GEAR REVIEW: Montbell Tachyon Pant

By Will Rietveld

The Tachyon Pant is a wind pant made of Montbell’s 7-denier Ballistic Airlight ripstop nylon coated with their Polkatex DWR and weighing 1.9 ounces. I have long wondered if these pants would suffice as rain pants in brief rain events and walking in wet vegetation, so I decided to give them a try. The weight savings compared to mainstream rain pants is significant.

The Montbell Tachyon Pant is a wind pant made of 7-denier nylon with DWR and weighs just 1.9 ounces. Will they suffice as rainwear in brief showers?

Prior to this test my rain pant of choice was the Montbell Versalite Pant, which weighed 4 ounces in the previous version (more on that later). The weight savings from the original Versalite Pant is not huge (2.1 ounces), but the thinner wind pant may also be more versatile. So, the question to be addressed here is: is the weight savings worth the potential drawbacks (getting soaked!) and are the lighter pants more versatile?

Specifications and Features

Manufacturer	Montbell  (www.montbellus.com)
Product	Tachyon Pant
Fabric	7-denier Ballistic Airlight ripstop nylon
Features	Elasticized waist with drawstring, key pocket
Weight	Manufacturer specification 1.9 ounces, measured weight 1.9 ounces
MSRP	$99

Description

The Tachyon Pant was created to pair with Montbell’s ultralight Tachyon Jacket (a wind shirt); both are made of 7-denier fabric and are the lightest to be found on the market. The Tachyon Pant is Spartan – no pockets or zippered leg openings. They do have an elastic band at the waist and a thin drawcord to adjust tightness. My wife removed the drawcord to reduce their weight to 1.75 ounces for size men’s Large.

The legs are slim, which is nice, and they do not have zippered openings at the bottom. However the opening is sufficient to get my size 12 trail runners through, which is also nice.

Field Testing

I tested the Tachyon Pant over two hiking seasons, using them as rainwear, windwear, campwear, and early morning trailwear on numerous desert and mountain trips. I live and hike in the Four Corners region of the Southwestern US, where precipitation is generally light and comes in the form of brief showers (with some wetter exceptions). For hiking and backpacking in the Southwest, we carry our rainwear a lot more than we wear it, so we generally go for the lightest rainwear that will do the job.

So, how water-resistant are they? That’s the key factor in this review; i.e., is the Tachyon Pant adequate rainwear in mountain showers or not?

The short answer is – not good enough. They were sufficient in very light showers and wet vegetation, but not for a longer (more than a half hour or so) rain event. While wearing some sand-colored hiking pants under the Tachyon Pant, and walking in the rain for about an hour, the outside of the pants wetted out (left), and my hiking pants were quite dampened inside (right). The dampened area consisted of my thigh area and down the inside of both legs, where the seams are.

So, bottomline, the Tachyon Pant is just not water-resistant enough to suffice as rainwear. They could work if a shower is very light and brief, if you can sit out a shower under a tree, or crouch under an umbrella. But those are big “ifs”. It’s probably better to opt for a really lightweight true rain pant.

The Tachyon Pant is versatile though; I can wear them as rainwear in brief light showers and wet vegetation, windwear, a shell layer over a light insulation layer in camp and sometimes in my sleeping bag, hiking pants on cool mornings, and warm up pants for sudden chills.

The Tachyon Pant is a great ultralight outer shell layer over insulation in camp.

I usually hike in shorts in the summertime, and find the Tachyon Pants get wet from the knees down when hiking in wet vegetation. Interestingly the Tachyon Pants stick to my skin when they get wet. I have not found that to be a problem because that makes the pants trimmer so I can more easily see my feet.

As mentioned in another review, I often use the Montbell Travel Umbrella (3 ounces) when I walk in the rain, hence limiting wet legs to the knees down. The Travel Umbrella could perhaps be “insurance” to avoid getting soaked in serious rain.

A downside of wearing shorts for summertime backpacking in the mountains is the evenings and mornings can be pretty chilly, for example 30F when I start out in the morning. I find the Tachyon Pants add a lot of warmth when worn over thin long johns in camp or over my skin for the first hour or so on the trail.

I hike off-trail a lot, and find herbaceous and woody vegetation have not damaged the Tachyon Pant, however they are no match for granite. With reasonable care, this pant will hold up for a long time. I have not hiked through stickery brush in the pants.

And finally they are great windwear, as they are designed for. When a cold wind comes up, they provide needed warmth, and they are very easy to put on/take off.

Assessment

Although the Tachyon Pant is not sufficiently water-resistant for use as rainwear,  I’m pleased with their versatility. It’s basically the lightest leg shell on the market, and keeps my legs warm on the trail and in camp. The pant will suffice as rainwear in a brief light shower, and walking through wet vegetation. But that’s not enough; more rain protection is needed, and I need to renew my search for some really lightweight rain pants.

As I write this review, I notice that Montbell has redesigned the Versalite Pant using Gore Windstopper fabric with water resistance, and the weight has shrunk to 3.2 ounces. That’s only 1.3 ounces more than the Tachyon Pant, and its real rainwear. Looks like I need to give the new version a try.