Welcome! Ultralight backpacking is my passion, and keeping up on new technologies, gear, and techniques relevant to UL backpacking is what floats my boat. I'm always looking for the lightest, most functional gear to improve a lightweight or ultralight backpacking kit, and report my impressions and field testing results here. For hikers wanting to keep up on the latest and greatest ultralight backpacking gear, this is a good place to hang out. Also, there is a lot of information here (and on our informational website Southwest Ultralight Backpacking) on useful techniques and backcountry etiquette -- food for thought for hikers wanting to lighten their load and their impacts.

My goal for Ultralight Insights is to understand, test, and report on new technologies and gear of interest to lightweight and ultralight backpackers. It's a passion after all, so we just plain enjoy talking about it. I hope readers will add their own wisdom and comments, respond to my questions, ask their own questions, and correct me if I get something wrong. Happy hiking! Will

Friday, August 23, 2019

GEAR REVIEW: Therm-a-Rest Hyperion 20 Sleeping Bag

By Will Rietveld

In spring 2019, Therm-a-Rest, a division of Cascade Designs, introduced some seriously lightweight and technically advanced gear. The Hyperion 20 sleeping bag (and its companion Hyperion 32) is in that suite.

I tested the Hyperion 20 for summer backpacking. I previously used and recommended a 30F bag for summer backpacking, but as I get older I get colder and prefer a 20F rated bag. I also prefer a bag with enough shoulder girth to wear at least an ultralight insulated jacket inside to increase bag warmth when needed. So how did the Hyperion 20 meet those needs?

The Therm-a-Rest Hyperion 20 sleeping bag, new for spring 2019, features 900 fill-power Nikwax water-resistant down for warmth, a half-length zipper, and lightweight materials throughout to achieve a weight of just 20 ounces for size Regular.

Specifications and Features

Cascade Designs (www.cascadedesigns.com)
Therm-a-Rest Hyperion 20 Sleeping Bag
Temperature Rating
20F (EN tested to 32F Comfort, 20F Transition, -9F Risk Range
Sizes Available
Small, Regular, Long (size Regular Tested)
Bag Girth
Shoulder 57 in, hip 49.5 in, foot 43 in (size Regular)
Shell Fabric
10D nylon ripstop (shell and lining, DWR on shell)
13 oz of 900 fill-power down (size Regular)
20 oz, measured weight 20.5 ounces
Box baffled construction, zoned insulation, single pull half-length zipper with inside and outside pull loops and a tab and snap at the top, zipper baffle and hood rim baffle, 2 removable stretch pad straps on the bottomside, stuff sack and cloth storage bag included
Small $390, Regular $410, Long $430


When I first saw the Hyperion 20 at the summer 2018 Outdoor Retailer trade show, it featured TARs ThermaCapture technology, which is a thin heat-reflective film inside similar to that used in their NeoAir sleeping pads. However, it was later dropped due to “manufacturing and environmental reasons”. I was hoping to test that technology, it could have made a significant difference, but there were certain concerns about toxic fumes inside the bag. However, 13 ounces of 900 fill-power hydrophobic down is about right for a 20F rated sleeping bag without ThermaCapture.

The bag' s box baffled construction is basically thin mesh (think mosquito netting) baffles shaping and separating the down chambers. And the zoned insulation means that 70% of the down is on the top and sides and 30% is on the bottom. Down on the bottomside gets compressed, and presumably a sleeping pad provides supplemental insulation.

I note that the temperature rating implied for this bag is 20F, which suggests it’s comfortable at 20F. That’s not quite true; the EN test says that its comfortable at 32F, the end of comfort arrives at 20F, and at -9F your life is in danger.

Sleeping bag warmth ratings and sleeper warmth is complex, and a disclaimer is often provided. The equation consists of factors like the amount and fill-power of the down, bag girth (a slimmer bag is warmer), and bag construction. A bag’s warmth rating is just one factor to evaluate it; other useful factors are the bag’s fill weight (13 ounces for Size Regular), double layer loft (4.5 inches in this case), and shoulder girth (the specification for the Hyperion in size Regular is 57 inches, but we measured it at 58.5 inches). And, of course, people vary in how well they stay warm.

