[Retric]

So if you wear a helmet, there is a half of a thousandth of a percent chance that you will benefit from it.

That's per year, your lifetime risk is ~50x that. Or, .0005% * 50 = 1 in 4,000 which is a fairly large reduction in risk of death. Granted being a heavy smoker is ~1 in 3 chance of early death and plenty of people still smoke but this is one of those things that can kill you when your young.

PS: I would also assume that as the numbers of hours / year increases so do your risks. I don't think the 80 million people average more than ~2-5 hours per week riding so more riding time = more risk.

[mdemare]

1 in 4000 over a lifetime is not a fairly large reduction of risk - it's a very small reduction of risk. There's a much bigger payoff in thinking about the 3999/4000 chance that something else will kill you.

[Retric]

I feel those are bad odds. Plenty of other people are happy with them.

Also, that's 1 in 4000 before 60 (60 - 10 = 50). You have a 12% risk of death before 60 which means if you died before 60 the there is a 1 in 500 shot that it was biking without a helmet that killed you. Granted a significantly increased change that it was biking, but using a helmet would not have saved you.

I would agree that biking after 60 without a helmet does not really increase your death chances that much.