Giro Radix MIPS Adult Dirt Bike Helmet

Comfy but poor sweat management - the forehead pad has 4 drip points right over your glasses lens. If you don't sweat, this is a great helmet, if your do sweat, will drip on glasses all day long.

I have been riding with a fox helmet for the last 7 years, and I always bike through the winter without one because it is not large enough to fit over a beanie, and no one will make a large enough helmet, and I don't want to sweat inside a ski helmet, even though they really look cool. After looking for smith everywhere and never being able to find the XL version, I finally found this, and ordered the largest size. It fits great at about 23.5" with nothing but a bandanna, and the mips is a huge huge improvement in comfort, and was very easy to adjust. I did not think I would like the "y" connectors beneath the ears, but they actually work really well. Set the female buckle side first, pull the cord through to the other side, set the other side, and clip off the excess webbing, and singe the end with a lighter; good to go. The visor flips up just enough to fit a headlamp for night riding, and the helmet tilts back and fits large snow goggles. The only complaint I had, was...why don't helmet manufacturers put headlamp and goggle guides on every single helmet? Haven't we figured that out yet? So I spent a day looking at all the terrible 3m glue things that I know will melt and mush off my helmet and make it look like crap, and then I finally settled on using black midgrade size zipties, the 8" black ones. You can position them and route them under the mips so you don't feel them. If you are looking at the helmet from the rear, don't use the middle holes, but the holes to the left of the middle, and to the right of the middle. And that would be the holes on the upper and the lower, with the middle ones left open. So you put four ties, one in each corner, and position the part that zips down so the nub is sticking out. They make perfect little permanent non-glue goggle and headlamp catches, and it doesn't clutter up the helmet and make it look bad. I also added two on the front where the visor flips up, in the center hole, so you can shake your head like crazy as if you were riding over logs, and now your headlamp won't slide off the front of the helmet and slap you in the face. 6 zipties, and you are good to go. Awesome helmet, so comfortable and easy to adjust. Incorporate goggle straps and it is great!

I measured for my correct size per instructions and came out 59 or maybe a quarter of an inch less after using both a string and tape measure multiple times. My old Giro which is maybe ten years old and dropped on hard surfaces several times is a medium, but is tight and hard or impossible to fit a light cap, so I went with a large. In spite of multiple way to adjust and a week of riding and adjusting I could not get the front to sit high enough off my brow and was close to my eyebrows, even with the back ratchet as tight as it would go. My remedy was to buy a Sweat Buster and the extra thickness was just enough for a comfortable fit. My advice for those in between sizes is to make sure you can return or try on for fit.Otherwise I'm pleased. It's a heavier helmet and rides hot, but in exchange has really good protection coverage and feels secure.

I am a hardcore recreational trail style mountain biker who has had many helmets over 20+ years of riding. I have always liked the Giro fit system as their helmets fit my head great. Good looking, affordable, and comfy not to mention its MIPS! Visor is perfect length for a trail/enduro style rider. I don't know if I would recommend this as a cross country race helmet as the visor may get in the way of your view as your position on the bike is much more aero, but the visor can be moved. Note that if you buy the "hypnotic" color, the stickers have a gold to reddish mirror look kind of like look at a set of Oakley red/gold sun glasses. The picture makes on the web makes it look flat in color. I actually like it but was surprised at the color when I opened the box.

This was one of three helmets purchased for by husband, who has a 63.5 cm head, which in particular is wide at the temples/forehead. This XL Radix fits snugly but not uncomfortably for him. We also tried the Giro Register and Smith Signal size XL, both of which had overall adequate circumference but not the right shape. Hope this is helpful to those looking for a large, wider helmet. It was quite a journey finding this one!

I measured my head before to match the size chart and ordered the XL helmet but its way too large it moves around my head even with full adjust of straps

Helmet fits me very well. I followed the size guide. Unlike some other helmets I've owned, when I adjust the straps for fit, they stay adjusted. No strap creep. Nice ! Only quibble is the visor won't stay up...slides to the down position. Wish it had some positioning notches or something.For a MIPS helmet, it also seems very low profile, not oversized.

I was looking for a new helmet to use for both road and mountain biking after destroying my old giro helmet after being hit by a car. This helmet is the perfect solution for me. I like that it provides full head coverage while not feeling too bulky. I had tried the chronicle, but it was huge. It made me look like a bobble head. It also doesn’t just sit on the top of your head like some traditional road helmets do.

I already have a lot of difficulty finding caps and hats, having 62cm of circonference. But I also live in quite a cold place, with snow 5 months a year, but I enjoy them riding my fatbike in the woods. So with a hood or a toque, I needed something REALLY large and was ready to pay a bit more for quality and comfort. My XL model fits perfectly but it's a bit bulky (it's a trail hat), so you won't look very aerodynamic wearing this on the road. But it's made to take quite tough hits, so if you fall on tree trunks or boulders, you feel you're well protected all around your head. Great buy!

Live the helmet, fits my big head perfectly, great vents top of the line helmet. The Matte is easily scratched so be careful if you care about that.