Response from Limar on the safety of freezing helmets
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- July
- 29
Getting back to tips in the heat from a post two weeks ago.
Bob at ProNet who handles Limar helmets in the USA sent the safety question about freezing helmets to help your head cool to his testing labs. He clearly took Jason’s concerns seriosly saying, “Sorry for the long wait in getting back to you on your question below concerning freezing a bicycle helmet but wanted to make sure we had the correct answer so forwarded it to the experts at the Limar testing lab their reply is shown below.”
As you know, helmet standards include a frozen helmet for testing. For CPSC the temperature is -15C so we know that helmets are not damaged by exposure to that temperature. However, if you feel how quickly a helmet warms up after coming out of the freezer, I would put the cooling effect on the rider at a few minutes, not a half hour. That is because the EPS that makes up the bulk of the helmet has a very low capacity to hold heat. (which also means it has minimal ability to “hold†cold.)Freezing helmets won’t hurt them (at least at -15C) but is of trivial advantage since that’s when the riders are coolest also.
Thanks to Limar and ProNet for their diligent research and detailed response.
Below is Jason’s saftey concerns.
I will agree with almost all of the above. I will have to caution anyone trying to freeze their helmet as a means of keeping themselves cooler during a ride. Almost all cycling helmets are made of porous polystyrene utilizing either an in-mold design (plastic shell is seamless with the polystyrene) or cap design (plastic shell is laid on top and a taped seem can be seen joining the 2 together) in either case long after you have ridden with the helmet on not all of the water has been eradicated from the porous sections of the helmet, once you begin to freeze your helmet the water will expand and start breaking apart the polystyrene thus reducing the protection the helmet was designed to provide.as a former cat 1 racer with a sponsor and and almost unlimited supply of helmets this might be fine for the 1 or 2 races done with helmet that has been frozen but repeated freezing and thawing of any porous substance should be frowned upon.
This entry was posted
on Tuesday, July 29th, 2008 at 11:31 AM by Randall Wolf. 
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