Originally Posted by corrado33

You can't compare it to a car. In a car accident there is so much more energy that the typically "hard" outer shell (metal body) is compressed like the soft part of a helmet would be.

The energy has to go SOMEWHERE. Your brain is STILL traveling at X MPH and STILL has to come to a stop. I actually think exactly the opposite of the way you do. If you have a hard inner liner, the liner will not conform to the head (unless, of course, it's molded to the user's head), therefore you'll get hotspots. If the liner is rigid it will STILL only compress the soft material that's in front of it. (Between it and the ground.) If you have a soft inner liner, as it compresses it contacts with more of your head and dissipates more energy (like what you were saying.) Basically, like I said before, it doesn't matter WHERE the soft material is. It get compressed regardless. It just makes a heck of a lot more sense to put it on the inside of the helmet (for comfort.) Besides, if you have soft stuff on the outside of the helmet it's more likely to get worn away (by asphalt) or torn away (by rocks/trees) than a hard plastic outer shell.

The sad truth is this. Bike helmets aren't big enough to provide adequate concussion protection in a serious bike accident. They need to be bigger. However if they're bigger no one would wear them. Hence my idea for "technology." Or rather "how to shove a bigger helmet into a smaller form factor until it's needed." Aka the airbag helmets.

Millions of dollars have gone into our current helmet design. Do you really think that if it was more beneficial to have the padded part on the outside of the helmet high risk people (race car drivers) would still be using hard shelled helmets?

And besides. If you had a "hard" inner shell, you'd need more padding to make it comfortable, essentially making a double layer, extremely large helmet that no-one would ever wear.