What happens when a bicycle helmet meets the wheels of a car?

Apr 11, 2008 By Richard Masoner Posted in The Archives Tagged with Commute by Bike 6 Comments

Lest you’re ever tempted to believe claims that bike helmets can hold up to the weight of a truck, allow me to direct you to the Bicycle Helmet Safety Institute (aka Randy Swart) page demonstrating the true effectiveness of bicycle helmets when placed underneath a car. Click here for more photos, which feature sticky red fluids oozing across the pavement from underneath the car tire and what’s left of the bike helmets.Have a great weekend, all!

6 thoughts on “What happens when a bicycle helmet meets the wheels of a car?”

Tom says:

April 12, 2008 at 7:17 am

Thanks for the links.

What I love about “the helmet saved my life” stories is the survivor showing the helmet after the crash. In this case half the helmet was in two pieces. If his head was actually in that helmet wouldn’t the part of his head under the missing pieces be crushed.

What I don’t understand is why the helmet worshipers don’t look at that helmet and say: “What a piece of crap. I’m glad someone was looking out for me, because this helmet obviously was not up to the task.”

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Mike Myers says:

April 12, 2008 at 8:13 am

Why not do the same test with a motorcycle helmet? I doubt even a full face motorcycle helmet could withstand the test helmets.org did. Their methodology is flawed. When someone’s head is run over, its much like when you see the strongmen who let a car run over their abdominals. The vehicle is actually over the person for a very short period of time. The test that helmets.org did consisted of jacking a car up then slowly lowering the full weight of the car onto the helmet. Doesn’t seem like the same thing.

I don’t know if the original point of this posting was to start a helmet war, but I will relate my story. I was hit from behind while riding to work. The driver was in a huge GMC dually and his towing mirror slapped me in the back of the helmet at speed. I was knocked unconscious but awoke with no brain injury—-and a cracked helmet. It could have and would have been my skull if I was helmetless. No good could have come from that.

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Fritz says:

April 12, 2008 at 1:24 pm

No, sorry, the intent was not to start a helmet debate (that’s what my personal site is for). Randy Swart (the man behind the curtain of the BHSI and the guy who did the static test) is vociferously for mandatory helmet use.

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Samir says:

April 13, 2008 at 5:39 pm

Several years ago over at ogrish.com (shock site, do not go there) they had pictures of a motor cyclist who was run over by a truck. His head did go under the wheels and his brains were squirted through the front opening of the helmet. The helmet itself was squashed almost flat. So, I would say that although these tests were static, they give a good representation of what would happen to a head if it is driven over by a moving vehicle.

Also to note, those strongmen who allow vehicles to run over them are usually placed just after a ramp that will raise the moving vehicle to the height of the strongman. The speed of the vehicle allows the car to “almost” jump over the strongman. As such, very little weight is applied to the strongman. If they were not to use the launch ramp, the strongman’s abdomen would not supply enough resistance to force the car to rise, instead the tire would “plow through” the strongman. The bones would supply a bit of resistance, but depending on the type of vehicle, the strongman’s guts would either be shot out his mouth, or through his pants.

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nat says:

April 15, 2008 at 4:31 am

“The driver was in a huge GMC dually and his towing mirror slapped me in the back of the helmet at speed. I was knocked unconscious but awoke with no brain injury–and a cracked helmet. It could have and would have been my skull if I was helmetless. No good could have come from that.”

Yeah, my cousin used to do lots of cross-country long rides. And his comment was that the only thing he was ever worried about was the mirrors on motorhomes and people towing trailers–because they have no idea where the right side of their vehicle is [unlike professional drivers], and even if they get that part right, they forget about their mirror sticking out.

But as for your skull: maybe, maybe not. Given that the helmets are only rated for a ~14mph impact, the fact that your helmet was cracked *might* mean that you had exceeded that, and it had therefore done nothing to protect you. Or it might mean that it absorbed enough energy in the process of getting mushed to make the difference.

If we’re going to share anecdotal evidence: I bounced my [unhelmeted] head off a concrete wall at 20+mph, and didn’t suffer any head injury–and was a hell of a lot more lucid than the folks who came to my aid. (My brain may have been fine, but i had my share of other injuries.) Given that that exceeds the rated effectiveness of a bike helmet, and they’re designed to do their job by breaking, odds are that if i’d been wearing one it would’ve been trashed–but that doesn’t mean that i would’ve been seriously injured by not wearing one (which i wasn’t).

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justfrank says:

April 16, 2008 at 7:30 am

I don’t have an interesting personal anecdote or gruesome recollections of scenes witnessed to share, however, I would like to point out that the vast majority of cycling accidents do not result in the rider’s head under a wheel of a truck. In fact, the presence of a car is not necessary for a cyclist to suffer a head injury. You can fall off your bike at a speed lower that the 14mph someone mentioned and crack your skull. I’m with Mike: wear a helmet.

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What happens when a bicycle helmet meets the wheels of a car?

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