How do i make a bicycle helmet larger?

It doesn't fit my head. Should i sand it with my dremel? I don't have anymore cutting wheels.

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kelseymh8 years ago
I would recommend strongly against doing that. Bicycle helmets are made with pressure-formed styrofoam. They protect your skull by "absorbing" the momentum of impact. That happens by having the styrofoam get damaged (it cracks, the grains separate, and so forth) rather than your head doing so. If you "pre-damage" the styrofoam by doing what you suggest, it will be less able to absorb an impact.
Yerboogieman (author)  kelseymh8 years ago
So that is worse than not wearing a helmet?
It's not worse, except to the extent that you assume you are being protected, and therefore behave more dangerously than you might without a helmet at all.
P.S. This is why you really should get rid of a helmet (or at least not use it for safety purposes) if you've been in an accident. Even if the outer plastic shell looks fine, the styrofoam core may (and should!) be broken.
It's almost a shame they're designed to critically break...not just absorb and spring back like a very firm memory foam. Granted - in the types of force involved in a crash you pretty much need a very hard foam... I'd rather have the helmet break than me.
Re-design8 years ago
If you alter the helmet and then get hurt, your case in the law suit will really be damaged by that fact!
Kryptonite8 years ago
Well firstly it's dangerous, but that's already been covered. And secondly, because it's made out of a specially formed styrofoam then it's hard to increase the size and keep the actual purpose of the helmet; safety. I guess if you were doing it for looks you could fibre glass the outside and hollow out the inside.
novakfor38 years ago
Like kelseymh said, it is very dangerous. You could actually make the bicycle helmet dangerous by modifying it.