Impact Speed

[david k]

Yes but not necessarily any useful protection. It could be a minor cut saved. The person's head might well have been fine without the helmet. We just don't know.

You dont know, and therefore it wouldn't be appropriate to say it didn't offer protection

 

[david k]

It's a good job that no one has done that then. I'll repeat it once again, no one is saying that it offered no protection at all.

So to summarise:

• 5 appear to be of surface damage only; So saved surface damage to the head
• 3 appear to be damaged by crushing (typically minor); So worked as designed
• 13 appear to be complete write-offs. Worked differently but did offer some level of protection (Adrian post 117)

So according to your records helmets offered some protection 100% of the time

 

[Little yellow Brompton]

did you see the snell report attached to the block graph.

"Principal Investigator: Frederick P. Rivara, MD, MPH;"

 

[srw]

Is that a valid sample size?

Probably not - although the conclusions are striking. Call it a preliminary study to test research methodology. The same method could be used by someone with more than a half-hour lunch break on a larger sample.

 

[srw]

Lots of assumptions in your post.

How do you know that the helmets that suffered surface damage saved surface damage to the head?
How can you be sure that the write offs offered some level of protection? All the people who were wearing those might have been killed...

And there is graph in the Snell study which shows that write-offs are very strongly associated with serious injury.

 

[david k]

Lots of assumptions in your post.

I've made no assumptions, I've simply tried to summarise previous findings and posts

How do you know that the helmets that suffered surface damage saved surface damage to the head?

On balance its reasonable to expect a helmet that has scratched to have saved a head from the same, how is it possible that a helmet would scratch but a head wouldn't?

How can you be sure that the write offs offered some level of protection? All the people who were wearing those might have been killed...

I was going off Adrians advice here, when asked if they offered protection he answered "Yes...."

He did continue with "but not necessarily any useful protection. It could be a minor cut saved....we just dont know"


So we dont know if they offered a lot of protection or a small amount of protection, so in summary in all cases they offered some protection according to SRW and Adrian.

 

[theclaud]

On balance its reasonable to expect a helmet that has scratched to have saved a head from the same, how is it possible that a helmet would scratch but a head wouldn't?

Helmets make your head bigger. A lot bigger. They make people look like giant mushrooms. It is quite possible that, when you hit or scrape your helmeted head on something, a smaller, unhelmeted head would not have hit it at all. If you were wearing deely boppers and they got caught in a tree, would you assume that they had protected you from getting your head caught in the tree?

 

[david k]

With regard to the scratch, so what? Would you really wear one just to avoid a scratch? If so, I take it you similarly wear body armour?

With regard to some protection, you are clutching at what might well be straws here. This protection could be as trivial as the scratched head or it could be more, we don't know. What we do know is that it is not as much as the owner paid for. Not as much as the helmet is supposed to be rated to.

as you keep saying.. you dont know

 

[david k]

Helmets make your head bigger. A lot bigger. They make people look like giant mushrooms. It is quite possible that, when you hit or scrape your helmeted head on something, a smaller, unhelmeted head would not have hit it at all. If you were wearing deely boppers and they got caught in a tree, would you assume that they had protected you from getting your head caught in the tree?

"it is quite possible that"

Or in other words, you dont know

 

[david k]

Except the bit which I say we do know. A helmet that has cracked with minimal compression has not delivered that which it promised.

promised? so they promise they will work in any situation?

 

[david k]

Or to turn this one around, nor do you from your helmet promoting and closet compulsion viewpoint. Without any certainty on the subject the case is unproven.

Oh dear Adrian, when backed into a corner you again throw mud to try to justify your posts against helmets


Still not answered my question asking you why you presumed the owners of the helmets found on google images claim they offered more protection than they did

 

[theclaud]

"it is quite possible that"

Or in other words, you dont know

You asked how something was possible, and I explained one way in which it might be possible. What more do you want? It's you that seems to crave some kind of mushroom-headed certainty, not me. I am very happy cycling unencumbered.

 

[david k]

You asked how something was possible, and I explained one way in which it might be possible. What more do you want? It's you that seems to crave some kind of mushroom-headed certainty, not me. I am very happy cycling unencumbered.

you did explain one way it might be possible, its important for people to realise it is not certain.

So in short, a helmet may scratch which will protect the head from scratching and in other cases the helmet may scratch when the head wouldn't have scratched. In both cases the head didnt scratch so it confirms the helmet has done its job (as far as stopping scratches)

 

[david k]

closet compulsion viewpoint..

Closet? May I refer you and any other readers back to the "your agenda" thread, and therefore there is nothing closet when its been clearly described for you and all to see, the only reason you continue with this is to try to justify your responses

 

[david k]

With regard to the scratch, so what? Would you really wear one just to avoid a scratch? If so, I take it you similarly wear body armour?
.

This wasn't in response to one of my experiences but to SRW's survey, you'd have to ask them if they would wear body armour