What level of helmet thwack should retire a helmet?

[Tom K.]

@RobSN keep in mind when shopping for a new helmet that a lot of mfgs give a pretty good credit on a new helmet if you return the old one.

Engineer geeks like me like to inspect them, test them, cut them into pieces, etc., all in the name of learning more.

 

[Henry]

A helmet has three critical safety parts. The shell protects against penetration and spreads the load. The liner, expanded polystyrene or koroyd or similar, absorbs shock. The strap (properly adjusted, please) hold the helmet in place on your head if you tumble. Damage to any of these is reason for a new helmet. Even if damage isn't visible, as noted above, one strong impact may damage parts enough that a new helmet is very prudent. The MIPS feature absorbs rotation to lessen the chance of a glancing blow rotating the skull around the brain floating in its fluid. (A concussion is, simply stated, when the inside of the skull slams the brain floating in its fluid. "...sudden movement can cause the brain to bounce around or twist in the skull, creating chemical changes in the brain and sometimes stretching and damaging brain cells." https://www.cdc.gov/headsup/basics/concussion_whatis.html )

So...buy a new helmet before the old one falls apart or otherwise doesn't protect your brain. Get one that fits right. Some skulls are round, some are oval, some are long oval. Find a good fit for the best protection. Don't wear the helmet over a puffy knit cap...the puffy part lets the head slam into the interior of the helmet, not the best protection.

 

[VickieH]

I wouldn't rely solely on the amount of thwack. If you were "suddenly on the ground" and don't know anything about the fall itself -- what you were doing just before, or how your body actually fell, etc -- you might want to get a new helmet.

 

[raytseng]

.The MIPS feature absorbs rotation to lessen the chance of a glancing blow rotating the skull around the brain floating in its fluid.

Don't wear the helmet over a puffy knit cap...the puffy part lets the head slam into the interior of the helmet, not the best protection.

I agree with you that your advice in general is good and correct. So stop reading now if not interested in pedantic details from someone on the internet

To jump into the weeds a little bit though, I think I read some articles that there was practical evidence and studies that showed in real life snowsports, the mips feature is not as vital vs the lab results. Specially the reasoning was in real humans the helmet is slightly looser than the lab test dummy. And real humans are wearing a balaclava, skull caps or beanies that end up basically working like an additional mips-like sliding layer.

Getting the mips version of a helmet has no downside except for small price premium, so I have no issue with that advice.

So my nitpick is more just about the absolute advice to don't wear a hat layer under the helmet. With a properly strapped in compressed knit beanie, at best there is some extra cushioning can add extra distance for the velocity to dissipate which is good. More distance to decelerate is everything. At worse, it is a tradeoff of impact protection for better rotational protection.

I think the jury is still out on this, my point is it is not an absolute safety decision on the hat under helmet.

Ski helmets are all about tradeoffs for comfort and skier performance in exchange for safety, so it's all a compromise already anyway.

 

[skibum4ever]

I wouldn't rely solely on the amount of thwack. If you were "suddenly on the ground" and don't know anything about the fall itself -- what you were doing just before, or how your body actually fell, etc -- you might want to get a new helmet.

That describes my fall pretty well.

 

[RobSN]

If you were "suddenly on the ground" and don't know anything about the fall itself -- what you were doing just before, or how your body actually fell, etc

@VickieH I'm pretty sure I was skiing just before , and I do recall that when everything went wrong and I was flying forward (without, as I discovered later, one of my skis) I was able to form the thought "Oh fu..." but didn't get any further before thunk.

Interestingly, while I wasn't too bad getting back from the hill, by the next morning both hips hurt such that my locomotion was like a 90-year-old which may possibly mean that the loss of one ski caused a yanking of the legs. My right shoulder also hurt a lot. I guess the adrenaline on the hill covered those aches and pains up.

Anyway, based on all the advice, a new helmet is the order of the day!

 

[Jeff N]

If I thumped hard enough to feel like my bell had been rung, probably good to replace the helmet.

My helmet saving my life story was the now replaced chair 1 at Loveland. I have a brother in law that… isn’t the most reliable at loading a lift- inattentive or fumbling with gear or slow to get to the line or…

Anyways, we were loading the chair and he had one of his shitshow experiences getting tangled up moving out to the load line, and when we got untangled I was finally turning back to catch the chair… and got hit with the upper crossbar of the carrier right where it bolts onto the bit that goes up to the grip. It hit HARD. Instant headache. My sister points out that my helmet is broken- the 3 bolts that secure the upper crossbar to the pole that goes up to the grip had indented 3 large holes in the helmet and shattered the styrofoam. I wouldn’t want those same 3 punctures in my skull.

 

[RobSN]

... and new helmet is due to arrive on Thursday .

