I make no apology for admitting a certain degree of bias here. I've worn Arai helmets almost exclusively since the first Supervent appeared on the UK market over twenty years ago. It may well be because I have an odd shaped head, it may be psychological or it may simply be that Arai liners fit me better than anything else. Whatever it is, I'm more confident, more comfortable and more at home in an Arai than any other lid you might suggest. In fact I have worn one helmet more comfortable. But it took a technician an hour to adjust it to fit perfectly, was worth thousands of pounds and, though bulletproof and fitted with the best comms kit Her Majesty's Government could buy, wasn't road legal. Hell, it wasn't even full face!

A new Arai is a special experience. Open the box and savour the smell. Look, touch, feel the mirror smooth outside finish and the soft velour inside. Marvel at the simplicity of a design that is now over ten years old but works as well as it ever did.

Then wonder why they've never updated it.

The model designation has changed and, about five years ago, the visor changing mechanism got improved slightly to make it a little less of an ohmyGodI'vebrokenit moment whenever you took the visor off. But that's it.

So what have we got here?

We've got the top of the range Arai helmet. The pinnacle of cranial protection beloved of top line racers everywhere. The RX7XX Corsair is a full face helmet made of composite materials. It has large ducts on the top which allow both air intake and extraction along the crown. And there is another vent in the chinpiece, a further one on the top and two eyebrow vents in the visor. The strap has a traditional double-D fastening and there is an exhaust vent at the bottom of the back along with two others slightly higher up. The net effect of these vents is that the helmet never gets stuffy, can always offer enough draught to keep your head cool, even on the hottest days and is reasonably fog free. Yes, these holes and channels really work. Unfortunately, as any fluid dynamicist will tell you, vents and protuberences create turbulence which creates noise.

The Arai Corsair is one of the noisiest helmets I have ever worn. It really does make earplugs a necessity, even if they weren't already, as anything approaching the legal speed limit is quite uncomfortable. The noise isn't a problem, or at least it wasn't to me, as I found the benefits of all those vents far outweighed the problems, and I wear earplugs anyway. But if you're earplugaphobic or have a particular issue with background noise then it's something you should bear in mind.

A major plus is that everything is replaceable. Inner padding, comfort lining, breath deflector, side pods, the lot. Just the shell, foam lining and strap remain in place for the life of the helmet. And being able to change all the padding means that you can tailor the fit to your precise needs, even making it off centre if you have a really odd shaped face.

This isn't the lightest helmet on the market any more. Progress has moved on and there are cleverer, lighter composite lids around. But it's still at the respectable end of the scale and the complex laminate construction is incredibly strong. I've now had the opportunity, if that's the right word, to test no less than three of these helmets in action. In fact, every RX7XX I've owned has been replaced after being bounced down the road with my head inside it.

The fact that I am merely a bit daft and not a lot dead says a great deal for the integrity of these helmets, as well as for the state of my account with Lady Luck. Though I have left at least one of them with eggshell like crazing and a large dent in the shell, not once have I even been knocked out. That speaks volumes about not just the shell strength but the design of the lining and padding as well.

I'm just about to buy my fourth. Which brings me to the only real biggest criticism I can find. Actually, there are two, but one is easily fixed by the owner.

The designs on offer are rather limited at this end of the range. Further down you can get all sorts of exciting replicas, flag designs and so on, but at this end the choice is somewhat restricted. No matter - buy a plain one, save a few quid and get it painted to your own design. That's what I'll be doing.

But the real issue is the price. For a ten year old design, even one as good as this, £450 is a heck of a lot of money. Add another £50 for a replica design and you're getting silly. There are certainly helmets around that price which are at least as good - maybe lighter, more modern, sexier looking or with even more celebrity endorsements.

But I know what I'd rather have my head in when it comes to the crunch, which is why I'll be sending my hard earned off to my local Arai stockist in the next day or two.