Peaks on helmets

[steveo269]

I get the debate on helmets and have no wish to open that particular can of worms again,FWIW I have a helmet but don't always wear it ,But what I don't understand is the problem with peaks on helmets,I've got one,I think it looks quite jaunty and it keeps the sun out of my eyes (a bit),what's the issue !

 

[swansonj]

Potentially increased risk of snagging on something and causing damage to the brain through rapid angular acceleration. That sheers off nerves as the brain rotates relative to the skull and causes serious long-term brain damage. It's hard to get good evidence on how big a problem this is with cycle helmets, but it's also hard to dispute that a protrusion of any sort on the helmet must increase the risk, however low. In my intermediate phase, after I'd starting reading the literature on helmets but before I had the courage to stop wearing one, I removed the detachable peak, to reduce the risk of rotational injury. We chose to make our children wear helmets when younger (they have both stopped now), solely to prevent a few headaches from low-speed contact with the ground, and I likewise removed the peaks.

 

[steveo269]

Ahh right, I thought it was some sort of fashion/performance thing

 

[swansonj]

Motor-cycle helmets are specified to have as smooth exteriors as possible. And there's a school of thought that one of the reasons evolution has left us with hair on our heads is because hair provides lower friction than skin, again reducing the risk of angular accelerations when hitting things.

One of the ways that woodpeckers can survive the massive accelerations from bashing trees all day long without brain damage is that their necks are adapted so their head accelerates largely linearly forwards and backwards rather than rotating as ours would do.

 

[ufkacbln]

Combination of the above 2 posts
The "snag point" scenario is a factor to consider, and also the reason for the "Smoother, rounder, safer" campaign in the US to make helmets more like motorcycle helmets

As with other helmet factors, it is up to you

If you assess the peak and feel that it is attached in such a way that in an accident it would break off and hence not cause a rotational injury then wear it, if you feel it is too robust and firmly fixed then don't


I chose a Giro Aspect as it was a smooth design without snag points, and it has a velcro attached material as opposed to plastic peak, which I think is probably safe enough, and a compromise on the old trick of a cloth cap under the helmet

 

[Citius]

,But what I don't understand is the problem with peaks on helmets,I've got one,I think it looks quite jaunty and it keeps the sun out of my eyes (a bit),what's the issue !

The issue is, they look stupid.

 

[shouldbeinbed]

As an infrequent helmet wearer, I've never considered the snag factor but TBH I think all of the peaks I've left on have been so flimsy as to tear off anyway (never experienced a snag tho so ???) & my own risk v benefit thoughts are that I feel I get more benefit from the sunshade effect than potential rotational injury worry.

Thinking about injury potential from a peak though, I reckon I'm more concerned if I went over the bars and faceplanted that the brittle plastic could shatter and produce sharp shards which may cut my face or injure an eye.

I primarily see & use a helmet as a high level mounting block for another set of lights though, so am more likely to snag or suffer a Schumacher like injury from those than the snap off peak. Again my personal risk v benefit swingometer prefers lights up there to not.

 

[Yellow Saddle]

I think peaks are lethal, with a rider. Stiff, plastic peaks, that is.

I get the issue with angular acceleration which is something I've only recently been alerted to thanks to some sensible mentions in this unmentionable topic. However, I think the manufacturers are trying to reduce the potential for snagging by making the peaks dismantle from the helmet upon contact. I say "think" but I'm not sure if there is a conscious effort to do so, I base my thoughts on one or two helmets I've looked at and owned.

I've attached to photos of one such peak that I've removed from a helmet because it scares the hell out of me. It is made from stiff plastic and hooks into the helmet using the peak's springy flexibility to keep the flimsy (by design I think) hooks engaged. A hard knock makes it come off the helmet.

This particular peak has hard plastic spikes. Hard enough to penetrate skin, eyes and noses and I can imagine scenarios where it will in fact, do so. I had a customer some years ago that was badly disfigured by her helmet's peak that penetrated her eye socket and somehow paralyzed one side of her face. She was very badly cut up and from what I could gauge, it was mostly the helmet that did the damage. I never saw the helmet but I can imagine what damage a peak like this can do.

