Originally Posted by Wuwei
Yes, but even insulation will heat up eventually due to conduction from the black shell. So, even if air movement will mean the black helmet can remain as cool as a white helmet at speed that effect won't happen if say you're stuck in a traffic jam, or you just want to leave your helmet on your bike while you eat lunch.
Here's what we all need--something that goes inside the helmet to keep you cooler
Head skins, helmet liners and the materials in the article will certainly help.
There is one thing that already goes inside your helmet to keep you cooler. Your head. It includes a very complicated organic temperature control system that uses a variety of methods to regulate the temperature of the brain to the exclusion of many other sub-systems under certain conditions.
Manage the gear you wear to allow the temp of your body core to stay at 98.6F, coupled with proper hydration, and your head will remain comfy.
Do some research on the heat conductivity of that foam and you will find your theory to represent negligible, if not imperceptible heat gain from the outer shell.
When compared to the heat transfer by your bloodstream from the core to the head, there won't be enough heat conducting through the foam to make any significant difference in your comfort level.
On the other hand, if you are not getting enough evaporative cooling from sweating, for any of a number of reasons (hydration, air flow, etc.) your core temperature will rise.
There is also the mind over matter aspect, where if you believe that your head is hotter, your body might just do everything it can to meet your expectations.
Think cool, be cool. Ommmmmmmmm.