Giro Tyrant Spherical Review

Over the last few years, the mountain bike helmet market has become significantly more complex. What used to be mainly a two-style market—XC half-shells and DH full-faces—has bloomed into a complex landscape of beefed-up trail helmets, convertible half-shells, breathable enduro full faces, and everything in between. The Tyrant is Giro's latest offering in the full-coverage, open-face category, or as they call it "full cut." Helmets like the Tyrant are inspired by old-school open-face moto helmets and are designed as a versatile option to bridge the gap between full faces, trail helmets, and dirt jump lids. Before we started testing, we didn't have much experience with this style of helmet, so we were eager to get our hands on the Tyrant and see what it had to offer.

Performance Comparison

Protection

The Tyrant offers the best protection of any model we tested and represents the most gravity-friendly option in our test. This beefy full-cut lid has an EPS shell that extends far down the back of the head to provide top-notch occipital protection as well as a polycarbonate lower shell that is fused to the EPS and reaches down to cover the ears. The coverage alone is far better than most models in our test and reminded us a lot of our old little league batting helmets. The only other "full cut" model we tested was the Fox Dropframe, which offers similar coverage.

The Tyrant's protection doesn't stop at its coverage. Giro pulled out all the stops for this model and included an innovative dual shell protection system that they're calling MIPS Spherical. Unlike the standard MIPS system that is made up of a plastic liner that rotates inside of the EPS shell, MIPS Spherical comprises two separate foam shells that rotate against one another. Giro states that the two shells, "work like a ball and socket to redirect energy in a crash." The exterior layer is made of standard EPS to absorb high-speed impacts, and the interior is EPP, which is lower density and helps to absorb low-speed impacts for minor spills. While we didn't go out of our way to run into trees or get up close and personal with rocks to test the system, we think the dual-density-foam-on-foam slip plane makes a lot of sense.

While it offers excellent protection, we should be clear to note that the Tyrant is no replacement for a full face. Besides its distinct lack of a chin bar, the foam shell does not drop low around the head in the same way. The part of the shell that covers the ears is just padded polycarbonate and will not provide the same protection in a crash.

Comfort

Like most of Giro's helmets, the Tyrant is just about as comfortable as it gets. The interior shape of their helmets has been refined over the years to fit a wide range of head shapes, and it won't create pressure points or discomfort on long rides. The Tyrant's interior houses a sparsely-padded liner that is far more similar to those found on their trail helmets than the thick, heat-trapping padding of a full face. The only thick padding on the interior of the helmet surrounds the ears on the lower polycarbonate shell. We had a variety of testers try on this helmet and provide feedback, and we didn't get any negative comments.

The Tyrant uses a beefed-up version of Giro's standard trail helmet harness called Roc Loc Air DH that offers the same fit adjustment and comfort. The harness is adjustable both circumferentially using a dial at the back of the helmet, and vertically using a molded insert in the inner EPP foam with four snap-in positions for the harness. When the harness is tightened, it pulls tension evenly around the head rather than just pinching at the back like some other systems. This means that you can wear the helmet tight and secure without causing headaches over time.

Ventilation

We didn't have very high hopes for the Tyrant on hot days given its monolithic, all-encompassing construction, but we were pleasantly surprised at the ventilation quality once we got it out on the trails. In total, this model has 14 vents that lead to internal channels in the foam to allow air to cycle front-to-back as you move down the trail. It also uses Giro's Stack Vent technology, which comprises five vertical channels at the helmet's brow to allow hot air to move up and away from your glasses or goggle lenses. The idea behind this system is to avoid lens fogging, but we would be lying if we said we could tell if it made a difference compared to helmets without brow vents. Last but not least, the helmet has gaps in the padding around the ears that work as intake and exhaust vents and let air flow through the lower shell. This was our favorite aspect of the helmet's ventilation, and it went a long way in mitigating the full cut shell's heat.

While we were surprised at how well this model ventilates, we should be clear to note that it doesn't come close to matching the best ventilating helmets we tested. On the climb back to the top, this thing can get a little bit hot and stagnant just as we would expect from a full-coverage shell, but we do think that Giro did a good job keeping it cool given its intended purpose. When rating this model, we didn't grade it on a curve, and it shows. It provides similar ventilation to the other full-cut model we tested, the Fox Dropframe.

Features

Like we've said, it's clear that Giro pulled out all the stops when designing the Tyrant. It's packed with innovative features, most of which we've already covered because they're designed to improve its protection and ventilation. To recap, the Tyrant boasts the innovative MIPS Spherical dual-shell rotational impact protection, a Roc Loc Air DH harness system, stack vent technology to pull hot air away from eyewear, cheek pad ventilation, and interior channels to promote airflow.

In addition to the features we've already discussed, the Tyrant also wields an adjustable visor, goggle strap guide channels in the polycarbonate shell, and in-mold-fused EPS and polycarbonate shells for durability. The visor is easily adjustable without tools and provides plenty of room for stowing goggles on the helmet. The mounting points can be tightened either by hand or with an allen key if you want to ensure the visor stays put. The polycarbonate outer shell is fused to the EPS in the molding process to make sure that there's no chance of the two separating over time.

Weight

With so much coverage and all of the innovative features packed in, the Tyrant gives up considerable ground in the weight department. When we pulled out the kitchen scale, we were surprised to see that this behemoth came in at a whopping 718 grams (1 pound, 9 ounces). At a full 200 grams heavier than the closest helmet in the test it's clear that the Tyrant isn't going to help you win a hill climb any time soon, but we're willing to let the bulk slide a little bit for this model because of it's stated purpose. Giro designed this lid to keep you protected on the descents and the jumps, and they had no delusions of this being worn in any XC races.

Again, even though we're willing to overlook this helmet's weight a little bit, we didn't grade it on a curve and made sure to keep an accurate comparison with the rest of the field. For comparison, the other "full cut" open-face helmet we tested, the Fox Dropframe, tipped the scales at just 499 grams.

Durability

After four weeks of testing, our Tyrant still looks great. As we would expect from a top-of-the-line helmet, it has an overall quality construction, and we can't find any weak points that we would worry about in the long haul. The polycarbonate shell is sturdy and permanently fused to the EPS foam. The harness and strap mounting points are firmly ensconced in the shell, and the visor is flexible enough that we wouldn't worry about it breaking in a brush with the garage floor or a bad packing job.

We will mention that the black matte finish on our test helmet does seem to scuff and mark more easily than we would like. We had a few run-ins with brush and branches on the trail, and the shell shows some signs of battle. We're not overly concerned about it because it won't affect the helmet's longevity, but if you want your helmet to keep looking pristine for the long haul, we would suggest avoiding matte black.

Value

For a beefy helmet packed with innovative features, the Tyrant comes at a surprisingly reasonable price. It will cost you considerably less than the top performers in our test, so if you're looking for a little bit of extra protection and like the retro, open-face styling, we think this model is a great deal. If you like the additional protection but are worried about the weight, you might want to take a look at the Dropframe, which offers similar coverage in a lightweight package for the same price.

Conclusion