For me, the red flag on this bag is its specified 57-inch shoulder girth. That data was not available when I received the bag, but I assumed it was similar to other TAR bags, like the Parsec 20 which is 62 inches. Ultralight backpackers like me will love the bag’s 20 ounce weight, but the tight shoulder girth may limit wearing any insulating clothing inside (see field testing section).

The Hyperion’s 10-denier shell and lining fabric is a good weight saver; it’s hard to go much lighter than that. Also its half-length single-pull zipper (it looks like a #3) saves a little weight. Single-pull means it’s sewn in at the bottom, has only one slider, and won’t separate.

Overall, TAR has done a diligent job of trimming weight and maximizing warmth of the Hyperion 20.

Field Testing

I tested the Therm-a-Rest Hyperion 20 on seven trips: one spring car camping trip in the Southern Utah backcountry and six backpacking trips in the Southern Colorado Rockies. The lowest temperature encountered was 34F. I slept under the stars, in 3-person double-wall tent, in a 1-person floorless Dyneema shelter (shown), and in a 1-person silnylon single-wall tent.

In spite of the bag’s slender shoulder girth, I initially tried sleeping in the bag wearing a full complement of UL camp clothing (thin baselayer + ultralight synthetic insulated jacket + ultralight down jacket.) The jackets were not as bulky as they might sound, weighing 6 ounces and 5.9 ounces, respectively. With those clothing items worn, I found it very difficult to completely zip up the bag, and it was necessary to snap the tab at the top of the zipper to keep it from opening on its own. I’m 6 feet tall and the bag (rated to 6 feet) just barely fit my length.

Next I tested the bag wearing only a thin baselayer and the ultralight down jacket described above, and that made a remarkable difference – the bag felt much roomier inside and the zipper was fairly easy to fully close and secure with the tap and snap. I wore that clothing combination (thin merino baselayer plus Montbell Plasma 1000 down jacket) inside the bag on my next five backpacking trips.

Note that the zipper curves at the top to the base of the hood. When the bag is tighter, as with wearing too much clothing inside, the zipper is hard to operate and snags more because of the tension on the zipper. I got along with the small zipper and its two cordloop pulls a lot better when I wore minimal insulated clothing inside.

As far as bag warmth, I stayed warm in the Hyperion 20 down to 34F one night, and numerous nights in the 40sF, but I was not able to test the bag’s 20F lower limit during my testing. The bag’s fill weight of 13 ounces of 900 fill-power down is about right for a 20F bag rating, so the Hyperion 20 is on target with comparable bags. A simple method to compare bags with different down fill-power is to multiply the fill weight by the fill-power to get the total down volume in cubic inches.

I found the bag’s removable pad straps on its bottomside handy for helping to hold a sleeping pad in place, especially a slippery one like the Therm-a-RestNeoAir Uberlite I co-tested with the Hyperion. If they are not needed they are easily removed to save a smidgeon of weight. Note that using the pad straps conflicts with side sleeping.

The bag’s hood adjustment is a one cord design with an external cord loop and anchored cordlock. Pull on one side of the loop to snug one side of the hood; pull on the other side of the cord loop to snug the other side of the hood.


Overall I found the Therm-a-Rest Hyperion 20 quite liveable and warm, despite its slender shoulder girth. Fortunately the measured shoulder girth (58.5 inches) was a little roomier than the specified shoulder girth (57 inches), and that relatively small amount made a big difference. The Hyperion works for me if I limit clothing inside to a thin baselayer plus a thin ultralight jacket. That allows me to get the zipper closed without much snagging and the top tab snapped to keep it zipped. Legwear is a lesser issue regarding room inside the bag. This basically makes the Hyperion 20 a summer bag for mountain backpacking; it likely will be chilly in the shoulder seasons.

