The Secretary of State for transport has the power to put in place regulation as to how a helmet must be worn. These regulations have not changed since 1998. The specification of a helmet is set by EU regulation which is not demanding. So long as the helmet meets these tests, it is legal. As there are no regulations which criminalise wearing a helmet ‘flipped up’ in my opinion means no offence is committed. However, if told by a police officer to close a flip up, I would. The police officer does have a wide range of powers including confiscation if he believes an offence is committed. He would certainly have an arguable point, which probably would fail, that the helmet only passed its EU testing whilst locked down and use on a motorcycle in a state where it had not passed its type approval could constitute an offence. Unless you have an obsessive desire to prove the police wrong, it is probably best to shut down.
But is it wise to ride flipped up? A flipped up helmet is a risky proposition and a lot riskier than an open face helmet because the rotational forces of the chin piece being forced round would be enough to cleanly snap a human neck. A helmet like the Boxer which can have the chin piece flipped right out of the way is a much safer bet. But if we wanted to be safe we’d never get out from under the duvet. 1 have ridden with a helmet flipped up. I know the risks and do it as little as is practicable.
But if you were to be hurt in a way which was made worse by riding with your helmet flipped up, how much difference would it make to an award? Let us consider a catastrophic case of a young man paralysed from the neck down as a result of the rotational forces going through the neck caused by the flip up part twisting and levering the poor guy’s neck. My opinion, untested by any court, would be that a hard Court might find 10% blame, the same as an unbuckled helmet but not the 20% usually found against drivers who do not use a seatbelt. I think it would be fairly finely balanced between the Court finding no contributory blame and 10%. If the injury was unaffected by the helmet, then there would be no reduction at all.
So do flip ups fail in crash situations? Well, as a firm we have dealt with around 15,000 motorcycle claims and I have never come across any flip up failing. As with all things, it is analysis of your own risk to benefit. The law does not do your thinking for you. If you want to ride flipped up, the legal consequences are unlikely to be significant.