So what’s the deal?

Fundamentally, open-face helmets haven’t changed much since the introduction of EPS (expanded polystyrene) as the material of choice, so the 6D ATB-1T helmet is a very progressive piece of kit. This is the first open-face mountain bike helmet to use 6D’s Omni Directional Suspension (ODS) technology. Cutting past the fluff, the aim of the game here is to create a helmet that transfers less energy to your noggin in the event of a crash than any other open-face on the market, which means less risk of brain injury.

How is that done?

What we have here with the 6D is kind of a helmet within a helmet – look closely and you’ll see there are two separate EPS shells, the outer one is firmer, the inner one is a little softer. But it’s what goes on between the two shells that really gives the 6D its brain saving edge, namely the ODS system.

ODS is a series of small flexible dampers – they look like little rubber hour-glasses or buttons – mounted to two plastic carriers that are joined to the EPS shells (take a look at the pic below for more clarity). The whole system ‘suspends’ the shells, allowing them to have degree of movement independent of each other.

Why go to all this trouble?

We don’t profess to be physiologists, neurologists or even very intelligent, but here’s what we understand. We’re still learning a lot about brain injuries, in all kinds of sports, but one of the most interesting things to emerge recently is data about the energy transfer in oblique impacts (e.g. the kinds where your head hits the ground at an angle, and slides or skims, rather than smacking straight down). What has been found, is that the angular acceleration passed to your head from an oblique impact is exactly the same whether the rider is wearing a conventional (read, traditional EPS) helmet or not. And given that angular acceleration is the primary cause of concussion, it makes sense to try and mitigate this.

6D claim that their ODS system achieves this and “dramatically reduces the transfer of angular acceleration to the head forms and the brain.”

In terms of protecting you from other impacts – for instance toppling over backwards and hitting your head, or running front on into a tree – 6D claim they outperform all comers in those instances too. They say that other helmets, in order to pass high-velocity impact tests, are made too stiff and hard and therefore sacrifice absorption against low-velocity impacts. The 6D, by virtue of its dual density EPS shells and ODS, is able to offer more cushion against these low-velocity impacts, while the firmer outer shell doesn’t sacrifice protection in high-velocity impacts either. Look, we’re going to have to take their word for it here, but it makes sense to us.

How does this system differ to MIPS?

You’re probably familiar with the MIPS system, or you’ll have at least likely seen the little yellow label on many modern helmets. The ODS system is different to MIPS in a number of ways, but in essence, MIPS is a helmet liner that is designed to introduce a slip plane between your helmet and head, to reduce rotational forces upon impact. The 6D approach achieves the same outcomes (by virtue of the two shells being able to ‘slip’ relative to each other) as well as offering more compliance and energy absorption than a helmet without ODS.

Is it bigger than a regular helmet?

All that technology has to fit somewhere, so yes, the 6D ATB is probably larger and heavier than your current helmet. Our size M/L weighs 524g. By way of comparison, a Giro Montaro with MIPS is 390g in size medium.

Size-wise, it is a big helmet. But really, when you compare it to many other three-quarter coverage trail helmets (particularly thenew Fox Meta helmet, or even the Bell Super) it’s not over-the-top big.

Does it look good?

From a styling sense, yes, we think it’s a cool looking helmet. The graphics are sharp, there’s a tonne of colour options, plenty of visor adjustability, and the retention system is easy to use. Still, it is big, and the overall size of the 6D is definitely going to turn off some riders who fear looking a bit like a mushroom, but surely your safety is more important than that. And we think you’d quickly get used to it too.

The 6D will set you back $289, which is certainly on the upper end of the helmet spectrum, but we actually think it’s a pretty sharp price given the innovation and R&D that has clearly been invested here. We’re going to ride this thing over the coming weeks, and while we can’t promise that we’re going to crash on to our heads in the name of testing, we’ll be back with a full report on the comfort, fit and ride performance soon.