Gear Review: Giro Manifest Mountain Bike Helmet

Explore our in-depth review of the Giro Manifest Mountain Bike Helmet. Discover its features, comfort, and performance. Is it your next buy?

Giro Manifest mountain bike helmet sitting on porch railing

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I think we can all agree that a good helmet is one of the most important gear purchases for mountain bikers. Right? Right. That’s why I always do my research when buying a new lid and I typically don’t balk at the sticker price. If an extra $100 is going to save my life, then it’s worth it.

Over the years, I’ve worn and tested many different mountain bike helmets from the Bell Super DH breakaway to the POC Kortal (which I really wanted to love, but it just didn’t fit right!) to my current favorite, the Giro Manifest with its spherical MIPS technology.

After testing this helmet out for 6+ months on a variety of different trails and terrain, in this post, I break down all the great features, why I love it, what could be better (spoiler: not much!), and how it compares to similar mountain bike helmet brands and models.

Ready to dive into this Giro Manifest Spherical review? Let’s roll!

Giro Manifest Helmet

  • Sizes: S, M, L
  • Weight: 12 ounces
  • Safety: MIPS Spherical
  • # of vents: 19
  • Replaceable liners? Yes
  • Adjustable visor? Yes
  • MSRP: $259.95
Giro manifest bike helmet


  • Excellent ventilation
  • Very comfortable
  • Back-of-head dial for a perfect fit
  • Lightweight
  • MIPS Spherical safety technology
  • Magnetic chin buckle


  • On the expensive side of helmets
  • Only comes in dark color choices
  • Not available in XL

First Impressions

When I first unboxed my Giro Manifest helmet, I was immediately impressed by its sleek, modern design. I got the matte olive color (green is my favorite!) but it also comes in several other hues, most of which are subdued and dark like black and gray. It would be nice if Giro added some brighter color options for riders who like a little pizzazz – maybe orange or electric blue?

Becky taking a selfie in the woods wearing Giro Manifest mountain bike helmet
I love the olive matte color!

The Manifest is surprisingly lightweight at only 12 oz. Giro has obviously put a lot of thought into striking a balance between protection and comfort. I’ve worn some helmets that are quite heavy and bulky and uncomfortable on long rides. Not this one! It’s light and has great ventilation, but still feels solid and safe.

The Manifest comes in three different sizes: small, medium, and large so you should be able to find a fit that’s just right for you. It’s a good idea to measure your head and use the size chart to make sure you get the right size. It would be nice if it was available in XL to accommodate larger head sizes.

The Manifest also feels high quality. The exterior shell is durable and strong while the interior padding feels plush and comfortable. The pads are also removable, so you can rinse them out after sweaty rides or replace them when they get worn out.

I also really like the chin strap and buckle with its magnetic clip, which makes it easy to clip and unclip with one hand.

Overall, my first impression of the Giro Manifest helmet is that it offers a great combination of comfort, style, and most importantly, safety. I was excited to put this helmet to the test and see if it lived up to my initial high expectations!

TWW Review Ratings

= Love it
= It’s ok
= Needs improvement

Design & Features

The Giro Manifest helmet is designed with a ton of great features. Here is what stands out to me the most:

MIPS Spherical Technology & Progressive Layering

One of the unique safety features of the Giro Manifest is the use of MIPS Spherical Technology as well as Progressive Layering, which, when combined, are designed to reduce rotational forces during an impact at both high and low speeds.

Basically, MIPS allows your head to move independently of the outer helmet shell, which helps deflect impact if the crash isn’t straight on. And let’s be honest, most crashes send riders tumbling.

“The unique ball-and-socket design of Spherical Technology utilizes two separate liners to help manage impact forces. The material and density of the inner and outer liners can be optimized with Progressive Layering to help manage a broad range of impact forces. When you combine the benefits of Progressive Layering with the market-leading MIPS® Brain Protection System, designed to help redirect rotational motion away from the brain, you get more comprehensive protection.”

Giro Website

Wind Tunnel Ventilation

The Giro Manifest is easily one of the most well-ventilated helmets I’ve tried. It has 19 vents and a Wind Tunnel Ventilation System that keeps air moving as you grind up long, sweaty climbs.

Part of what makes the Wind Tunnel Ventilation possible is the AURA reinforcing arch across the top. These small pieces of plastic add structure and integrity without bulkiness or weight.

Close up of large vents on Giro Manifest mountain bike helmet
The Girl Manifest has 19 large vents and an AURA Reinforcing Arch that helps keep air moving throughout the helmet

Fidlock Magnetic Buckle

One of my favorite features of the Giro Manifest is the Fidlock magnetic buckle. Once you’ve used this buckle, you’ll never want to go back to a traditional one!

Designed with a magnet that can be easily clipped and unclipped with one hand, it’s secure when fastened and useful when you’re holding that post-ride beverage.

Close up of Giro Manifest Fidlock chin strap buckle closed
Close up of Giro Manifest Fidlock chin strap buckle open

Eyewear grippers

Lastly, Giro has thoughtfully integrated eyewear grippers into the sides on the interior of the helmet, which allows you to securely dock your sunglasses when you don’t need them.

They’ve also added a strip of rubber on the back to make sure your goggle strap doesn’t slip when bombing down technical terrain.

Inside of Giro Manifest helmet showing rubber eyewear grippers
Interior rubber sunglass arm grippers
Back of Giro Manifest mountain bike helmet showing strip of rubber to prevent goggle strap from slipped
Rubber strip to prevent goggle strap from slipping

Comfort & Fit

The Giro Manifest is hands-down one of the most comfortable mountain bike helmets I’ve worn. Here are the main features that make the Manifest a no-brainer to wear:

Keep in mind that, as with all gear, fit and comfort is largely subjective. For me, the Giro Manifest is incredibly comfortable and fits me super well, but this might not be the case for everyone.

