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Giro Radix Mips Review

A versatile trail helmet that will stand up to all-day adventures and won't cost you an arm and a leg
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Giro Radix Mips Review
Credit: Zach Lovell
Price:  $120 List
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Manufacturer:   Giro
Zach Wick
By Zach Wick ⋅ Review Editor  ⋅  April 25, 2025
Contributions From: Zach Lovell
71
OVERALL
SCORE


RANKED
#16 of 23
  • Impact Test - 30% 5.3
  • Comfort - 20% 9.0
  • Ventilation - 20% 7.0
  • Usability - 15% 6.0
  • Weight - 15% 9.7

Our Verdict

Giro's recently introduced Radix Mips continues their fine tradition of high-quality, mid-range offerings. It doesn't boast Giro's latest and greatest tech innovations, but this durable helmet does offer an extremely comfortable, secure fit, a light weight, and all of the basic must-have features that we expect from a modern mountain bike helmet. The ventilation leaves something to be desired when compared with the breeziest models on the market, and the trail-lid style shell doesn't provide quite as much coverage as the burlier all-mountain shell styles. Regardless, the Radix Mips was among the most comfortable helmets we tested, and we think it's one of the best values on the market. We fully recommend this lid to any trail rider who values comfort, weight, style, and functionality.
REASONS TO BUY
Lightweight
Comfortable
Affordable
REASONS TO AVOID
Less coverage than some other models
Small visor
Average ventilation

Our Analysis and Test Results

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.

giro radix mips - the radix's shell shape resembles a classic mountain biking helmet.
The Radix's shell shape resembles a classic mountain biking helmet.
Credit: Zach Wick

Impact Test


After conducting impact tests in a lab, this helmet got a middle-of-the-road score. It passed the requisite standards set by the CPSC, making it still a worthy option if you're looking for a light and modest profile helmet.

giro radix mips - the impact testing left every helmet visibly damaged, but the data...
The impact testing left every helmet visibly damaged, but the data from G sensors in the fake head offered objective information.
Credit: Matt Lighthart

Comfort


At this point, we've come to expect quality and comfort from any Giro helmet we test. However, despite our high expectations, we were genuinely surprised by the comfortable and secure fit of this model when we tried it on for the first time. 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 effectively manage the straps, keeping 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.

We weren't surprised to find that the Radix stays comfortable no matter how long you wear it. During testing, we subjected this model to several long-haul adventures and encountered no issues. We actually found that all-day adventure riding is this helmet's bread and butter. The lightweight and comfortable fit means it tends to blend in with your head. Our only ask would be for a little bit more ventilation on hot days.

giro radix mips - this option offers excellent all day comfort.
This option offers excellent all day comfort.
Credit: Zach Lovell

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.

The Radix MIPS features ample padding along the brow, which effectively absorbs sweat and channels it away from your eyes. While testing this helmet, we didn't often find ourselves having to stop and clean salt streaks off our sunglass lenses.

giro radix mips - despite the number of vents, this isn't the airiest helmet we tested.
Despite the number of vents, this isn't the airiest helmet we tested.
Credit: Zach Wick

Usability


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 comprise the bulk of this helmet'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 that does the job nicely.

giro radix mips - a mips liner, adjustable strap splitters, and an adjustable visor...
A Mips liner, adjustable strap splitters, and an adjustable visor make up the backbone of the features.
Credit: Zach Wick

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.

giro radix mips - this helmet's minimal weight was an excellent attribute for long...
This helmet's minimal weight was an excellent attribute for long pedals and grinding climbs.
Credit: Zach Wick

Should You Buy the Giro Radix Mips?


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 Giro Radix Mips is an excellent choice. In a world where each new mountain bike helmet release has a longer marketing brief than the last, the Radix Mips bucks the trend.

What Other Mountain Bike Helmets Should You Consider?


The budget-priced Lazer Coyote KinetiCore is an excellent alternative to the Radix, which offers top scores in impact testing. If you're looking for an alternative that prioritizes ventilation and pedal-intensive days, consider the Smith Engage MIPS.

giro radix mips - as always, we had a good time testing this helmet!
As always, we had a good time testing this helmet!
Credit: Zach Wick

Side-by-Side Comparison
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Zach Wick and Zach Lovell