Fun facts about helmets

I used to be a product manager of a bike company. Now I’m the Product Developer of a helmet company.

We don’t make anything most T.R. members would want (read: it’s for the commuter who values style over aero, ventilation and weight) but occasionally I get to work with some folks who have designed some really rad stuff.

My current project is a kid’s helmet. I got to work with a woman who designed the Bell Z20 and an engineer who worked on all the previous Smith helmets.

Some background on how helmets are made and why they’re expensive.

  1. Much like the auto industry, Bell makes their first iterations of helmets out of clay. They’re then 3D scanned and brought into CAD (that’s how my company does it too).
  2. The reason helmets are so expensive is because when the mold is made every undercut has to be a different core — that is, a part of the mold that can be removed in such a way that it doesn’t catch on any other part of the helmet.
  3. Cores are CNCed. Every additional core adds $1500-2000 USD to the cost of the mold. 1 mold starts around $25,000. If you look at all the undercuts on the Z20 you can start to think about how expensive 1 mold for 1 size of helmet is.
  4. Depending on the forecast there might be 4-8 molds. Chew on that figure for a little bit.
  5. That cost isn’t as big of a deal as the fact that each core adds labor time and slows down the production process. Let’s say $1.00 at MFG = $4 at retail.
  6. Around 40 helmets are made per size and are in-house tested to the appropriate standard. That’s 120 helmets per size if you’re doing CPSC, CE, AU.
  7. Then you have to send the helmets out to a 3rd party to get them certified. $8000 - $10k per size.

Ok. So now you know something about helmet MFG.

Here’s a fun tidbit of information I learned on Friday:

When I was talking to the Smith guy we got onto the topic of aero helmets. The Smith helmets were put up against other brands in terms of aero. (CFD and real wind tunnel). The Smith Network is apparently just as fast as the Specialized Evade. But it was designed as a commuter helmet and because of that was never marketed as anything else.

I recognize that I haven’t seen the testing protocol and 100% understand that they could be testing the helmet in a very specific way (e.g. 25 minutes at 0 yaw on a dummy as opposed to hours and hours on Tom Boonen’s head, in a wind tunnel, etc). But it’s a great reminder that some things that aren’t designed to be fast might actually be fast and some things that are designed to be fast are actually slow (Looking at you Troxel Ti helmet from 1992.)

OK. Off to ride some crits.


Great info! Molded in the US or overseas? How do they make the outer cover that contains the molded foam? Vacuum forming?

There are 3 types of helmet construction:

  1. Hard Shell - This is your Nutcase, Bern, ProTec, Thousand (my company). You have 2 parts EPS (expanded polystyrene i.e. the foam part), and ABS (acrylonitrile butadiene styrene i.e. the shell). The EPS has its own mold (something like 70% of EPS is sourced from a company in Ohio and shipped to China… how weird huh?). The ABS also has its own mold. Both are made, the ABS is warmed up a little bit, glue is applied to the EPS (think hot glue gun) and they’re stuck together. It’s a pretty simple process and relatively inexpensive (compared to road/aero helmets).

  2. Tape On. These are your Target/Walmart helmets. They’re also the helmets that you see people wearing w/out the plastic shell on top. It’s a similar process but the shell is PC (polycarbonate). The holes for vents in the shell are cut out with a 5-axis CNC router. The EPS gets some double stick tape, the shell is applied and tape is applied around the perimeter to keep everything together. The helmets are usually simple shapes (think kids helmets with Spiderman or Elsa on them) so the molds are simple (Cheap) and the labor is really fast. That’s how they get to be $30 USD>

  3. In Mold: The PC shell is made (yeah vacu-form) and then placed into a second mold where the EPS is injected. This means that the edges of the PC look cleaner. It also means that you can do more complex shapes. The labor involved is 2-3x more than a tape on. It’s a lighter helmet. Usually more ventilated.

Some companies layer different densities of foam to make the helmets “safer.” A harder foam on top helps pass the certification tests and a softer foam inside helps keep the skull happy. Bell does this. It’s not that different than what Smith does with koyroid.

