A helmet might not guarantee safety, but it is an effective protection against a brain injury. If you fall off your bike and break your collarbone or leg or something, it's not really a big deal. Bones heal with virtually no permanent damage, brain injuries don't.
It isn't about removing all risk - some danger is inherent in pretty much everything you do. The point is to manage the risk, and take acceptable precautions where they are convenient.
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.
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.
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. :-)
This really hits it. A helmet isn't some all protective force field. If a truck is going to run you over, a helmet isn't going to save you.
I think helmets are associated with bikes, because before we used bikes to commute, which involves simply riding about town, we used bikes to rip through the woods inches away from trees and sharp rocks, or jumped them off of mounds of dirt, or flung road bikes down mountain roads at 50per. (at least those three seem to sum up my first 23 years of existence) I live in DC, got old, but still NEVER commute with a helmet, and feel perfectly safe all the time. In fact, tons more safe than when I try to get a training ride in. (for which I wear a helmet)
Generally, I've seen three types of injuries with regard to cycling -- the classic being the collar bone breaking, next up some road rash (ie, you know how to lay your bike down or slide out due to a rear flat tire at speed), and head trauma. The first two, the helmet is useless to help. The third? Usually pretty darn helpful.
Around here in Santa Cruz, a town known for biking -- many local builders, a couple of clubs, and a very forceful pro-bike lobby -- we still don't have the infrastructure that places like Portland or Amsterdam have. In fact, the roads are pretty much crap in most places. So you have to be careful. One recent solo accident involved a young adult who was biking at night on a dark road (dumb) but also not wearing a helmet. He crashed. Currently he is in critical condition. Pretty sure a helmet (and a light) would have helped him out.
Not really -- a helmet protects you from head injury. Is a car seatbelt useless because it doesn't do much for a side collision?
I don't ride much, but one time I was out is the rain and had to swerve on a intersection that happened to be made of cobblestone, and ended up going down hard on the slick stone. Had I not been wearing a helmet, I would have had a severe head trauma.
That type of accident is pretty common, and wearing the helmet avoids lots of needless suffering.
Must be a luck-signularity around where I live. I know several people saved by bike helmets, from small crashes of 2 bikes or bike vs immovable object. One happened last Saturday on an asphalt bike trail with no obstruction - the young man just went down and landed on his head. Busted his helmet all to hell. Got up and got back on his bike.
Lots of statistics thrown around here, and my anecdotes are not statistics, but they are a heck of a lot closer to actionable information that hot air. As for me, I don't regard a helmet as making bicycling seem dangerous, any more than wearing a raincoat makes walking outside seem dangerous. Its just part of my equipment, like the water bottle.
