The CycleChat Helmet Debate Thread

[Justinslow]

Thinking something like "which" magazine?

 

[srw]

I suppose a good question would be - just what level of impact can a helmet withstand without it "cracking" or failing? Not what test it has passed, but what it actually can handle, independent tests, I'm surprised we have no information on this from a third party. Surely it would be fairly easy to buy a range of helmets and test them to destruction? Why has no organisation done this?

Probably because no-one is willing to wear the helmet while it's having a hammer aimed at it.

 

[mjr]

Thinking something like "which" magazine?

Which has done it. You'll have to buy it if you want the full story but the headline was that a Met helmet failed, as reported in http://road.cc/content/news/62272-which-stirs-helmet-debate-product-test

At that time, Which was basically pro helmet IIRC.

 

[Wobblers]

I suppose a good question would be - just what level of impact can a helmet withstand without it "cracking" or failing? Not what test it has passed, but what it actually can handle, independent tests, I'm surprised we have no information on this from a third party. Surely it would be fairly easy to buy a range of helmets and test them to destruction? Why has no organisation done this?

Now that is a very good question. I suspect that it is, at least in part, because such testing is difficult, especially to get consistent results. I'd like to see a realistic protocol that simulates both the falling impact and the horizontal velocity component. That at least would produce both the desired shear and compression components.

What I do find surprising is that there seems to have been little, if any work done using the standard crash test dummy head. These are usually instrumented so that the accelerations experienced during testing are measured. That there seems to be an absence of any published data using such standard and accepted methods is, for me, a worrying omission.

 

[Wobblers]

We do have one study that might be interesting. It is not independent as it was conducted by a researcher for Bell helmets. It is also getting on a bit now, being 2O years old, and it is about children's helmets.
No compression at all
Anyone who wants to believe that cycle helmets are a good thing, really ought to be concerned about this sort of thing.

Hmm. It says "no compression" on the inside of the helmet. That does not mean that the helmet did not compress. It merely means that any deformation did not propagate through the full thickness. After a brief read of that document what strikes me is the seeming absence of any rigour in that researcher's observations. This, I think, is due to the fact that it is impossible to tell from examining the helmet as to what forces it actually experienced during impact, and what forces were transmitted to the wearer. This is all vital data needed to properly evaluate helmet effectiveness, and it's entirely missing.

 

[Justinslow]

Now that is a very good question. I suspect that it is, at least in part, because such testing is difficult, especially to get consistent results. I'd like to see a realistic protocol that simulates both the falling impact and the horizontal velocity component. That at least would produce both the desired shear and compression components.

What I do find surprising is that there seems to have been little, if any work done using the standard crash test dummy head. These are usually instrumented so that the accelerations experienced during testing are measured. That there seems to be an absence of any published data using such standard and accepted methods is, for me, a worrying omission.

Yes that's what i meant, crash test dummies with sensors everywhere - actually measuring stuff independently?


I've just read a group test helmet review in this months "cycling plus" which was quite frankly utterly useless. No safety data whatsoever, but not unusual I guess, a motorcycle helmet review would probably be the same.

Leading on from this, why are the tests that the helmets have to pass set at such a low standard? Whoever thought that was an acceptable standard?

 

[Mugshot]

Leading on from this, why are the tests that the helmets have to pass set at such a low standard? Whoever thought that was an acceptable standard?

Quite likely it is the bare minimum that the manufacturers can get away with, and as we know people don't generally question the standards anyway. Why would the manufacturers bother with improving standards when so many cyclists are happy in their ignorance and keep shelling out thanks to promises of lighter and more aero?

 

[Mugshot]

In order to improve anything, should that be needed, is for helmet wearers to boycott helmets and demand higher standards.

Absolutely, but when you have cyclists so determined that any helmet is a good helmet and manufacturers comfortable in that knowledge, that would be no mean feat. A recent which helmet thread, and I suspect there are many others like it, asked for recommendations on a first helmet with the first consideration that it shouldn't be too sweaty, no mention of which one may offer the best impact resistance at all. Anything was going to be better, or, as I was told by my LBS when I last bought a helmet many years ago, they're all the same just some are lighter than others.

 

[MontyVeda]

In order to improve anything, should that be needed, is for helmet wearers to boycott helmets and demand higher standards.

...at which point they'll look at the helmet that might actually 'work' and say "I'm not wearing that on a bicycle!"

 

[Mugshot]

...at which point they'll look at the helmet that might actually 'work' and say "I'm not wearing that on a bicycle!"

Can't think why not;

Summary: We asked two noted helmet experts what thickness of foam would be required to turn a current bike helmet into an anti-concussion helmet by keeping the CPSC two-meter flat anvil drop test below 100g. Here is the result.

 

[mjr]

...at which point they'll look at the helmet that might actually 'work' and say "I'm not wearing that on a bicycle!"

That's basically happening, isn't it? Some Snell standards are slightly tougher than the Euro Norm but people buy the EN ones. Sadly, the reaction to deciding Snell-approved ones are unacceptable seems to be to decide that anything is better than nothing and buy the EN one.

 

[MontyVeda]

That's basically happening, isn't it? Some Snell standards are slightly tougher than the Euro Norm but people buy the EN ones. Sadly, the reaction to deciding Snell-approved ones are unacceptable seems to be to decide that anything is better than nothing and buy the EN one.

Aye.

A couple of years ago on here a poster had a helmet like this...

...but was worried about looking like a 'human cannonball' and wanted a 'normal' cycling helmet instead. I've no idea how effective the 'cannonball' helmet is but I'd hazard a guess that it's a bit better than this sort of thing...

I tend to put my faith in this sort of thing...

...I've had it for years.

 

[jefmcg]

Some Snell standards are slightly tougher than the Euro Norm but people buy the EN ones

Because that's what is available. I decided to go for Snell, and I had go online to find out which are included. The helmet I chose, Specialized Echelon I think, is listed as Snell on the Snell site, but the box said "meets one or more of the following standards..." I literally couldn't find one in Evans that explicitly claimed Snell, even in the fine print.

For all I know, Specialized use different specs in different markets, and my helmet isn't actually up to Snell standards

 

[Racing roadkill]

Insurers work on risk. If you reduce the apparent risks, the insurers are more likely to be sympathetic to your plight, in case of a traffic collision, or similar. For that reason I reckon that wearing a "silly pointless useless crap plastic ineffective" helmet, might be worthwhile. I've also conducted some 'helmet tests' in my time. Despite having my head walloped into various solid objects, whilst wearing a lid, I've never suffered a head injury. The one time I did get my head whacked into a solid object, whilst riding a bike, it did end up with a head injury / unpaid time off work, and it hurt. So I deduce, that wearing a decent well designed lid, has at least some merit. It's nice to have a choice though.

 

[ufkacbln]

I tend to put my faith in this sort of thing...

...I've had it for years.

Alas poor Yorick @MontyVeda , I knew him; a fellow of infinite jest, of most excellent fancy