Helmet Safety vs Aerodynamics
Here's what Grayham Rayne has to say about todays helmet options, which i found very informative;
"the charly visor fits pretty good, but needs some tape. You definitely loose some useability since you can't flip your visor up, but if you can forego looking ultra-sleek then this is the helmet.
Once you take off the visor of the stock helmet, the form factor for the bell drop is like inflating the surface area of a charly by .5" to 1" all around. It IS bigger, but it is also much, much safer. The helmet was made specifically for downhill mountain bike racing and spoke volumes to me.
When Justin Metcalf was injured, the road wasn't what did the damage, it was the trees and rocks off the side of the road. While Charly's are a great shell, and in most racing situations I believe they are safe for road impacts. It is the non-road impacts I worry about and was confronted with after Justin's accident.
So, the shopping began and the Bell Drop was what I found to be best.
To outfit it for longboarding was easy. A charly visor fits with electrical tape and the aero fairing is dead simple, but takes some revision to make it fit just right. The important thing to mention here is that the emphasis of building this helmet was to make something FAST, but very safe. The Bell drop was a starting point. Adding a visor and sealing up vents with electrical tape was step #2. The final step was really to point our that aerodynamics do not have to come at the expense of safety.
The aero helmets on the market right now have some fatal flaws that we should all be aware of:
-Paragliding helmets are made for light impacts. This is ok for road impacts, but trees - bad news.
-RISCH and LID TECHNOLOGIES: This is a topic I haven't breached because it is opinion, but it should be voiced. DON'T TRUST HELMETS MADE BY SKATEBOARDERS! they may look good, but they have not been tested. The guys behind these helmets NEED to invest in proper testing before exposing themselves to liability, and to ensure that their trusting audience isn't going to break their neck. This is a SERIOUS warning. DO NOT BUY THESE HELMETS. Pressure the manufacturers into extensive testing.
Also, I have concern for Concrete Wave for publishing ads that advocate helmet use, yet also publish articles about untested and potentially unsafe helmets (RISCH).
My primary concern about these helmets is the testing - it hasn't been done, or if it has there is no rating. The second concern is their usability. Before embarking on making my helmet fairing I read a few books on aerodynamics and my conclusion is that shoulder fairings are completely useless. Shoulders are aerodynamic on their own. In the dynamic nature of a downhill skateboarder the rider changes stances and in many situations shoulder fairings add additional surface area (increased drag if you are not in a tuck). Complicating matters is of course the fact that there are shoulder fairings. They get in the way and in the case of a crash, my prediction is that before long we will see broken collarbones as a result of these shoulder fairings.
What I did glean from my aerodynamic studies is that on Aero Helmets the tail fin is adding a significant amount of benefit. In the case of aero helmets this is a fixed composite construction. This concerns me. In event of a crash we do not know what outcome this will have on the rider. The fact that most helmets on the market for virtually EVERY sport allow the neck to move in the event of a crash is testimony that fixed tails are a bad idea.
My SOLUTION: For the fairing I used a piece of snowboard P-Tex because we have a lot at the shop and it fit my safety requirements. This was used because if taped on it will crush in the event of a crash, leaving the helmet to take any impact. I made 3 revisions to the fairing before it worked really well for me and as a comparison test I have ridden a LID helmet and had similar benefits speed-wise in comparision with a charly, or a Bell Drop sans fairing".
this is what he uses
thoughts?
"the charly visor fits pretty good, but needs some tape. You definitely loose some useability since you can't flip your visor up, but if you can forego looking ultra-sleek then this is the helmet.
Once you take off the visor of the stock helmet, the form factor for the bell drop is like inflating the surface area of a charly by .5" to 1" all around. It IS bigger, but it is also much, much safer. The helmet was made specifically for downhill mountain bike racing and spoke volumes to me.
When Justin Metcalf was injured, the road wasn't what did the damage, it was the trees and rocks off the side of the road. While Charly's are a great shell, and in most racing situations I believe they are safe for road impacts. It is the non-road impacts I worry about and was confronted with after Justin's accident.
So, the shopping began and the Bell Drop was what I found to be best.
To outfit it for longboarding was easy. A charly visor fits with electrical tape and the aero fairing is dead simple, but takes some revision to make it fit just right. The important thing to mention here is that the emphasis of building this helmet was to make something FAST, but very safe. The Bell drop was a starting point. Adding a visor and sealing up vents with electrical tape was step #2. The final step was really to point our that aerodynamics do not have to come at the expense of safety.
The aero helmets on the market right now have some fatal flaws that we should all be aware of:
-Paragliding helmets are made for light impacts. This is ok for road impacts, but trees - bad news.