I do not know of a MFG that makes helmets in the US. At least for bikes. This MFG process is energy and labor heavy. Start with engineering and CAD. Then CNC work, raw materials, labor rates. Then fun things like environmental concerns. Even the Trumpian EPA does a better job than some countries in Asia (China is honestly getting a lot better. . . . One day I’ll tell you kids about the great Chinese cardboard shortage of 2016 (seriously, that was a real thing and made my life very difficult for the Q1 that year)).

Fun info #2: Fruitcake, you know, the xmas thing that no one likes, does a better job than EPS at protecting the noggin. If helmet companies recycled fruitcake and put it in their helmets, every helmet would score 5-stars with the Virginia Tech helmet testing protocol.

The moral(s) of the story: No one likes fruitcake and engineers will find great way to get rid of shit they don’t like.

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:eyes: I like it. Send your fruitcake my way and I’ll protect my head and line my stomach


Great information. Thanks. Any insight on the efficacy of the Bontraeger wave cell product? Thanks.

P.s. If anyone wants info on the Air Traffic Control system, my job, just ask!:wink::wink:

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Which is the more accurate depiction of your job: Top Gun or Airplane? :joy:

So without getting too technical, what do you make of the Trek/Bontrager Wavecell design? I’m not sold on it yet, mostly because I can’t scratch my head, but with MIPS I can LOL

This would be like the SNL popcorn airbag. When you get in a wreck, you’d have a snack while you wait for help.

In your opinion what is the safest brand of high end cycling helmets on the market?

I think it’s like taking more vitamins than the daily recommendation. You could be preventing a cold or helping recovery or you could be making expensive pee.

We don’t exactly know how much safer these technologies are. But having seen the effects of a TBI I know I’d do my best to prevent one. Everyone can skew their data to make it look better than someone else’s (yaw angles in a wind tunnel or picking the best data when the wind is swept is common practice in aero marketing) but I’m pretty impressed with what I’ve seen for WaveCell. Is it better than MIPS? I dunno. Standardized testing protocols for this stuff along with publishing the data in a national repository would be amazing but that’s not going to happen.

One MFG once published their data and said that their helmet was safer. Unfortunately someone still got injured and sued that company. Now MFGs are scared to publish data because that opens them up to legal issues.

Finally, unless you have an engineering degree (I don’t) it’d be pretty difficult to look at the testing data and say that one helmet is definitely safer than another. e.g. one brand might test 2x better for frontal impact and another might test 3x better for side impact and yet a 3rd might test 4x better for rear impact but 1/3 as good with front impact and 1/2 as good with side impact. Which one is better?

At that point you really need to decide what kind of crash you’re gonna have and choose the helmet that fits that crash.

This goes to what I was saying above. I wish I could tell you.

If you plan on getting hit by a car and dragged 50 feet I’d suggest a hardshell helmet. If you plan on falling off the bike and hitting a rock with your occipital lobe, then go for something with more rear coverage. If you plan on crashing on some rebar maybe go with something that has less vents.

If you want the safest . . . maybe choose the helmet with thickest foam everywhere. You’ll look like a mushroom and won’t be aero but you’ll be a bit safer.

I honestly wish I could give definitive answers but even if we tested every point on a helmet in a lab there’s no telling if your crash (everyone’s number will be picked one day) will be anything like the tests.


An Ali express protone helmet, is it that much different from the original considering it’s a mould from polystyrene. The cost is so vastly different, if you’re a bit strapped on cash is it good enough on your opinion?

Cancer drugs are expensive. Would you buy those off of Ali Express?
Birth control is expensive. Would you buy that off of Ali Express?
Children are expensive. Would you buy one off of Ali Express?

There are legitimate reasons why things are expensive.
If you’re seeing it cheaper it is either:

  1. Stolen

  2. Counterfeit.

  3. The factory that makes is selling stuff out the back door.

  4. Buying stolen things is bad karma.

  5. I’m betting the helmet won’t protect you. Maybe the foam is fine but what about the straps and buckles? Are those going to hold when you slam your head into the ground at 30mph?

  6. If a factory is doing that, how do you know that the factory isn’t cutting corners with MFG? Do you really want to risk your life with that?

You have 2 good options:

  1. Find last years model on close out.
  2. Find a less expensive helmet and buy that.

I wish it was different but it isn’t.

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Thanks for all the info. I like the “What kind of crash do you plan to have”

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