 

[Castle Dave]

The elephant in the room of this thread is the fact any hard impact to your head will require a CT scan to rule out a brain bleed. If you ignore the possibility you may wake up dead. See my post #14

 

[VickieH]

Another excellent rule of thumb: If your fall necessitates a CT scan of your head, you need to get a new helmet ... regardless of the results of the scan.

 

[Rudi Riet]

And real humans are wearing a balaclava, skull caps or beanies that end up basically working like an additional mips-like sliding layer.

...

So my nitpick is more just about the absolute advice to don't wear a hat layer under the helmet. With a properly strapped in compressed knit beanie, at best there is some extra cushioning can add extra distance for the velocity to dissipate which is good. More distance to decelerate is everything. At worse, it is a tradeoff of impact protection for better rotational protection.

My $0.02: if you can fit anything more than an ultra lightweight skullcap or balaclava under a helmet the helmet is too big to properly serve its purpose. And most folks don't wear the straps tight enough, or cinch up any fit dial, etc. When this is the case the helmet is performative protection, at best.

A helmet should be close-fitting, and when it is the helmet will provide better insulation than any cap/hat. If you need extra insulation, pull a hood over the helmet - most modern ski jackets have hoods that are compatible with helmets, and the hood does little to affect the function of the helmet - far less than wearing a knit beanie under the helmet.

I won't get further into the weeds here, but know that a properly fitting helmet can help mitigate the severity of head injuries. Some impacts go beyond the design specification of snow sports helmets. Some snow sports helmets meet more exacting standards (e.g. a FIS certified helmet for alpine racing).

As far as replacement is concerned I use the same metric as with my bike helmets: a good knock, even without visible damage to the outer shell or the surface EPS foam, warrants replacing the lid. It's a small price to pay in the long run.

 

[RobSN]

As far as replacement is concerned I use the same metric as with my bike helmets: a good knock, even without visible damage to the outer shell or the surface EPS foam, warrants replacing the lid. It's a small price to pay in the long run.

Yep, done. My thwack was, frankly, not that hard, but it was clearly audible. So on a scale of 1-10, I'd imagine a 4. But the helmet was 4 years old and as everyone has said, it's cheap at the price. [My only time with a bike helmet was when I went down on black ice and hit HARD breaking my collar bone as well - I've used this example in the Pugcycle forum because it all happened so fast there was no way I could have held my head up - an example of why helmets are so important and, it goes without saying, that bike helmet was replaced]

 

[James]

A helmet should be close-fitting, and when it is the helmet will provide better insulation than any cap/hat.

Maybe a race one. Helmets have gotten colder over the years as they’ve concentrated on ventilation.

 

[Andy Mink]

This is/was my adult son's helmet after a smack down on a snowboard. Needless to say, it was replaced. No CT scan but he was monitored for several days. The foam was shattered too. Looking at it now the hard connectiin for the goggle strap seems like it would be a force multiplier, like the squatchee on a ball cap.

 

[Rudi Riet]

Maybe a race one. Helmets have gotten colder over the years as they’ve concentrated on ventilation.

I wear a freeride helmet 90 percent of the time I ski and coach so I'm familiar with the trend toward ventilation. These lids are still warmer than a beanie, perhaps only a thick knit wool cap with a fleece liner would measure up.

Hood + helmet = money when it comes to head warmth, especially if the wind is bracing or the precipitation steady.

 

[Bozzenhagen]

The Smith Vantage/Quantum MIPS helmets with the 20 or so vents are warm. I can easily go below 0F with them.

If the vents didn't close? Ouch.

 

[rj2]

I fell down the face at Kirkwood a few years ago. No cracks on my helmet, slight concussion. A week later, I tore my right carotid artery. Recovered and got a new Smith Vantage this year. I've also broken three bicycle helmets.

 

[James]

A week later, I tore my right carotid artery.

Yikes. What were your symptoms?

 

[rj2]

Yikes. What were your symptoms?

Loss of vision, slurred speech, weak left arm. Prognosis was transient ischemic attack (TIA). It's possible the crash caused a minor tear that slowly enlarged until symptoms manifested. Given the tear location behind the bone, a decision was made to let it heal naturally. I'm back to skiing and racing mountain bikes. During my short break from work, I took a few computers home and confirmed that I remembered admin passwords and procedures.

Never occured to me that blurred vision for hours was an indicator before arm weakness and speech impairment made my situation apparent to others. I knew my vision was compromised, but may have been cognitively impaired and in denial to ask for help. Pride before the fall.

 

[scvaughn]

The rule I follow with mountain biking helmets is, replace after any significant impact, and or the occurrence of visible damage. If neither occurs within 3-5 years, replace it out of principle. IMO, the same theories apply to snowsports helmets. Foam, nylon, and plastic degrade relatively quickly at altitude.