Alpinestars SM5 Helmet Review: A Brilliant Summer Lid for Green Laning

The SM5 is a motocross helmet, not an adventure helmet, and that makes a big difference once you're off the road. It's open, light and well ventilated, and it gives you that proper dirt-bike feel a lot of adventure helmets don't quite manage. It's what I wear when I'm taking the Voge 300 Rally down muddy lanes, including the ones I'm grading for Holloway.

Honestly, I also think it looks fantastic.

First impressions

The design is clean and aggressive without going over the top. I particularly like how Alpinestars has worked the peak into the shape of the helmet, so it looks purposeful rather than like a road helmet with a peak bolted on. That's subjective, of course, but I think they got the styling spot on.

It's light when you pick it up and, more importantly, it doesn't feel like a lump sitting on your head. Alpinestars quotes 1,350 g for a medium in the ECE version (mine's a large, and bigger sizes usually weigh a little more), and it's well balanced, so it feels lighter on than that number suggests. For green laning, that's exactly what I want.

Ventilation is the big selling point

This is where the SM5 really comes into its own. On a warm day, the difference between a conventional road helmet and the SM5 is huge. There's so much more air moving around your head.

It has multiple intake and exhaust vents, the peak helps direct air into them, and the inside is fairly open rather than padded and sealed tight around your head. It's lovely and breezy on slow lane riding, when you're stopping, picking through ruts, standing on the pegs and generally working much harder than you would on the road. You really notice it when you get back on the bike after a stop.

The downside of all that airflow is that this is very much a summer helmet. I wouldn't want to spend a freezing January morning in it. In cold weather, there's simply too much air coming through.

It feels properly at home off-road

There's something about a proper MX helmet when you're green laning. The eyeport is large and works brilliantly with goggles, with plenty of room around your eyes. It feels far more natural off-road than trying to make an adventure helmet work with goggles.

There are also small loops by the cheek pads for routing a hydration tube, which is a nice touch on longer rides. Put the ventilation, the eyeport and the open construction together and it all makes sense on actual trails rather than a commute.

What about the road?

This is where I'd put a big asterisk. It's perfectly usable on the road, especially between lanes, and it's more stable at speed than you might expect from an MX helmet. But it's still an MX helmet. It's noisier than my road helmets, there's nowhere to fit a comms unit properly, and I wouldn't choose it for a 300-mile motorway slog. That isn't what it's for.

For riding out to the lanes, a bit of tarmac between them and most of the day off-road, it makes far more sense. And earplugs are still a very good idea.

A summer on the lanes

I've worn the SM5 on the Voge all summer, and on some of the ridiculously hot days we had this year it kept my head genuinely comfortable.

The light weight makes a real difference, too. On Sandye Lane near Swineshead, where I was ducking and weaving around overgrown branches, moving my head about was so much easier with a lighter helmet on. You really notice the weight saving.

It's holding up well. The padding still feels good and soft. Honestly, I'm surprised how much I like it, given I'm usually an adventure helmet person. My one wish is that it could take a comms unit.

The fit

Mine's a large, and I've got on well with it, but the SM5 has a snug, purposeful fit, and getting it on can feel tight. It comes in several shell and EPS sizes, and the padding is slimmer than on a road or adventure helmet, though mine still feels soft after a summer of use. Helmet fit is incredibly personal, so try one on rather than assuming your size in another brand will carry over.

The strap is my biggest niggle

The SM5 uses a traditional double-D ring fastening, exactly what you'd expect on a proper off-road helmet. It's simple and proven, and I've no problem with the design itself. What I do find slightly annoying is the release. Sometimes it's a bit tough to operate. It might be my hands, but compared with my other helmets it doesn't feel as smooth.

It's hardly a deal breaker, and once the helmet's on I don't think about it. But this is an honest review, not a brochure, and it's one of the little things I'd change.

Safety and construction

This isn't a cheap MX helmet with an Alpinestars badge on it. The ECE version is certified to the current ECE R22.06 standard, and it uses a multi-density EPS liner, with different densities to manage different kinds of impact. The cheek pads have an emergency release, so they can be removed after a serious crash, and Alpinestars says the peak is designed to release at a set force in an impact rather than staying rigidly attached.

That's all stuff I hope I never test, but it's reassuring to know it's there. You'll see crash stories online about the SM5, both ways. I wouldn't put much weight on anecdotes: the current ECE version is formally certified to R22.06, and that's the bit that counts.

The peak

I really like how the peak looks and works, and its shape helps feed air towards the vents. The trade-off of that release system is that you don't get the adjustment range you'd find on some MX helmets, so you can't drop it lower for a low sun. That hasn't bothered me, because I wear the SM5 for exactly the riding where I want the peak doing its job, not being fiddled with.

Cleaning is easy

You're going to get sweaty, and mud will get into places you didn't know existed. Sooner or later the inside needs washing. The liner and cheek pads come out and go back in without a fight, and they're washable. It's one of those boring features that matters a lot more after a few proper muddy rides.

Would I buy it again?

Yes. For the job I use it for, it's brilliant.

I wouldn't replace my road helmet with it. But that's not why I bought it. On a hot summer day heading out green laning, especially riding solo without comms, it's light, airy, comfortable enough for a full day, and it gives me that proper motocross feel. And yes, a little bit of it is about looking the part. It doesn't feel like an adventure helmet that can cope off-road. It feels like a proper MX helmet, which is exactly what I'm after.