Smith Rover Helmet - Review

The feature that truly pushed the Forefront out, er, front was its extensive use of Koroyd—a polymer honeycomb layer material that can be combined with expanded polystyrene (EPS) foam to create a kind of dual-density helmet liner, which, theoretically, should provide cushioning for both high- and low-energy impacts alike. Smith calls it Aerocore. The Rover uses quite a bit less Koroyd in its liner than the Forefront—just a couple patches on either side of the helmet. But while the Rover has a more Spartan ethic than its pricier sibling, it does share some fundamental features, including X-Static anti-microbrial helmet padding, VaporFit adjustable retention system and lightweight, single-layer webbing. If you are all about MIPS, the Rover can be had in both MIPS and non-MIPS version. If matte charcoal isn't cutting it for you, the Rover is also available in seven other colors.


The path of least resistance, so to speak, would have been for Smith to make a less-expensive version of the Forefront, but the Rover is a truly different beast. If you want to skip straight to the testing bit of this review, scroll down for it. If you want to learn more about why Smith went this route with the new helmet (and what the deal with Koroyd is all about), check out the interview with Jon Raymer, directly below.

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Koroyd claims their honeycomb is more effective than traditional EPS foam liners at reducing energy transfer to the brain during an impact. What exactly is it about how Koroyd performs during a crash that is supposed to give it an edge over EPS?
There are a few factors that can help achieve better test results:
1) Unlike foams, Koroyd has a very linear absorption performance, e.g. you need the same amount of stress to further compress the core. Foams densify during compression and require more stress to further compress, which is less favorable.
2) Koroyd can generally compress further (percentage-wise) until it fully densifies and hence absorb more energy in a certain thickness.
3) The Koroyd core is based on thermoplastics that are much more stable in a wide range of temperatures, where the impact performance of foams is more negatively affected by cold and hot conditions.
4) Foams tend to store and rebound forces that may cause a second acceleration in the opposite direction after the impact, which can cause further damage. Koroyd collapses and has minimal rebound.


Koroyd also claims that their “thermoplastic tubular honeycomb core has proven to outperform EPS as an absorption liner material inside protective helmets, with maximum deceleration values often 25% to 35% lower than EPS”. That’s a bold claim. Have the results of Koroyd’s testing been replicated by independent testing sources?
In absorbing energy, you need to have all the elements optimized and work together. In a helmet, the shell is designed to spread the load over a larger area, so that the absorption layer underneath can minimize the forces - apart from protecting against, for instance, abrasion and penetration. To have a true like-for-like test, you require two exact helmets one with Koroyd and one with just EPS. We have tested various helmets at independent test labs with this method and achieved those reduced decelerations, compared with the EPS reference models.

Indeed when Smith first evaluated Koroyd before beginning any projects we replaced the EPS in one of our existing helmets with pockets of Koroyd in the impact locations. The Koroyd had the same dimensions as the EPS it was replacing and the Peak G (read acceleration) was reduced by up to 32%. This was without optimizing the helmet to work with Koroyd and we are now able to improve on those first results further. From day one we have seen Koroyd is able to absorb significantly more energy than EPS.

We are not claiming that any Koroyd equipped helmet outperforms any other EPS-based helmet by 25-35%. A theoretical EPS helmet with a very thick EPS liner is likely to perform very well to reduce linear acceleration.



Does Smith plan on one day launching a helmet with a liner composed entirely of Koroyd? Is such a thing even possible or do you always need to incorporate EPS?
It is possible to produce a single liner with Koroyd that can be installed inside a helmet shell, without the need for EPS. But using EPS as a skeleton and placeholder of Koroyd inserts allows us to optimize each insert for the impact zone where it is applied. For instance, a top of a shell typically has a double curvature, which creates a stiffness that is very different from the stiffness at the side of the helmet. Using separate Koroyd inserts allows us to address the difference in, for instance, stiffness with an absorption material designed to match the shell characteristics at each point.


If Koroyd is better at absorbing energy (than EPS), why not use more of it in the Rover?
As with most complete product line offerings there are different models that are tiered by features. which are typically driven by cost. The Rover is an example of this, our Forefront helmet features full-coverage of Koroyd, offering increased protection and thus a higher price point.


The Rover has a fixed visor. Why did you go that route, rather than offering a visor with some form of tilt adjustment?
Our intent was to again offer a different feature set that our Forefront helmet.





On Trail

Smith did good work with the overall fit of the Rover. How well a helmet molds to any one person’s head is always going to vary. Smith, however, ticks off the core basics with the Rover.

The Forefront’s aesthetics have always been a love or hate kind of thing. The Rover, with it’s cleaner silhouette, will likely appeal to a broader audience. There is, as mentioned earlier, less rear coverage to be had with the Rover than with most all-mountain/enduro half-shells these days. Whether or not that matters to you is a personal call. I like the sleek look, but have personally grown accustomed to having more of a foam mullet cascading down towards my shoulders.

Smith absolutely nailed ventilation with the Rover. There are very few helmets on the market that do a better job of channeling air over your scalp. The massive, sculpted vents get much of the credit here, but the lack of Koroyd also helps. Koroyd may offer a kind of enhanced energy absorption, but the mat of thermowelded straws tend to block airflow—that was always my one gripe with the Forefront.

The relatively sparse use of Koroyd here means that airflow isn’t hampered here at all. So, there’s two ways to look at the limited use of Koroyd on this helmet: If you want the maximum benefit of the material, go with the Forefront. If you ride in hot areas or are simply a fan of cooler lids, but you still want some of Koroyd’ protective value, the Rover is the better choice.


Finally, there’s the visor: Its lack of a tilt option didn’t bother me on descents. Smith’s done a good job of finding the right angle to fix this thing at. I never found myself actually wanting to ratchet the thing up when riding with sunglasses. The visor also works well with goggles in place. However, if you feel like giving the goggles a break (say on a climb), the lack of visor adjustability means you can’t perch the goggles up on the forehead section of the helmet. That’s a shame because the Rover is otherwise a great choice for goggle-loving riders; the shell’s shape meshes perfectly with goggle straps. Bottom line—a tilting visor is simply the kind of feature that should show up on any helmet at this price point.

Speaking of price point, you might notice that I’m listing a different price on the Rover than what’s been previously published elsewhere—that’s because Smith just lopped $30 USD off the sticker price for both the MIPS and non-MIPS versions. Given the recent debuts of more wallet-friendly helmets, such as the Giro Chronicle and Specialized Ambush Comp, the Rover's new price is a move in the right direction.


Pinkbike's Take:

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