Readers might be wondering what the circumference of my upper body is so they can evaluate their fit in this bag; I’m 44 inches around my upper arms wearing a thin baselayer, and 47.5 inches wearing the baselayer plus a thin down jacket. My advice is to measure your shoulder circumference wearing similar clothing before you consider the Hyperion. If you are at or below my dimensions, you are good; if you are larger or prefer to wear more clothing inside your sleeping bag, look for a roomier bag. Or consider getting the Hyperion size Long to get an extra inch of shoulder girth.

The MSRP of $410 for the Hyperion 20 Regular length is a good value for a 900 fill-power down insulated ultralight sleeping bag. And its 20-ounce weight is hard to beat – 13 ounces of down and 7 ounces of other materials – it’s the same weight as many ultralight 30F down sleeping bags.

Overall, Therm-a-Rest is solidly into the ultralight down sleeping bag market with the Hyperion 20 being a good choice at 20 ounces for a 20F down bag. Interestingly, Therm-a-Rest has a Better Sleep Guarantee, which they describe as “All Therm-a-Rest sleeping bags and quilts are covered by our Better Sleep Guarantee. When you wake up on a Therm-a-Rest sleeping bag or quilt, we're confident you'll wake up feeling better than ever. If you are not completely satisfied, return it within three months with the original receipt of purchase and we will give you a full refund- no questions asked.” They stand behind their bags!

GEAR REVIEW: Therm-A-Rest NeoAir Uberlite Air Mattress

By Will Rietveld

I was talking with a friend the other day and we reminisced to 20 years ago when there was very little ultralight backpacking gear available for purchase and many of us made our own. A “lightweight” sleeping pad at that time (often labeled “ultralight”) weighed a pound. Fast forward to the present and we now have the Therm-a-Rest Uberlite pad that weighs just 6 ounces in Size Short, 8.8 ounces in size Regular, and the luxurious Large at 12 ounces. All are thick and comfy, and have a sufficient R-2 rating for summer use.

What’s not to like? Well, it’s mostly all positives, but there is one significant problem that I point out in this review, along with a solution. Read on, or skip to the bottom.

The new Therm-a-Rest Uberlite Pad comes in sizes Short (shown), Regular, and Large. It’s currently the lightest inflatable sleeping pad on the market.

Specifications and Features

Cascade Designs (www.cascadedesigns.com)
Therm-a-Rest Uberlite Sleeping Pad
Small, Regular, Large
Small is 20 in wide x 47 in long x 2.5 in thick; Regular is 20 x 72 x 2.5, Large is 25 x 77 x 2.5
Small is 6 oz (5.4 on my scale), Regular is 8.8 oz (8.9 on my scale), and Large is 12 oz (not tested)
Top is 15D ripstop nylon, bottom is 15D nylon
Small $140, Regular $180, Large $210


By eliminating the heat-reflecting coating on the internal baffles and adopting lighter fabrics, Therm-a-Rest (TAR) has squeezed some weight out of their NeoAir pad line, making them now truly ultralight. For a size Regular pad, the weight drops 3.2 ounces compared to their XLite pad (see comparative specs in the table below). While some features are also diminished (which I will get to in a minute), comfort is not one of them. This approach works for me, mainly because I value light weight over features.

Uberlite (Regular)
XLite (Regular)
15 denier
30 denier
8.8 ounces
12 ounces

The triangular baffle construction inside the pad is the same as previous NeoAir pads, but the heat-reflective ThermaCapture coating is eliminated, resulting in a pad that is equal in physical comfort, but losing some insulation (R-value is 2.0 compared to 3.2 for the XLite), and happily the annoying nosiness of previous versions of the NeoAir. The lighter fabric means less durability (the Uberlite is 15 denier and XLite is 30 denier). The lower R-value of the Uberlite means it is intended for summertime use. I might add that the XLite pads are still available, and some hikers may prefer them because they are warmer and more durable.

Field Testing

Testing the Therm-a-Rest Uberlite sleeping pad in the Southern Colorado Rockies. Size Regular shown. 