-RISCH and LID TECHNOLOGIES: This is a topic I haven't breached because it is opinion, but it should be voiced. DON'T TRUST HELMETS MADE BY SKATEBOARDERS! they may look good, but they have not been tested. The guys behind these helmets NEED to invest in proper testing before exposing themselves to liability, and to ensure that their trusting audience isn't going to break their neck. This is a SERIOUS warning. DO NOT BUY THESE HELMETS. Pressure the manufacturers into extensive testing.
Also, I have concern for Concrete Wave for publishing ads that advocate helmet use, yet also publish articles about untested and potentially unsafe helmets (RISCH).
My primary concern about these helmets is the testing - it hasn't been done, or if it has there is no rating. The second concern is their usability. Before embarking on making my helmet fairing I read a few books on aerodynamics and my conclusion is that shoulder fairings are completely useless. Shoulders are aerodynamic on their own. In the dynamic nature of a downhill skateboarder the rider changes stances and in many situations shoulder fairings add additional surface area (increased drag if you are not in a tuck). Complicating matters is of course the fact that there are shoulder fairings. They get in the way and in the case of a crash, my prediction is that before long we will see broken collarbones as a result of these shoulder fairings.
What I did glean from my aerodynamic studies is that on Aero Helmets the tail fin is adding a significant amount of benefit. In the case of aero helmets this is a fixed composite construction. This concerns me. In event of a crash we do not know what outcome this will have on the rider. The fact that most helmets on the market for virtually EVERY sport allow the neck to move in the event of a crash is testimony that fixed tails are a bad idea.
My SOLUTION: For the fairing I used a piece of snowboard P-Tex because we have a lot at the shop and it fit my safety requirements. This was used because if taped on it will crush in the event of a crash, leaving the helmet to take any impact. I made 3 revisions to the fairing before it worked really well for me and as a comparison test I have ridden a LID helmet and had similar benefits speed-wise in comparision with a charly, or a Bell Drop sans fairing".
this is what he uses
thoughts?
Tags: Aerodynamics, Helmets, Safety
Views: 1285
Replies to This Discussion
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Premium MemberPermalink Reply by Dani on -
Nice, You will feel the speed difference straight away!
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Permalink Reply by nick on
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I have the same helmet as him so i might give it a try.
I was thinking duct tape and thin cardboard.
I also have some foam for the structure inside.
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Permalink Reply by trikes on
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Whats Grayham Rayne's qualifications as to be able to offer advice on helmets?
As I move ever closer to the expensive testing arena for helmets suitable for luging I view with caution some of his opinions. As for broken collar bones. The energy needed to brake a collar bone needs to come from basicly two directions as has been explained to me by specialists. A sharp blow to the collarbone itself will be mostly protected with a Reisch (did I spell that right) type of lid. Yet very little can be done for someone that absorbs energy throught the shoulder like falling sideways for example. So in that case shoulder / arm padding is a good idea but it lends itself to adding frontal area - hence creating more drag. So it's a catch 22, where does an individual stop / start padding themselves up.
I understand why there isn't more crush / impact testing done. To produce Standards Approved Helmets is indeed an expensive nightmare. But either the wearing of any lid in sound condition is far far better than no lid at all and wearing a spine protector will hopefully prevent someone from ending up in a wheelchair. ............trikes
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Permalink Reply by pete on
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I have been looking at that one for a long while. Good enough price etc, btu I just don't know. It doesn't look like it is one piece, and therefore does not look that strong. i am tempted though. Any opinions?
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Premium MemberPermalink Reply by Steve on -
I have never seen a helmet like that. two piece? Looks dodgy to me. Maybe try do some research on it, but if it was my head I'd use something else. How much is your head worth? I really like mine so I don't mind spending the $$$ for quality. Graphics don't look that good with bits of brain and skull splattered all over them
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Permalink Reply by John Fox Williamson on
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I was watching 'Top Gear' on TV last nite and I suddenly realised I wanted a black version of STIGS helmet... watch out here comes the mysterious ace speed test rider for the all new show on SBS ; 'Top Skate'
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Premium MemberPermalink Reply by charlie harris on -
has anyone tried 661 helmets?
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Permalink Reply by A E-B on
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ive got 1. seems pretty good. ive seen quite a few people with them. there a good price as well
charlie harris said:has anyone tried 661 helmets?
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Permalink Reply by Myles Borchardt on
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i got a 661 full comp, its a pretty good helmet. I crashed in it not long ago and it broke my sternum from the chin piece and i also received whip lash. But in saying that if i didn't have it on i can guarantee you i wouldn't be typing this. I recommend it, its a beefy, strong helmet.
charlie harris said:has anyone tried 661 helmets?
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Premium MemberPermalink Reply by charlie harris on -
im trying to decide between a 661 comp II and an Rjays Dakar
thoughts?
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