Giro Manifest Spherical Review

Since their inception Giro has been at the leading edge of helmet technology, and the Manifest Spherical—with its dual-shell rotational impact protection—represents their latest innovation. While the designers at Giro have used the MIPS Spherical technology before in their ski and full-coverage mountain bike helmets like the Tyrant, the Manifest is their first crack at packing the tech into a lightweight half-shell trail helmet. After hours in the saddle wearing the Manifest we think they did a mighty fine job with it. We immediately found a lot to like, and we really had to dig to find complaints with this model.

Performance Comparison

Protection

The Manifest's MIPS Spherical rotational impact protection system is fairly unique among half-shell trail helmets. Like its beefier full-coverage sibling, the Giro Tyrant, the Manifest consists of two separate EPS foam liners connected by small elastomers that make up the MIPS Spherical system. The two shells are designed to rotate against each other in the event of an impact with the goal of reducing rotational forces on the head. The two shells have varying EPS foam densities to protect from both high and low-speed impacts. This system eliminates the need for the plastic interior liner found on most MIPS-equipped helmets, and according to Giro, is scientifically proven to reduce rotational motion from angled impacts. Giro believes that the Spherical system could provide additional protection from certain impacts based on data from internal as well as independent lab testing. Because we typically try to keep the rubber side down in testing, we can't comment on the system's effectiveness, but we think that the logic behind MIPS Spherical is sound.

In addition to the rotational impact protection, the Manifest Spherical offers above-average head coverage and a secure fit. The interior EPS shell drops down low on the rear of the head and around the temples, and the lack of a plastic liner between the internal padding and the EPS makes the fit feel deep and secure on your head. The exterior/upper EPS shell has what Giro calls an Aura arch running through intended to reinforce and improve the helmet's structural integrity.

Comfort

As soon as we tried on the Manifest we could tell that Giro put a lot of care into designing a comfortable helmet. Like most Giro helmets, the EPS liner contours nicely to a wide variety of head shapes without creating pressure points. Over the course of testing, we had a number of different riders try out this helmet, and nobody had any complaints about the shell shape. The shell's interior features padding that is fairly minimalist, but well placed enough to make it feel like you're putting on a well-cushioned ski or snowboard helmet rather than a lightweight mountain bike helmet.

Like any high-end mountain bike helmet worth its salt, the Manifest also offers a ton of adjustability to allow a wide variety of head shapes and sizes to find a secure, comfortable fit. The Roc Loc Trail harness has a huge range of adjustment with tiny indexed positions for micro-adjustment. Tightening it down pulls tension around the entire circumference of your head rather than just pinching at the back. The result is a snug fit that doesn't irritate over the course of a long ride. The harness can also be adjusted vertically across three different rear mounting points molded into the EPS shell. Simple, adjustable ear splitters keep the Manifest's straps flat against the side of your head, and the chin strap has a small rubber loop to keep excess strap from flapping around and distracting on the trail.

Ventilation

You know a helmet is well ventilated when even on a slow, hot, stifling climb you can feel air moving across the top of your head, and that's exactly what we experienced with the Manifest. Nineteen external vents that lead to internal channels in the EPS shell allow the wind to move through your hair and almost make it feel like you're not wearing a helmet at all at times. The ventilation was the first thing we noticed when we took this helmet out for a ride. It's one of the airiest helmets any of our testers have ever used— comparable to the 100% Altec that we tested.

When things inevitably got a little bit hot on long climbs we found that the Manifest's internal padding does a good job of absorbing sweat and keeping it away from your eyes. We didn't have any issues with sweat running down the lenses of eyewear or stinging our eyes. We would absolutely recommend this helmet for anyone riding in a hot climate or spending long hours in the saddle.

Features

Unlike some of the other Giro models that we tested that were a little light on features, the Manifest is loaded with little details to make your ride a little bit easier and more enjoyable. The exterior packs a fully-adjustable visor with a wide enough range of movement to allow goggles to sit on the front of the helmet while climbing. It's mounted to the outer EPS shell with hex-head bolts that can be tightened down if you want to lock the visor in one position. There are textured rubber pads at the rear of the helmet to hold a goggle strap in place along with similar grippers in the interior of the EPS air channels to hold sunglasses in place on the top of the helmet. We found the eyewear grippers especially useful to avoid fogging up sunglasses lenses while huffing and puffing our way up the mountain.

The Manifest's interior holds the already-discussed Roc Loc Trail harness, airflow channels, along with antimicrobial padding that discourages bacteria growth and keeps the helmet smelling fresh. The padding is held in place by small velcro patches and can be removed easily for cleaning. The list of features are rounded out with a Fidlock magnetic chin buckle. These buckles are getting more and more popular on modern high-end mountain bike helmets, and we're quickly growing to like them. It's super easy to buckle and unbuckle the helmet once you're used to the system, you can even do it one-handed, and the top side of the buckle contours nicely to the underside of the chin for a little bit of extra comfort.

Weight

The Manifest's weight was its only trait that doesn't stand out from the pack. It isn't the most lightweight mountain bike helmet available, but it certainly isn't a pig either. Giro's claimed weight for our size large test model is 370 grams, but when we threw it on the trusty kitchen scale it clocked in at 401 (just over fourteen ounces). This puts it on the lighter end of the spectrum of helmets we tested, but it doesn't match the lightest in the test that came in right around 350 grams.

Given the dual-shell design and ample weight-adding features, we're not surprised that the Manifest isn't among the lightest helmets in the test, but we're not particularly disappointed about it either. We think that a half-shell trail helmet like the Manifest should put protection, comfort, and convenience over weight, within reason of course.

Durability

If we're being honest, we aren't exactly kind to the products we test in the field. Our Manifest Spherical test helmet was subject to branch strikes on the trail, less-than-deliberate car packing, mud, rain, dust, and the at least one tumble on the garage floor, and it came out the other side fresh as a daisy. The tough outer shell is fused to the EPS using Giro's In-Mold technology, and the finish is resistant to scratches and scuffs.

Like all of Giro's high-end helmets, the Manifest is built to last. The visor is flexible enough to withstand minor impacts without cracking; the harness mounting points are securely molded into the EPS; the Fidlock buckle shouldn't wear out in the long run, and UV rays won't degrade the harness material over time. Our testing gave us no reason to believe that the Manifest will give up the ghost before it gives you plenty of use.

Value

The Manifest Spherical is a top-shelf helmet, and it comes at a top-shelf price. After countless hours on the trail, we think it's absolutely worth the money. If you're looking for the best helmet available, look no further than this model. For your money, you'll get a well-thought-out lid that you won't have to fuss over on those long days out on the trails. If you're looking to save some coin without sacrificing too much performance the Fox Speedframe Pro or Specialized Ambush 2 are great options.

Conclusion

We weren't sure what to expect from this dual-shell trail helmet, but the Manifest Spherical did not disappoint in our field test session. It came in at or near the top of almost all of our scoring metrics and edged out some fantastic helmets to becomes a tester favorite. Despite the high price, we would recommend this helmet to anyone looking for a daily driver for anything from lunchtime laps on the local trails to all-day backcountry epics.