Damaged helmets - and using them again

Did some research into lids when getting back into biking and found out some useful stuff....

The outer lid is just for grazing or massively hard pointed impacts. Majority of head injurys result from the g force of your head inside the lid going from Xmph to stop. The inner padding is what lessens that impact - its got little to do with the outside shell, that just there to stop it all splitting like an egg.

So... if you drop your helmet with nothing inside it onto the floor, its only going to damage the outside shell as nothings hitting the inner shell so its prolly ok to wear again, regardless of scuffs and scrapes on the outside. However any bang with a weight inside the helmet, could be your head, could just be a pint of milk inside your lid, that will impact the inner lining and significantly reduce its ability to reduce gs next time. Think of the inner lining as a 1 off shock absorber basically, like styrofoam that is squeezed.

Judging by the state of that helmet, I wouldnt wear it and think it was safe, on track or road. Really hard to tell if the helmet did only graze the ground when you crashed or your head was cushioned from it by the inner lining but has now degraded that lining.

hth

[fastdruid]

Originally Posted by dizzyblonde

You'd be surprised at how many helmets the same size are completely different. I've gone through a shop full before finding the right fit.
My new lid is the same make and model as the old one, but different design too, but for some reason I had to go away with a size smaller
IIRC all the outer shells are all the same in their particular size, its down to all the padding that make them all so varied.

The previous ones were AGV X-Vents as I'd previously had an X-Stream and the X-Vent was the model up, mine was this one


Hers was this one


Totally identical when bought we both tried both then agreed on the paint job we preferred.

When it came to a replacement tried *loads*, thought as I'd got on with AGV previously would try the (new) AGV but didn't like it. Ended up with a Ti-Tech instead.

Druid

[yorkie_chris]

Originally Posted by G

mainly a momentary grazing once I was already sliding along the ground.

Probably fine then.
Question is your acceptable risk.

given your account of how the damage occurred, I'd probably use it.

[yorkie_chris]

Originally Posted by dizzyblonde

In a nutshell, its not the outer shell you need to worry about, its the inside materials that are damaged on impact.

Basically the polystyrene foam inner lining acts like the crumple zone in a car. You need the lid to absorb the force of an impact.

If your head hits the deck hard enough for the foam to do owt, you know about it. My caberg hitting the deck sounded like a building collapsing from inside it.

Speedplays suggestion is a great idea, give to an ambulance or fire station. They can be invaluable for practice. Certainly when I did my training again the other week we did it at a fire station and didnt really have enough helmets for everyone to have a go. I was lucky enough to get a go.

[BanannaMan]

If the "crumple zone" effect of the helmet inner liner worked as intended it's quite likely you may not realize how hard your head hit the deck.

Whilst highsiding July 2008 my HJC was the first thing to hit the deck with the full weight of both bike and rider on top. However I felt absolutely no impact to my head at all. (I did hear it smack the tarmac)
On the outside there's only minimal scratches and there is no visable damage what so ever to the inside...but obviously there has to be.

Given you already have another.....Is it really worth the risk to wear this lid?

Also consider the likelyhood of landing on the same spot on the helmet in a future off. Is the shell going to survive that much abrasion in the same location.

It's done it job mate. Toss it in the bin.
(or donate it as others mentioned)

Don't use it again... except to wear while playing racing games on the Xbox for added 'realism'. Indeed, buy a knackered old headset from Blockbuster and wire it up to the helmet so you can still call people fagorts whilst racing

The only way to be certain would be to get it inspected by the manufacturer - the Arai I was wearing that day had been previously adjusted, but I got it checked out and they gave it a clean bill of health.

If that isn't possible, then I'd go with the donation idea in case I needed the next one removed for me.

Originally Posted by orose

The only way to be certain would be to get it inspected by the manufacturer - the Arai I was wearing that day had been previously adjusted, but I got it checked out and they gave it a clean bill of health.

If that isn't possible, then I'd go with the donation idea in case I needed the next one removed for me.

I think, but i may be wrong, Arai are the only people to offer that service, but worth an ask, there is also no such thing as a X-ray machine according to the Arai rep i spoke too

Originally Posted by Holdup

there is also no such thing as a X-ray machine according to the Arai rep i spoke too

They'll be denying God exists next I wonder what hospitals use to take pretty pictures of one's insides if Arai are right?