Dropped helmet

[Aitch]

Nope I didn't drop my helmet, but I have a question on this very topic. When I did my defensive ridong course a long, long time ago, the instructors stressed that if you drop your helmet, even once, onto a hard surface it's time to toss it out and get a new one. Now, helemt technology must have improved since the early eightys, but do you still discard a dropped lid????

[deathstar]

depends what height really and how much you think you need your head ... generally anything above 4 feet onto a solid floor then yeah you could of fractured the lining ... can't really tell from the outside but means your helmet will be worth nothing to you in a crash but yeah depends on how it hit and from what height

[Mully]

I concur. For what it's worth.

[McJim]

It does depend a bit on the type of lid - have you tried the coin test?

Tap a coin lightly around an undamaged part of the helmet then keep tapping the coin, listening carefully, and move to the area of impact. If the lid is cracked or the composite layers are compromised then you'll hear a different tone.

To be safe I would always buy another lid though - buy cheap lids if you plan on dropping them all the time though

[SpinFx]

Tricky question that........ I find it similar to.....Do I need insurance......
Most of us hope we never need protection but when we do it's good to know it's there.

[Dave Lobster]

Think of it this way... you fall off your bike and your head hits the floor.. you skate along the road a bit.. and bang your head on a wall. Is your helmet going to be useless for the second impact?

[Dave Lobster]

whoops.. pressed the button twice

[vifferman]

Depends on the helmet, and how it drops.

Bear in mind a helmet has two main parts: a shell, and a lining. The shell is mainly for protection while the lining is for impact absorption: it compresses to slowly decelerate the skull.

If the shell's polycarbonate ("injected resin") then a drop won't affect either the padding or the shell (apart from chipping it), as the shell is designed to withstand impacts without the integrity being compromised (i.e., without being fractured).

If, however, it's fibre-reinforced plastic of some sort, the helmet is designed to absorb some of the initial impact in the shell and the drop could compromise the shell's integrity. Once again, the liner will be pretty much unaffected, as there's no noggin inside to be decelerated. If the shell has been weakened, more than likely there will be some external evidence, such as chipping or cracking, and tapping or pressing the marked area shouldl reveal weakness in this area.

If you've only dropped your helmet (and didn't have a head inside it), and there's no detectable damage, then give it to me. My brain's broken, so I can wear only helmets that are valueless, so as to avoid overcapitalising my noggin.

[vifferman]

depends what height really and how much you think you need your head ... generally anything above 4 feet onto a solid floor then yeah you could of fractured the lining ... can't really tell from the outside but means your helmet will be worth nothing to you in a crash but yeah depends on how it hit and from what height

You do know that the lining is, right? It's polystyrene, with foam plastic inside that (nearest to your skull). You cannot fracture foamed polystyrene, and its job in an impact isn't to fracture - it's to compress. Both it and the foam plastic covering it are designed to cushion your head and to absorb the shock of the impact by deformation. If the lining of your helmet fractures, then somehow it's been exposed to some heat or solvent that's made it brittle.
That's why you shouldn't use your helmet as a makeshift petrol carrying device, and why you shouldn't clean it with solvents.