Ionic+ Padding

The interior padding is nice and cushy for a comfortable fit. The pads are also antimicrobial, which keeps the helmet feeling fresh even after long hours of hard riding

If it is time for a rinse, the three strips of padding can be easily removed since they are adhered via velcro. You can also replace the padding when it’s time with Giro’s Manifest Helmet Replacement Pad Kit.

Giro Helmet with padding removed and laid out next to it

Roc Loc Trail Air fit system

The Manifest helmet comes equipped with Giro’s proprietary Roc Loc Trail Air fit system. This is essentially a dial at the back of the helmet that allows you to adjust the fit with one hand. You can even adjust it while riding.

The reason I gave this section an orange rating is because the Giro Manifest doesn’t come in an XL, which some other helmet brands and models do. If you have a head circumference larger than 63 sm, you’ll need to look elsewhere.

back of Giro Manifest helmet showing the Roc Loc Trail Air Fit dial
The Roc Loc dial allows you to adjust the tension for a perfect fit

Adjustable visor

The adjustable visor on the Manifest allows you to change the visor’s position depending on whether you’re wearing glasses or goggles or need to shield your eyes from the sun.

Wind Tunnel Ventilation

As I mentioned above, the Manifest is designed with a Wind Tunnel Ventilation system that plays a significant role in its comfort. The 19 vents combined with deep internal channeling ensure optimum air circulation around your head, helping to keep you cool during rides.

Because of its great ventilation, the Manifest is a good choice for riders in warmer climates or those – like me – that sweat a lot.

Becky smiling for photo next to mountain bike at desert overlook wearing Giro Manifest helmet

Performance & Safety

Mountain bike helmets are (or should be!) designed with a singular goal: to keep riders safe.

Here’s how the Manifest is designed to keep your noggin intact:

Spherical Technology & Progressive Layering

For the Manifest helmet, Giro has combined MIPS Spherical Technology and Progressive Layering.

The unique ball-and-socket design of Spherical Technology helps manage rotational forces. Crashes don’t always happen straight-on; often, there are rotational forces involved. The MIPS technology is designed to handle these rotational forces by allowing two slip pane layers to rotate independently of one another.

Additionally, Progressive Layering used in the Manifest provides multi-density foam liners that are designed to handle a wide range of impact energies from low to high speeds.

Aura Reinforcing Arch

The AURA Reinforcing Arch at the crown strengthens the helmet’s integrity and structure. This reinforcement not only offers additional crash protection but also ensures that the helmet maintains its structure over prolonged use.

Fidlock Magnetic Buckle

The Fidlock magnetic buckle is another safety-oriented feature that makes sure the helmet stays secure on your head without being overly restrictive or difficult to release when necessary.

This is the second helmet I’ve owned that has this magnetic buckle (the other was the Bell Super DH) and I’m a convert.

CPSC Certification

It’s also worth noting that the Manifest meets all the safety standards set by CPSC (Consumer Product Safety Commission) in the US and for riders over 5 years of age.

Becky riding mountain bike down steep, chunky section of red rock trail in Sedona

Price & Value for Money

The Giro Manifest is definitely not the cheapest helmet on the market nor is it even middle-of-the-road. It’s a high-end, premium product designed for serious riders.

That being said, while it may be more expensive than many other options on the market, it’s worth considering what you’re getting for your investment. I personally think its safety features, high level of comfort, and impressive durability make it a worthwhile investment for serious mountain bikers.

You can’t put a price tag on safety!

Pros & cons

As a recap, here are the main pros and cons of the Giro Manifest:


  • Excellent ventilation
  • Very comfortable
  • Back-of-head dial for a perfect fit
  • Lightweight
  • MIPS Spherical safety technology
  • Magnetic chin buckle


  • On the expensive side of helmets
  • Only come in dark color choices
  • Not available in XL

How it compares

If you’re still shopping around, here is how the Giro Manifest compares against two other popular mountain bike helmets: the Giro Fixture MIPS and the POC Kortal Race MIPS.

Giro Fixture MIPS

Safety: MIPS

Weight: 11.5 oz

Vents: 16

Pros: Affordably priced with MIPS technology

Cons: Not super well ventilated

Price: $70

Giro Manifest

Safety: MIPS Spherical

Weight: 12 oz

Vents: 19

Price: $260


Safety: MIPS

Weight: 13.8 oz

Vents: 17

Pros: Great design & protection

Cons: Doesn’t fit some head shapes (like mine)

Price: $250

Final thoughts

Protecting your head and brain is, well, a no-brainer. Everything can change in a split second. One minute you’re having the ride of your life and the next you’re facedown in the dirt. Most times, you’ll stand up, brush yourself off, and continue on down the trail – maybe with a bit more focus.

But sometimes crashes are more serious and in those cases, it’s imperative that we are wearing a high-quality helmet to protect our precious little noggins.

For me, as someone who rides a lot, the Giro Manifest is my solution. It has a ton of great safety features yet it’s still comfortable, lightweight, and well-ventilated.

I know $260 is a lot for a helmet, but when it comes to my safety, I’m willing to pay the price.


Need to update your gear closet? Read through my gear reviews to make sure you get the perfect fit:

Have you tested out the Giro Manifest Helmet? What are your thoughts? What’s important for you when shopping around for a helmet? Let us know in the comments!

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