't necessary because falls are extremely rare and, when they occur, the outcome is usually minor (this is without any fall practice). Some people go as far as saying they never fall (implying that they never will fall) and being common enough to make helmet wearing pointless for normal riders.
A related argument (also common) is that severe injuries (due to high-speed collisions with motor vehicles) are beyond doing much about.