Giro Radix MIPS Review

Giro has a long tradition of designing high-end mountain bike helmets, and more than any other helmet in their current lineup, the Radix MIPS reflects that heritage in its design. A descendant of classic trail helmets like the Xen and Hex, the Radix is a modern take on an iconic shell shape. In a market where helmet styles have become ultra-specialized for specific disciplines, the Radix is a true all-arounder, and for that reason we love it.

Performance Comparison

Protection

The Radix MIPS doesn't offer the same coverage and heft as a full-fledged enduro half shell, but it provides ample protection nonetheless. The shell shape sits a little bit higher on the head than its pricier siblings the Montaro and Manifest Spherical, but the EPS foam still drops down relatively low in the rear and at the temples for some added protection over a standard road cycling helmet. Despite the slightly reduced coverage, donning this helmet gave our testers the all-important sense of security and confidence that we look for when heading out onto the trails. Luckily we didn't get a chance to test it out in an impact while ride testing, but the EPS shell feels incredibly planted on your head, meaning we weren't concerned about the shell slipping out of place in a crash. Giro's Roc Loc harness system continues to be one of our favorites for its security and comfort.

As you might expect with a mid-range offering, the Radix doesn't offer the same protective technology as Giro's top-of-the-line models. Rather than using a dual-density EPS shell and MIPS Spherical like our Editor's Choice, the Manifest, the Radix uses a traditional in-molded EPS and polycarbonate shell with a plastic interior MIPS liner to help mitigate rotational impact forces. While it isn't cutting edge technology at this point, we're hugely appreciative that rotational impact protection has trickled down into mid-range offerings like the Radix. Just a few years ago MIPS systems like the one included with the Radix MIPS came at a premium.

Comfort

At this point, we've come to expect quality and comfort from any Giro helmet we test, but despite our high expectations we were genuinely surprised at this model's comfortable, secure fit when we first tried it on. Many times even the best models can take some getting used to before you're fully confident in the fit, but the Radix MIPS almost seems to pop into place on your head and feel as natural as a baseball cap. With the harness tightened appropriately the shell sits firmly in place without any pressure points or pinching, and the adjustable ear splitters manage the straps well and keep them away from your ears. Obviously, the fit will vary slightly for different head shapes, but we had a number of testers as well as friends and family try this model on with positive feedback across the board.

A confidence-inspiring fit is great, but it means nothing if the helmet starts to chafe or develop pressure points over the course of a long ride. We weren't surprised to find that the Radix stays comfortable no matter how long you wear it. During testing, we wore this model out on a few long-haul adventures and never had any issues. We actually found that all-day adventure riding is this helmet's bread and butter. The light weight and comfortable fit mean it tends to disappear on your head. Our only ask would be for a little bit more ventilation on hot days.

Ventilation

Despite a whopping 25 air vents and internal channels in the EPS foam, we found the Radix MIPS left us wanting slightly in the ventilation department. It isn't a stifling helmet by any means, and among similarly priced helmets it performed well. Given its lightweight construction, though, we expected it to be a little bit breezier. On warmer days at low speeds the air starts to feel a little bit stagnant under the hood and things can get sweaty. Our leading theory is that the small vents just don't allow as much air to move through the shell and across your head, but we would be lying if we claimed to be experts in aerodynamics.

No matter how good a helmet's ventilation is, you're going to start sweating eventually. It can be annoying and dangerous to have sweat dripping out of your helmet and into your eyes or eyewear, so we pay very close attention to sweat absorption alongside ventilation. The Radix MIPS has ample padding along the brow that does a great job of absorbing sweat and channeling it away from your eyes. While testing this helmet we didn't often find ourselves having to stop and clean salt streaks off of our sunglass lenses.

Features

As you might expect from a mid-range offering, this model isn't loaded with all of the latest and greatest features and gadgets. It does, however, offer all of the basics required of a daily driver mountain bike helmet. The already-discussed Roc Loc harness, MIPS rotational impact protection, and adjustable ear splitters make up the bulk of the Radix's feature package along with a light-duty adjustable visor. The visor isn't nearly as substantial as many modern mountain bike helmets, but it will help protect your face from light brush on overgrown trails and keep the sun out of your eyes when in the lowest position. Giro claims that it's possible to stow goggles on the front of the helmet with the visor in its highest position, but we tried it out and we wouldn't recommend it.

Without many bells and whistles, the Radix didn't force us to wade through much marketing fluff to figure out what kind of value it really brings, and that's a big part of why we found it so charming. Simply put, it's a mountain bike helmet, and it does the job nicely.

Weight

A lack of frills certainly contributes to this helmet's almost-ridiculous weight. At just 360 grams for our size large, it is among the lightest mountain bike helmets we've tested. In our minds, the Radix's weight is one of its biggest selling points. Typically when it comes to cycling equipment, weight reduction comes at a premium. The lighter the gear, the higher the price. So a lightweight helmet at a mid-range price without sacrificing quality is an exciting prospect.

Durability

Over years of testing, it has become apparent to us that Giro knows how to make a quality, durable product. The Radix MIPS is a well-thought-out package without much of a weak point that we can find and we expect that with proper care it will last as many seasons of riding as you can manage without a head impact. The harness system and straps are firmly anchored into the EPS foam, and the polycarbonate outer shell wraps around the lower edge of the EPS to avoid damage in the inevitable drops and poorly thought-out packing schemes that make up a helmet's lifespan. Our only real durability concern with the Radix is the less-than-substantial visor, but its flexibility should allow it to survive brushes with trailside branches and the garage floor well enough without cracking or breaking off.

Value

If you're looking for a versatile, no-frills mountain bike helmet that you can use for all of your cross country, trail riding, and light-duty all-mountain adventures the Radix MIPS is an excellent choice. For a price that is less than half of the top-rated models in the test this helmet stacks up well, and for that reason, we've named it our Best Buy.

Conclusion

In a world where each new mountain bike helmet release has a longer marketing brief than the last, the Radix MIPS bucks the trend. Rather than piling on a long list of features with questionable value added, Giro designed a basic but well-executed helmet with just the necessary trappings to get you out on the trails in comfort, style, and with peace of mind.