Alex_is_emo

Okay, long story short.

I prefer wearing other helmets other than bike helmets.

Here is why.

I use my military helmet because I feel a lot safer with it on. Foam pads, surrounded by bullet resistant kevlar. I'm sure people are going to think I'm crazy but it's similar feel inside to motorcycle helmets. Which are ussually basically just a big foam pad that encompass all of your head.

Why are bike helmets made out of hard foam? I don't really see how that's going to protect your head better than a motorcycle helmet, or military helmet with foam pads inside. Oh yeah. Dirtbike helmets have similar system with foam pads inside. The motorcyle and dirt bike helmets are designed for higher speeds, and the military helmet pad system feels similar to those helmets so aside from the added weight and heat I don't see how using that over a regular bike helmet is bad? I don't mind the heat, I ussually ride at night because it's safer and I'm used to the weight, I barely notice, and it's great for winter.

I'm asking on here because another cyclist I've encountered stopped me and said my helmet isn't going to save me in a crash. He went on to say I might as well be wearing nothing. I'm like I don't think so. I've had a couple crashes in this and during both I could barely tell I hit my head, only way I found out was because the paint was scuffed up. As a kid when I had a regular bike helmet I remember that thing, the hard foam inside cracked and I remember my head hurting some. He said something about my brain knocking around in my skull and I might have got concussions and didn't know or something. Idk how that's true, I mean same could be said about a regular bike helmet, or a motorcycle helmet. He also said if I got hit by a car the added weight could snap my neck even if the helmet protected my head. Idk, maybe, but this helmet isn't much heavier than some of those full faced motorcycle and dirtbike helmets. I don't really see how an extra pound would snap my neck. And I'm sure by not my neck muscle must be stronger than average since everyone who tries on my military helmet says it feels heavy but I barely notice.
He said I should do some research about it. So that's what I'm doing.

LesterOfPuppets

The worst part about using that as a bicycle helmet is the lack of a hard shell, IMO. The kevlar wrap could have a tendency to grip the road a bit in many crash scenarios and could very well lead to neck injuries.

Alex_is_emo

Wait, what has a lack of a hard shell? The kevlar helmet definitely has a really hard shell, thick too. Not sure about gripping compared to I guess regular plastic shell. Maybe a little more, it's not as smooth, shiny, and slippery but it doesn't seem to grip anything much.

LesterOfPuppets

I'm not familiar with all helmets used by military these days but I was thinking of this type while posting. They just look a little grippy for my taste.

Alex_is_emo

Yeah, that's if you have the helmet cover on. You can take it off. Mine is basically the PASGT with the upgraded an LWH/ACH foam lining system.
The shell looks like this basically.

achoo

The EPS of a bicycle helmet is designed to absorb energy in a blunt-force impact. It's also vented.

A military helmet is designed to stop shrapnel and bullets. It's not vented.

If you don't care about venting and expect to get shot at and/or shelled, a military helmet is better. I doubt a military-type helmet is going to absorb as much energy as a bicycle helmet when your noggin hits the pavement.

"But it's just FOAM!"

And you're a materials engineer?

Alex_is_emo

Yeah, that's sort of what the cyclist was telling me.
But the thing is the foam pads are a lot softer than the bike foam, which is pretty hard. If the soft foam is actually a problem. Then why do motorcycle and dirtbike helmets have soft foam padding?

FBinNY 

There are two basic type of helmets.

One is intended to protect a stationary head from moving objects. For these the primary goal is to prevent penetration by defecting said projectiles.

The other is intended to protect a moving head form impact with a stationary object. Here the object is to provide a "crumple zone" to increase the length of time from initial contact to full stop, thereby reducing the G-force of the impact. These act like the crumple zones in cars, or the drums of water protecting bridge pillars along highways.

Bike helmets are of the second type and their design and construction reflects that.

CommuteCommando

I am a mechanical engineer with a trade background. What you say is valid, but the helmet could be adapted by cutting vents with an abrasive wheel on a Dremel, and could be painted to make it lower friction. After all is said and done, buying a bike specific helmet would be cheaper and protect better, but if he wants a project, I say why not. It will be better than bare headed.

achoo

Which tells me the foam pads in the military helmet aren't going to absorb much if any energy when your head hits the pavement, while the EPS in the bike helmet will.

There's not much distance for the padding in a military-style helmet to absorb that energy, and energy is force X distance. A soft, thin pad isn't going to absorb anything significant. I'm not sure how the shell of such a helmet would do, but I suspect it would just transmit the of the blunt impact, although it would probably do a really good job of protecting your skull from road rash, likely much better in that regard than an EPS bike helmet. (Which is why motorcycle helmets are much harder than bicycle helmets - you won't skid far enough in most bicycle falls to grind half your skull off against the pavement...)

Alex_is_emo

The pads aren't really thin per se.

Here is the inside.

unterhausen

I was in the military when the first kevlar helmet came into widespread use. It's heavy. Haven't seen one of the more recent ones, I can't imagine they have gotten a whole light lighter given the need to stop bullets

LesterOfPuppets

They typically have a thicker shell and the foam makes a lot of contact with your head which makes you very hot.

Bicycle helmets are much lighter and cooler. Bicycle helmets would not work very well for MC riding because bike helmets are only really good for a single hard impact but at MC speeds you have a good chance of experiencing multiple hard impacts in one crash.

