I can remember this argument raging many years a go, when the cheap polycarbonate helmets started filling the shelves in the UK.
After destroying a couple of fibreglass helmets I decided to give the new plastic lids a try.
5 years later people were saying the Polycarbonate lids were degrading due to sunlight & the glue used on the stickers. So to be safe I decided to go back to fibreglass, but rather than just throw the old poly lid away I would conduct my own tests on it.
Test 1. I placed the lid on a concrete base & hit it as hard as I could on the top with a 10lb sledgehammer.
Result. The hammer disappeared almost into orbit, and the lid had a small mark.
Test 2. I placed the lid on its side & after finding the sledgehammer in a neighbour’s garden I tried again.
Result. Another small mark on the lid & more searching for the hammer.
Test 3. Run over the lid with a car.
Result. Plenty of scratch marks but still the outer shell was in one piece.
Test 4. Hit helmet with pickaxe.
Result. Pickaxe skidded off helmet & cracked the concrete, while the helmet was sent skidding across the car park. But still no penetration of the outer shell.
After telling a friend of my basic heath Robinson test results, he asked me if I could do the same with his old fibreglass helmet, this was only 3 years old.
Test 1. Lid placed on concrete base & hit with sledgehammer.
Result. Large hole in top of helmet, the fibreglass shattered where the hammer made contact & the lining absorbed the rest of the impact.
Unable to conduct any more tests due to only having one fibreglass helmet.
Now I know these tests are not very scientific & I’m sure helmet manufactures have far more stringent testing, but this put my mind at rest over the plastic lid row.
Another thing to bare in mind is, these helmets are designed to work in different ways. The fibreglass helmet uses the outer shell to absorb most of the impact, and in an accident will show a lot more battle scars. Where as the polycarbonate helmets absorbs the impact in their lining, and may show no signs of the battle. (Don’t be fooled by the lack of external damage, as with all helmets if they are involved in an accident they have to be changed)
The most important thing with helmets has been stated already they MUST fit you properly, & not just look good.
In the end you pay's your money & take's your choice.
Me i'm back with the Poly lids now without any worries.