Impact Speed

[Licramite]

Forget G all of the standards use J and the measuement is how many J will the helmet stand before it breaks... For the record you think 100J is "Crap" ? Yet the EN single test is 90J and the Snell 110J, how wonderful do you think the Snell standard is now?

How about, they are useless, they have always been useless ( you do know how the standard came about ?) and inline with every other H&S protocol we want PPE to be the very last method and not the first one? When there are safer roads, drivers, vehicles and cycle paths , then and only then is it worth looking at PPE.

110 is better than 90.
well in the snell study only 15% of cycle accidents involved vehicles.
Ignoring G forces would be like ignoring speed - G increases the effect of weight , weight is linked to joules. a 5kg head is not 5kg impacting at 25mph.

I wouldn't class a cycle helmet as useless, they clearly work within the 60% parameter of cycle accidents which happen under 15mph.

The article I was reading about cycle helmets now I understand, helmet manufacturers are clearly looking to make helmets in the future better suited to the pro riders being designed for higher speed impacts (at the detriment to slow speed performance). of course the sudo-pro's, will jump on them (not literally) and the I would like to be a sudo-pro will get them only to find they are no good for them.

 

[Little yellow Brompton]

110 is better than 90.
well in the snell study only 15% of cycle accidents involved vehicles.
Ignoring G forces would be like ignoring speed - G increases the effect of weight , weight is linked to joules. a 5kg head is not 5kg impacting at 25mph.

I wouldn't class a cycle helmet as useless, they clearly work within the 60% parameter of cycle accidents which happen under 15mph.

The article I was reading about cycle helmets now I understand, helmet manufacturers are clearly looking to make helmets in the future better suited to the pro riders being designed for higher speed impacts (at the detriment to slow speed performance). of course the sudo-pro's, will jump on them (not literally) and the I would like to be a sudo-pro will get them only to find they are no good for them.

In your words 100J capacity is "crap" , so is 110J OK or is that 10% less crap?

You have a Velocity , you have a Mass that gives you Ke , why do you want to sidestep into G to then comeback to energy? I'm familiar with the idea of "what planet are you on?" but you seem to have taken it to another universe , one where 5Kg is not 5Kg at 25MPH , how much is 5Kg at 350MPH, or 0MPH?

"Clearly"? Where is the clearly? I've no idea where you get your 60% from , but if you are using the 100J figure, don't forget ( If you ever bothered to find out) that the 100J figure is onto a flat surface, how many of your 60% are flat surefaces accidents? Do you know what the kerbstone test J pass figure is?

 

[benb]

ben, are you having a laugh? i didn't claim that or didn't mean it to read that way and have cleared that up several times, then you go on and ask the same question again!
in the second case wearing of a helmet made no difference, is that clear enough or will you ask the question yet again?

No, that's fine. It didn't appear to me as though it had been cleared up, hence why I was asking.

 

[Licramite]

its clearly 10% less crap !
may I suggest you read back through the posts and you will see were i got it from.
G forces.- it's in one of my posts further back about page 3? maybe 4. a report by I think american stock car racing authority nts on that.

I appreciate their are other tests - your point is?

Ps if you want a laugh read back further and you will see me make a complete arse of myself over bullet trajectory - boy when I get it wrong I really get it wrong!

 

[david k]

No, that's fine. It didn't appear to me as though it had been cleared up, hence why I was asking.

Glad we sorted that, sorry if i got frustrated