Coal Buster

I was involved in helmet testing and development back in the early eighties when the push from the cpsc really came on strong. Thousands of engineering hours of development and hundreds of thousands of dollars worth of testing and equipment was used even back then to come up with the early helmet designs. Someone has already thought about the things you've mentioned. Specialized testing evolved for each helmet in its specific use. Would a combat helmet meet the requirements for bicycle use? Who knows? It certainly wasn't tested for that.

As far as your anti-helmet friend, one thing I found when I was in that field was that the guys who didn't want to wear helmets, or seat belts, or armored shoes, or other safety gear would grasp onto the 1-in-one million occurrence where using the safety device would actually cause more harm than good, rumored or factual, and use that as an excuse as to why all such devices are dangerous.

degnaw

Motorcycle helmets have soft foam in addition to (not instead of) bike helmet type "hard" foam.

Joe Minton

I have tested the current military helmet (in a certified laboratory which I managed). We did not test the samples as they were delivered because they would have destroyed our rather expensive equipment. We instead tested those same helmets with attenuating liners. Some of the results were impressive.

The current military helmet is designed to stop an A*47 round from 100 meters; it is not designed to attenuate impact against solid objects (like the ground). If you’re going to hit the ground with your head, the current military helmet is of no use at all. No use at all.

There are several sites dedicated to providing impact-attenuating liners to our troops in the field. The majority of severe and lasting injuries in Iraqi and Afghanistan are/were brain injuries (IEDs). A motorcycle helmet would have prevented a majority of those injuries (my considered opinion).

With the single exception or being shot (in the helmet) by a distant Ak*7 wielder, the current military standard helmet is of little use other than carrying ‘stuff’.

Joe

Looigi

Yeah. The soft foam in motorcycle helmets is usually referred to as comfort padding. The foam that is operative in absorbing impact energy is the relative thick hard non-resilient Styrofoam layer. The recommendation for racing helmets is to choose one that fits as tight as possible which compresses the comfort foam and reduces the distance the head will travel before contacting the hard foam during and impact.

The hard shell on motorcycle helmets is designed to mitigate impacting edges or sharp objects. Though a good idea, it's dispensed with in bicycle helmets to lighten weight. Bicycle helmets have a thin polyester outer layer which is primarily cosmetic and can serve to help hold the hard foam together during an impact. This, or other structural elements can allow larger and/or more ventilation holes. On some very inexpensive helmets the polyester layer is not structurally attached or bound to the foam layer so serves only cosmetic purposes.

rydabent

I have mentioned before, rather than the thin plastic over the foam of todays helmets, I wish I could buy a new Tourlite helmet like the one I had back in the late 80s. It had lexan shell which of course was tough as nails, with foam of course inside. It was very protective, and not all that heavy.

Alex_is_emo

I still think a helmet is better than no helmet. But I'll take a look at some bike helms. I'll try something like this so maybe I can make sure I can still use my cat eye band to hold up my helmet light.

gdhillard

I ride with a Nutcase helmet. It feels more comfortable, and much more substantial than a traditional bike helmet, and covers the back of my head.

Chitown_Mike

How do you like the helmet? I am looking for something with less venting for the winter, and like the OP I had looked at surplus military helmets but felt they wouldn't adequately protected my noggin from a road knockin.

lostarchitect 

Consumer Reports gave these helmets fairly bad ratings a while back. I don't know if they have changed anything to update them, but the general consensus is that skateboard style helmets are not the best on a bike.

Nutcase, Bern helmets receive "poor" impact rating from Consumer Reports - BikePortland.org

gdhillard

I haven't tested it, thank goodness, and knock on wood. But the foam is substantial, and the shell is a lot more sturdy than the thin plastic found on my Giro. The shape seems better, also, in that it covers the back of my head, and seems unlikely to slip to the side on impact. I don't rely on CR much, having had a few areas where I actually had some expertise in the items they reviewed, and found them way off the mark.

gdhillard

Followed the link. Found the following:
To test the helmets, Consumer Reports used, “an apparatus that drops them at about 11 or 14 mph onto differently shaped anvils.” A tester told ABC TV that, “The impact test simulates what happens when a helmet impacts different surfaces, like a flat surface like a street, a rounded triangle like a curb, and a hemispherical surface, which simulates hitting a rock.”
Sounds like CR, in that impact is tested with a machine that provides a straight drop, with no shift, slide or tumble forces involved. The ability of a helmet to stay in place and intact is not tested at all in this process, although I would think that bailing off the bike, and tumbling onto the ground at speed would have a variety of impacts and stresses that would find the Nutcase offering more protection that the standard, sit on top slab of foam that my Giro is. I appreciate the information, but would prefer some real world testing. Anybody crash in one of these?

jyl

I suspect that the variety of head shapes would make the kind of testing you are suggesting very difficult.

Conventional "roadie" type helmets are wide enough to protect your head when falling on a flat road, if (big if) you've strapped them securely. If you land on a curb or other protrusion, then that is a different story.

Road bike helmets are designed to be light and to ventilate well. That is a major requirement. If we didn't need light weight and lots of ventilation, clearly we could have more protective helmets with more coverage, thicker material, etc. Already we can choose BMX and downhill helmets that are full face and go down past the ears. Not many people are willing to ride with those, but they are available for those who want them.

I read that Nutcase "revised" their helmets after the CU report. I couldn't find any details as to what they did.