I received the size Regular Uberlite pad in January, and size Short in May, so I couldn’t get in any mountain testing until June. My testing consisted of one spring car camping trip in the Southern Utah Canyonlands country in a 3-person tent, 6 backpacking trips in the Southern Colorado Rockies sleeping on a plastic groundsheet in a floorless Dyneema shelter, and one volunteer trip in Utah’s La Sal mountains sleeping several nights in a 1-person silnylon tent with silicone stripes painted on the floor. Following are my testing results by attribute:

Ease of Inflation – The Uberlite inflates quickly by mouth; about 12 lungfulls for the size Regular pad. The pad has an antimicrobial treatment on the interior to prevent mold forming inside.

Sizing – I found the Short and Regular pads’ width of 20 inches to be adequately wide. That’s the “standard” width for a size Regular pad. I’m a side sleeper, and find I need to adjust my hip position when I turn over, but that’s not a problem. For those who require or prefer more width or length, a size Large pad is available with 25 inches of width and an extra 5 inches of length.

Comfort – Excellent, as expected. It’s hard not to be comfortable on a 2.5-inch inflated pad. I found the pad most comfortable when it’s inflated a little less than full. Three sizes are available to meet body size and preferences. The size Short still has the “dropoff” issue at the foot end, but that is remedied by putting something under your feet or curling up.

Warmth – As mentioned, the R-value has gone down to 2.0, which is minimal. I found it to be warm in my testing, where temps typically dropped into the low 40s F and one night at 34F, but it could be chilly below that, which I did not test. It may not be warm enough for some people, but I have a remedy for that later in this review.

Noisiness – Gone.

Durability – On my first backpacking trip with the Uberlite pad I camped in a grove of spruce trees on smooth ground covered with spruce needles. I slept in a floorless  Dyneema shelter and used a thin plastic Gossamer Gear Polycro groundsheet under the pad. You guessed it; the pad was punctured by a spruce needle on my first backpacking trip with it. The patching kit that comes with the pad is convenient and works perfectly: clean the spot with a provided alcohol swab and let it dry, compress a glue dot around the hole, and cover that with a Type A patch.

Patched puncture from a spruce needle. The smashed glue dot (circle) probably wasn't necessary for a small puncture, but I used it anyway to try it out. The dot in the center is my mark of the hole's location, not the hole itself.

Pricing – The Uberlite is pricey: $140, $180, and $210 for sizes Small, Regular, and Large, respectively. Each size costs $10 more than the XLite, so we are reminded that ultralight gear costs more for less weight. Ah well, you put your money (if you have it) where your passion is!

Slip-Resistance – I saved this attribute for last because it is where the problem lies that I alluded to earlier. The Uberlite basically doesn’t have any slip-resistance. The first time I tested the size Regular pad was a car camping trip in the Southern Utah backcountry, sleeping in a 3-person double-wall tent on a slight incline. The pad was like sleeping on a water slide; I chased it all over the floor of the tent trying to stay on top of it! I had the same experience sleeping on a thin plastic groundsheet while backpacking, and finally resorted to sleeping with the pad directly on the ground (no damage done, but not recommended).

The first solution I tried was the silnylon tent with silicone stripes painted on the floor, which is standard procedure for overcoming the slipperiness of silnylon. It didn’t work; I still slid around the tent floor. I also tried painting stripes of diluted silicone on my plastic ground sheet, and the pad itself; no success. The silicone easily rubbed off the slick nylon surface of the pad.

I tried painted diluted silicone on the bottomside of the pad to provide some slip resistance. It readily rubbed off and did not keep the pad from sliding around.

On a trip where I slept in a 1-person silnylon tent, I took along a piece of “non-skid rug pad” (used to keep rugs from creeping) to try another solution. It worked, but the rubbery rug pad is too heavy for backpacking, especially if you take a full pad length of it.

Next I tried a Gossamer Gear Thinlight pad, which is a full-length one-eighth inch thick closed-cell Evazote foam pad weighing just 2.5 ounces. That worked perfectly; the Uberlite didn’t budge on the bottomside.

