Bike Helmet Shell Thickness
08-29-21, 11:19 AM
#26
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 14,953
Bikes: Tarmac Disc Comp Di2 - 2020
Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 6178 Post(s)
Liked 4,796 Times
in
3,308 Posts
The fact that a bicycle helmet shell is "designed to slide on the ground", does not suggest nor imply that this is it's sole, or even primary purpose.
A bicycle helmet will not slide on many surfaces such as grass, and at an acute angle of impact, will not "slide" on tarmac, either.
Construction helmets are not designed in anticipation of any colliding object "sliding off". They are made of impact-resistant materials.
It is counter-intuitive to suggest that the shell plays no role in impact resistance/dissipation.
https://www.explainthatstuff.com/how...mets-work.html
A bicycle helmet will not slide on many surfaces such as grass, and at an acute angle of impact, will not "slide" on tarmac, either.
Construction helmets are not designed in anticipation of any colliding object "sliding off". They are made of impact-resistant materials.
It is counter-intuitive to suggest that the shell plays no role in impact resistance/dissipation.
https://www.explainthatstuff.com/how...mets-work.html
08-29-21, 12:04 PM
#27
Standard Member
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,257
Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1294 Post(s)
Liked 935 Times
in
487 Posts
Wrong, Iride01:
Milton Keynes: "There really is no protecting of the foam," "...the plastic shell is not there to protect the foam. It's to allow the foam to slide on the pavement."
Milton Keynes: "There really is no protecting of the foam," "...the plastic shell is not there to protect the foam. It's to allow the foam to slide on the pavement."
08-29-21, 01:11 PM
#28
Senior Member
Join Date: Jun 2005
Location: Kentucky
Posts: 2,599
Bikes: 06 Lemond Reno, 98 GT Timberline mtn.bike
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 426 Post(s)
Liked 699 Times
in
436 Posts
It's a fine line when it comes to the exterior of a helmet. You want it to absorb impact, not be so tough as to bounce your head around should you happen to land on it. Extreme example--at one time, I worked in a motorcycle shop. One of our competitors was offering a free helmet with a motorcycle purchase. We kept one of those free helmets for demonstration--never had to give it away. The demonstration of that helmet was to hold it overhead and slam it to the floor. Then it bounced back up. Whereas, if you took a good helmet and did the same thing, it would remain on the floor. Might crush like an eggshell at the impact point, but wouldn't snap your neck bouncing back! Yes, it's an extreme example, but the principle is the same. You don't want a thick exterior shell, it should absorb impact, not transfer it to your head.
Likes For freeranger:
08-29-21, 01:38 PM
#29
Tragically Ignorant
Join Date: Jun 2018
Location: New England
Posts: 15,613
Bikes: Serotta Atlanta; 1994 Specialized Allez Pro; Giant OCR A1; SOMA Double Cross Disc; 2022 Allez Elite mit der SRAM
Mentioned: 62 Post(s)
Tagged: 0 Thread(s)
Quoted: 8186 Post(s)
Liked 9,098 Times
in
5,054 Posts
There are multiple different designs for bike helmets at this point, some of them using plastic gels instead of foam, and others use plastic shells as structural support of the helmet. But the thin-shelled helmets pretty much use the shell for the friction reduction and, let's be honest, esthetic reasons. What people are objecting to is your intuitive assertions that this can't be right. Thin-shelled helmets are safe, certainly for road bike use. If you'd rather pay more money and/or wear a hotter helmet, feel free to choose a different design.
08-29-21, 01:51 PM
#30
Tragically Ignorant
Join Date: Jun 2018
Location: New England
Posts: 15,613
Bikes: Serotta Atlanta; 1994 Specialized Allez Pro; Giant OCR A1; SOMA Double Cross Disc; 2022 Allez Elite mit der SRAM
Mentioned: 62 Post(s)
Tagged: 0 Thread(s)
Quoted: 8186 Post(s)
Liked 9,098 Times
in
5,054 Posts
Hypothesis- With a good whack, the styrofoam can break apart.
Methods-I've cut and peeled the outer plastic off an old helmet and whacked it with a bat. Styro broke apart. Whacked another with the plastic intact, helmet stayed together. Both cases 10+ year old helmets were wrecked.
Conclusion- outer plastic good.
Methods-I've cut and peeled the outer plastic off an old helmet and whacked it with a bat. Styro broke apart. Whacked another with the plastic intact, helmet stayed together. Both cases 10+ year old helmets were wrecked.
Conclusion- outer plastic good.
Conclusion --that sounds like you had fun. It's a hell of a sample size and set of controls far from proving anything.
Any other old stuff you want to hit with a bat? This could be a good YouTube channel.