Other peaks attach with Velcro and is made from sheet plastic moulded into a shape that gives it some stiffness. I've had the displeasure of going over the bars and hitting the trail face-first with such a helmet and visor. The visor came off and did no damage. The helmet itself, from what I can gauge, did no good or harm and simply moved out of the way, sliding backwards over my head However, my sunglasses cut me deeply under the eyes. I' now very weary of sharp plastic objects on my face.

Having said that, when I still used to ride in sunny places in a previous life, I really enjoyed the benefit of the peak. It kept the sun out of my eyes in morning and evening rides. I would imagine that a cycling cap worn under a helmet would provide the same shading benefit with less of the disadvantages of a hard plastic peak.

 

[Drago]

The peaks on all my helmets are fairly flimsy affairs with even flimsier mountings. On more than one occasion I've accidentally detached or partially detached one by accident and I've little doubt that in the event I went off for a head first jolly the peaks would be on their way long before they could ever snag.

Aside from my Cannondale lid, where the peak has fallen off and got lost, I leave them on for their utility in protecting the eyes from the elements and oncoming headlights. If anyone has any form data describing an incident where a peak has caused rotational spinal or brain stem injury I'd be keen to have a read, but I suspect such data is as ephemeral as the data with proves lids save lives.

 

[Yellow Saddle]

One of the ways that woodpeckers can survive the massive accelerations from bashing trees all day long without brain damage is that their necks are adapted so their head accelerates largely linearly forwards and backwards rather than rotating as ours would do.

I don't understand this reason for them surviving hammering of the brain. Surely then can still rotate their heads but choose not to rotate when pecking? Saying that their heads moves linearly when pecking doesn't explain why their brains can survive rapid accelerations.

 

[Yellow Saddle]

I chose a Giro Aspect as it was a smooth design without snag points, and it has a velcro attached material as opposed to plastic peak, which I think is probably safe enough, and a compromise on the old trick of a cloth cap under the helmet

On face value, it looks like this design has received some thought. Fabric peak and smooth design. contrasted to some designs with snaggy space-age exhaust pipes at the back, it makes better sense.

 

[swansonj]

I don't understand this reason for them surviving hammering of the brain. Surely then can still rotate their heads but choose not to rotate when pecking? Saying that their heads moves linearly when pecking doesn't explain why their brains can survive rapid accelerations.

A linear acceleration/deceleration to the brain merely causes impact damage, and the brain has a reasonably high tolerance to such impacts. (Woodpeckers also have soft insides to their skulls to further reduce the damage.)

A rotational acceleration sheers off nerves and blood supplies, which causes more damage at a lower level.

If you're going to bang the head, do it linearly not rotationally, a lesson that evolution has built in to the woodpecker's anatomy. Yes they can still rotate their head, and yes, we can still use even our necks to get a certain amount of linear motion, but if we tried doing what woodpeckers do, we'd be rotating the head, causing large angular decelerations, and damaging ourselves.

 

[Lemond]

The peak on my helmet pops off easily, so I use it depending on the weather. Rain today so on it goes.

 

[Yellow Saddle]

A linear acceleration/deceleration to the brain merely causes impact damage, and the brain has a reasonably high tolerance to such impacts. (Woodpeckers also have soft insides to their skulls to further reduce the damage.)

I wasn't aware that we/them have a higher tolerance to impact than rotation, but I get it now that it is pointed out.

A rotational acceleration sheers off nerves and blood supplies, which causes more damage at a lower level.

Cringe and make mental note not to watch tennis again.

If you're going to bang the head, do it linearly not rotationally, a lesson that evolution has built in to the woodpecker's anatomy. Yes they can still rotate their head, and yes, we can still use even our necks to get a certain amount of linear motion, but if we tried doing what woodpeckers do, we'd be rotating the head, causing large angular decelerations, and damaging ourselves.

Are you saying that they (woodpeckers) have some sort of extra mechanism that resists rotation whilst pecking? I can envisage a scenario where a linear peck can cause the beak to deflect off a hard side in the hole and cause the head to swivel. Is this the scenario that they can resist? Also, any idea how thick the cushioning is compared to a similar sized bird brain without a pecking inclination? Chickens also peck quite hard, albeit not as rapidly as woodpeckers.

 

[Crackle]

I took the peak off mine and was quite surprised how much shade it gave me in low sun, so it went back on. I'm liking the look of that helmet Cunobelin posted, mine's due for replacement and is old hat in terms of plastic peak and non smooth design. Time to move on.