But that solves only half the problem; a smooth nylon-shelled sleeping bag also slides on top of the Uberlite. Note that some sleeping bags’ shell fabric is more slip-resistant, and quilt users are less likely to have a problem with top sliding. And one could also use a Thinlight pad on both sides of the Uberlite.

I came up with this approach to provide slip-resistance to BOTH sides of the Uberlite pad using one Gossamer Gear Thinlight pad. Simply wrap the Thinlight pad around the Uberlite pad so the ends of the Thinlight are on the bottomside, and use pad straps on a sleeping bag (the Therm-a-Rest Hyperion 20 in this case, which I co-reviewed with the pad) to hold the Thinlight pad in place. This places the Thinlight under my hip, where maximum compression holds it and the sleeping pad in place. However, the Thinlight pad only provides extra puncture protection in that location. I found the wrapped Thinlight pad stays in place very well without the pad straps; the important point is to have the overlapping ends of the pad on the bottomside.

I like the Gossamer Gear Thinlight pad solution best, because the Thinlight is a multi-purpose piece of gear: it adds insulation to the Uberlight pad, protects it from punctures, can be used as backpanel padding in a pack with a pad sleeve, and serves as a sit or nap pad or camp seat.


The Therm-a-Rest Uberlite pad is a welcome addition to my ultralight gear kit, allowing me to cut a few more ounces. Granted, the Gossamer Gear Thinlight pad I take when using the Uberlight pad can offset the weight savings, but when I use a pack with a pad sleeve I can insert the Thinlight instead of other padding. I also like the extra utility of the Thinlight, as mentioned above.

Eventually, perhaps, Cascade Designs will fix the slipperiness issue of the Uberlite pad, and a user corrective measure won’t be needed. Other than the lack of slip-resistance, I am impressed with the quality, light weight, and comfort of the Uberlite pad.

It’s interesting to note that other reviewers focused more on the Uberlite’s elimination of the annoying “crinkly” sound characteristic of earlier versions of the NeoAir pad. The noisiness of the NeoAir really bothered a lot of people. I didn’t find it to be a problem, but I’m half deaf, so that’s one advantage of hearing loss. They hardly mentioned the slipperiness issue, but I consider it to be a significant problem that can confound one’s happiness in the wilderness.

Another issue with the Uberlite that deserves some cautionary commentary is its reduced durability. Yes, nylon is highly resistant to abrasion, but it is susceptible to puncturing or cutting. Thus the Uberlite, as with most ultralight gear, requires careful use. If you are hard on gear, the more durable TAR XLite pad might be a better choice. I like the combination of the Uberlite plus a Gossamer Gear Thinlight pad because the Thinlight provides slip-resistance, puncture-resistance, and extra insulation.

Bottom line, I give the Therm-a-Rest NeoAir Uberlite sleeping pad a thumbs up, with the caveat that you will likely have to remedy its lack of slip-resistance. If you come up with another good solution post it below.

Saturday, July 13, 2019

GEAR REVIEW: Topo Athletic Ultraventure Trail Shoe

By Will Rietveld

Topo Athletic is a relatively new shoe company that makes several trail models of interest to lightweight backpackers and trail runners. Features that appeal are light weight, synthetic materials, stitchless (welded) construction), a wide toebox, and snug heelcup. I have previously tested two Topo models – the Terraventure and Hydoventure – and loved both of them.

A new model in Topo lineup is the Ultraventure. This review will focus on how it’s a bit different from the two models I have previously tested, and how it compares with the popular Altra Lone Peak shoe, now in version 4. (Topo Athletic photo.)

Specifications and Features

Topo Athletic (www.topoathletic.com)
All synthetic: nylon mesh upper, EVA midsole, rubber outsole
Stack Height
30mm heel/25mm forefoot, 5mm heel to toe drop
Size men’s 12 tested: 11.9 oz/shoe; mfr specification 10.4 oz/shoe for men’s size 9; 8 oz/shoe for women’s size 7
Durable breathable mesh upper with TPU overlay pattern, 3-piece multi-density midsole, drainage gills for water release, Vibram XS Trek outsole, built-in attachments for Topo gaiter.


