Montbell Tachyon Hooded Jacket Review

Bottom Line

From renowned ultralight gear company Montbell comes the whisper-light Tachyon windbreaker. With an impressive weight of 2.5 ounces, it ranks as one of the lightest jackets in our lineup. This extremely low weight, combined with its excellent breathability and packability, makes it one of our favorite windbreakers to take on your next backpacking trip or trail run.

Primarily used as a windbreaker on winter trail runs, the Tachyon quickly became our go-to layer for high-output outings. Aided by four finger-width vents in each armpit, the Tachyon is one of the most breathable jackets we tested. While others beaded perspiration on the interior with heavy sweat, the Montbell Tachyon let moisture quickly pass through the fabric to evaporate. This quickly became our favorite jacket to run in.

The Tachyon is extremely packable. With an internal stuff pocket, it packs down to about the size of a tangerine and stows easily in a running vest or coat pocket. However, this ultralight fabric is relatively fragile and not our top choice for hiking through brush or climbing when scrapes and abrasions are common. Perfect for thru-hikers, ultra runners, or anyone who counts every gram in their pack, the Tachyon is a super light option that offers great wind resistance.

How We Tested

Over two months, we wore the Montbell Tachyon on hikes and runs as well as backcountry and cross-country ski trips to field test its performance in multiple conditions. Our tests consisted of real-world exposure to the wind and elements. We also used a blow drier to test wind resistance and also completed a one-hour run while intentionally overdressed to test its breathability and moisture management.

Wind & Weather Resistance

Tested on trail runs above treeline on windy winter days – and with our blow drier – the Montbell Tachyon was impressively windproof. Its almost see-through material defied expectations and kept us completely protected from all wind. However, it is immediately evident that the Tachyon is not designed to resist any kind of water or precipitation. It wets through almost instantly. 

Although extremely quick to dry, the Tachyon is better suited for windy days without any chance of precipitation.

Breathability

The Tachyon Hooded Jacket quickly became our top choice for trail runs and sweaty uphill hikes due to its extremely breathable construction. We encountered no beading perspiration within the jacket – all moisture passed through and quickly evaporated. The Tachyon dries extremely quickly even when exposed to rain and snow. 

To further enhance the breathability, the Tachyon comes with four underarm vents slightly wider than a finger. This is an excellent feature found in no other windbreaker we tested. Ranking near the top of our lineup, we were impressed with the ventilation and breathability of the Tachyon. We will keep reaching for it on many more runs and hikes.

Weight & Packability

With a manufacturer-stated weight of 2.5 ounces and a measured weight of 2.7 ounces (men’s medium), the Montbell Tachyon is one of the lightest jackets in our lineup – one of only two jackets weighing less than three ounces. 

Thanks to its ultra-thin, seven-denier fabric, the Tachyon packs down roughly to the size of a tangerine. On the inside of the left side of the jacket, there is a small stuff pouch with a velcro closure. Impressively, the Tachyon also has two zippered hand pockets, which many heavier jackets do not have. The Tachyon is perfect for throwing in a running vest or backpack and forgetting about it until you need it. It’s even small enough to fit in the pockets of most hiking pants.

Comfort & Fit

The cut of the Tachyon can best be described as performance fit. It fits slimmer than other brands tested. The hem, in particular, is very trim and almost feels tapered. This makes it ideal for more slender bodies or for layering with only a base layer under it. However, the Tachyon can feel tight through the shoulders and arms, and the material lacks any noticeable stretch. 

The cuffs have an elastic opening but the hem does not. A more elastic hem may help eliminate some of the riding up and bunch we experienced when wearing this jacket with a running vest or hiking pack. This may not be the most mobile or elastic jacket for rock climbing or bouldering, but it is great for trail running or other activities where a trim profile is more comfortable.

Should You Buy the Montbell Tachyon?

The Montbell Tachyon is the perfect jacket for trail runners, thru-hikers, or anyone who counts every gram that goes in their pack. With only one jacket lighter, it’s one of our top choices for ultralight windbreakers. It’s impressively packable thanks to its velcro stow pocket that packs the jacket down to the size of a tangerine. We also like the four small vents in each armpit and perspiration-permeable fabric. Decidedly technical and slim-fitting, the Tachyon may lack the versatility to be used off-trail. However, it is perfect for shoving into a running vest, tight space in a pack, or even your pants pockets.

What Other Windbreaker Should You Consider?

Head to our gear guide to see the full lineup of best windbreakers.

Enlightened Equipment Copperfield Review: The only jacket in our lineup that’s lighter, the Copperfield is a minimalist wind jacket eschewing most features in favor of its extremely low weight.

Patagonia Airshed Pro Review: Fitting more like a shirt than a jacket, the Airshed Pro is extremely breathable and perfect for runs or aerobic outings.

Arc’teryx Squamish Review: If you’re looking for a jacket with more weather resistance but still being packable, the Squamish is an excellent choice.