:shrug:

It is what it is. I'm not Snell. In fact, they aren't even the relevant standard for most helmets anymore; that honor goes to the CPSC.

All of the advances in safety have to do with the second hit. With earlier helmet designs, the helmets were one-and-done. The first time your head bounced, it had protection. The second time, probably not. New helmets stay in one piece and they stay on your head. In fact, they are durable enough I routinely use them for a time after a minor hit, something I'd never do with the taped shell designs. It allows me to make a determination of helmet damage without worrying that some unseen little crack in the foam will cause the shell to collapse under a moderate hit.

The moral is: sometimes newer is better.

Secondary moral is: don't trust lawyers.

Corollary to secondary moral: standards are akin to lawyers.

I replaced my last one at 6 years, I'll probably replace my current one at 5-6 years. I've known too many people who have cracked their skulls to risk the unknown of an old helmet. Most car seats expire after 6 years it seems reasonable that a helmet would have a similar life span.

Once a year.

Once a day.

Sometimes I worry this might be compromising my safety.

Never have yet.

Get um at Goodwill.

Got this one last month for $1.99

Why?

I put about 6-7000 miles on them in a year and they get beat up, dents, sweat build up and the foam is flatter than a pancake so its not as comfortable.

What are you doing to your helmets that they get dents and flattened foam?

The foam gets flattened out with a lot of use and sometimes hang my helmet on the handle bars and it gets small dents that way.

Is it flattening out or do you get specks of black stuff (foam) on your forehead and in your hair before it appears to the eye as flattening out? Anyway you should be replacing your helmet long before what you have been doing, because once it begins to flatten your losing the foams ability to take the impact for your head.