Most Topo shoe models have no or low heel to toe drop. The Terraventure and Hydroventure shoes I previously reviewed have 3 millimeters of drop; the Ultraventure has 5 a millimeter drop. Also, compared to those shoes, the Ultraventure has significantly more cushioning and support.

The upper is a soft nylon mesh with generous TPU overlays optimized for breathability and durability.

The outsole is Vibram XS Trek rubber with an aggressive lug pattern for traction and ample spacing between the lugs to shed mud and snow. (Topo Athletic photo.)

The Ultraventure has “gills” on both sides of the toebox to speed drainage and drying time.

Field Testing

I tested the Ultraventure in fall, winter, and spring in a wide range of conditions while day hiking, trail running, and backpacking; 33 trips in all. Because of the timing, my testing was mostly on trails, but I got in a good bit of off-trail use as well.

The first thing I noticed (and liked) about the Ultraventure is its extra cushioning. On long day hikes and backpacking days, I was able to hike 10 hours in them without foot fatigue, and I never had a blister.

A second feature I really like is their welded construction, meaning no stitched seams to come apart. And there is a very durable TPU rand around the toebox, a very vulnerable area for abrasion from off-trail bushwhacking.

Thirdly, I really like their wide toebox. That’s expecially important for me because I have wide feet (E width), but most thru-hikers and fastpackers like that feature because their feet swell during a long day on the trail.

Their stability on trails is excellent. However, when hiking off-trail (which is not necessarily this shoe’s intended purpose) I needed to tighten the laces tight over my instep to avoid rollover, especially crossing steep sidehills.

The breathability of the upper is very good. When a manufacturer chooses a fabric for the upper of a shoe, breathability needs to be balanced with keeping sand and dust out. I have tested shoes with a coarse mesh upper that were extremely breathable, but they allowed lots of trail dust and sand (when hiking in the desert) to go through, which is an obvious disadvantage. Topo has chosen well on the Ultraventrue.

Since the shoe is made with a breathable mesh, they are not water-resistant at all. They get wet inside easily, and I found they do not dry out quickly. I did not notice any benefit from the “gills” on both sides of the toebox. The gills function well to pump free water out of the shoes, but don’t seem to make much difference in removing absorbed water.

The Ultraventure has an aggressive traction outsole, which performs exceptionally well in dry and muddy conditions, but it tended to slip sideways on inclined snowbanks.

As you can see in the photo the Ultraventure came out of my testing with a lot of life left in it, which is a good testament to its durability.

However, I am not a fan of the Topo gaiter. It attaches with a typical lace hook at the front and two inverted “C” hooks at the heel. I found the lace hook comes loose sometimes, debris enters from the sides (which barely cover the shoe’s ankle cutout), and the rear hooks occasionally come loose. All of these issues occurred when I used the shoes for bushwhacking off-trail, which is not their intended use. The heel hooks are difficult to attach with the shoes on, so I typically leave the gaiters attached to the shoes and enter the shoe through the attached gaiter, which is a bit cumbersome but easily mastered. I prefer a tighter fit and a hook and loop attachment low on the heel.


I can say with confidence that the Ultraventure is my favorite Topo trail shoe so far. I really love the wide toebox, extra cushioning, extra support, traction, and durable materials and construction.

For runners and hikers who prefer a shoe with a wide toebox, the main choices are Topo Athletic and Altra shoes. Altra shoes are always zero drop, and Topo trail shoes have some heel rise (3mm or 5 mm). I have tested both brands in several models or versions and find that zero drop or low drop (for me) does not make any consequential difference. My feet readily adapt to the small differences in drop, and I don’t notice any difference in performance; both brands perform well for my purpose.

I like the lighter weight of the Topo shoes compared to the Altra Lone Peak, which is a beefier shoe, and I also like the Topo welded construction compared to the Altra stitched construction.

