[ScottBurson]

Anecdatum: I recently learned that an old friend of mine had died in a bike accident. No other vehicle was involved; he hit a road hazard (I'm not sure exactly what, but perhaps an uncovered storm drain) and landed on his head. He was wearing a helmet, but it didn't save him.

I've always worn a helmet when cycling -- and I'll continue to do so -- but I've never had an accident in which it mattered, and I don't think it changes the odds as much as you suggest.

[notatoad]

As i said, a helmet doesn't remove all risk. I don't mean to imply that as long as you're wearing a helmet you're invincible.

There seems to be a strong opinion in these comments that because a bike helmet isn't a magical force field that prevents any possible injury, you shouldn't wear one (with the implication that because helmets don't protect you from every possible injury, you shouldn't ride a bike). All i'm trying to say is that helmets are better than no helmets, and no matter what safety precautions you take, risk is inherent in everything we do.

[reinout]

Helmets better than no helmets is not necessarily true, strangely. Perhaps on an individual right-now level, but not long term. The reason: the biggest protection you can have as a cyclist is lots of cyclists on the road. Helmets lower bike use, so in the end you'll be a lone, vulnerable road warrior...

Btw, would you also wear your cycling helmet while walking on the pavement as a pedestrian? At least in the Netherlands there are more head injuries for pedestrians that fall or hit something than cycling-related head injuries. :-)