(I'm choosing not to quote the individual posts, as that would send each poster a notification which increases the likelihood that we'll end up regurgitating dormant discussions. I've stated the page number so you can find them.) The following posts in this thread have questioned whether helmets provided any benefit in cases where the impact had enough force to significantly damage the helmet itself. My point is that Joe Public would read this type of thing and say "what sort of person would not strongly prefer a helmet to a bare head when being exposed to such a high impact?" which detracts from your credibility and distracts from the very strong argument that can otherwise be made against mandatory helmet use:
“And you got concussion anyway, which is a failure too. So the helmet could have provided some benefit, but the evidence is far less impressive than if neither of those things had happened. And it also fits with no benefit at all.” Page 2. 7th post, made in response to someone recounting their experience of an off-road impact with a metal post which resulted in their helmet being smashed in two.
“Until you remember that all except a few full face MTB helmets are only tested for standing falls onto flat surfaces or kerb edges. The old test of falling onto a stone has gone. Other things like typical rough surfaces have never been tested. And if a helmet hits something like a stone, or walnut, it may well fail and split. Just as well none of the helmets talked about here split, isn't it?” 2nd page, 9th post, made in response to my assertion that the helmet’s role in the above accident was clearly better than nothing.
“I see a LOT of pictures of cracked helmets - so remember this is barely absorbing any energy at all. Think of car CRUMPLE zones - they are not made out of brittle materials, deliberately!” You, page 8, referring to the same incident whereby the helmet smashed after impact with a metal post.
“I'll try to put this simply; if you crack a protective helmet, it has not reduced* the decelerations involved. It is not crumpling. A thick cushion would be better protection. In fact thick cushions would be good protection for your head against blunt trauma, even though I haven't seen any tests for me to quote at you
*Or perhaps only negligibly!” You, page 8“You can flash your credentials all you like: I do know how energy conversion works (you're not the only cyclist that went to school my friend), and I know that a cracked helmet isn't doing a lot for you.” You, page 10.