Toebox width of the Topo Ultraventure (left) compared to the Altra Lone Peak 4 (right). I overlaid the toebox of the Ultraventure with the Altra Lone Peak 4 and found the outside width to be nearly identical (the Topo shoe was about 2 millimeters wider), so no significant difference. Note that the inside width is not easily measured.

I am not impressed with the “mesh” upper of the Altra Lone Peak 4; it’s a bit stiff and doesn’t seem to be very breathable. I like the upper on version 3.5 more. I much prefer the upper on the Ultraventure, meaning the combination of soft breathable mesh, TPU overlays in the right places, and welded construction.

However, I will take the Altra Trail Gaiter any day compared to the Topo Gaiter. It stays attached and keeps debris out. I have not tried the Altra Four-Point Gaiter.

Which shoe do I like better? Well, it’s like loving your children; you love each one for different reasons, and they’re both exceptional. Both deserve a close look by trail runners and lightweight backpackers.

Saturday, May 11, 2019

GEAR REVIEW: Montbell Tachyon Parka (Windshirt)

By Will Rietveld

Just to be clear, although this jacket is called a “Parka”, it is in fact a hooded, featured windshirt. At 2.5 ounces, it’s likely the lightest one to be found. Montbell’s Ex Light Wind Jacket, made of the same fabric but Spartan for features, weighs 1.7 ounces. So, are the Parka's features worth the extra 0.8 ounce?

The Montbell Tachyon Parka features a full-height front zipper, an attached adjustable hood, two zippered hand pockets, and an internal key pocket. It’s made of a more breathable version of their 7-denier Ballistic Airlight nylon fabric.

Specifications and Features

Montbell (www.montbell.us.com/)
Tachyon Parka
7-denier Ballistic Airlight ripstop nylon with Polkatex DWR
Attached adjustable hood, 2 zippered hand pockets, full-height front zipper, interior key pocket, elastic cuffs
Size Large tested, 2.7 oz; manufacturer specified weight (size Medium) 2.5 oz


Montbell is known for providing a range of versions within each of its product categories, so it is not surprising to find 13 different windshirts on their website, including a wind vest! The Tachyon series is the lightest, featuring 7-denier fabric that is remarkably water-resistant and durable.

According to the Montbell website, the “Tachyon Parka has been redesigned to significantly increase breathability without sacrificing its wind blocking performance. With the new fabric, we have manipulated the weave and how we process the material to expertly balance its ability to release built up humidity inside the jacket, yet still block wind.” Improvements are always welcome, but how much difference does it make?

The Tachyon Parka has the “essential” features most hikers would want – a full-height zipper, attached adjustable hood, and zippered hand pockets. It’s actually pretty amazing that Montbell is able to produce a windshirt with these features that weighs just 2.5 ounces (size men’s Medium).

Field Testing and Performance

I tested the Tachyon Parka on 23 outings while day hiking, backpacking, snow walking, snowshoeing, and mountain biking. I normally wear a size Large, and the sizing is spot on. I'm wearing it layered over an ultralight down jacket, camped at 11,800 feet on a chilly late September morning.

 I have previously tested the 1.6 ounce Montbell Tachyon Jacket (now the Ex Light Wind Jacket), which is Spartan, save for a full-height front zipper. I really like it for its simplicity and light weight, and it’s a no-brainer to take a windshirt in addition to a rain jacket for windwear because it performs better for that purpose.

Now I have to evaluate carrying the Tachyon Parka instead, and adding 0.8 ounce to my gear kit. It’s weight creep; so is it worth it?

The hood adds a little extra warmth on a cold morning, and its nice to have when the wind is howling in my ears. I often wear a billed cap over the hood while hiking to keep the hood from inflating in the wind.

I also sleep in a hoodless sleeping bag these days, and having a hood on a windshirt or down jacket is a good way to keep my head warm as needed.

And the zippered pockets are handy for carrying, and securing, smaller items on the trail and in camp.

Montbell claims that this new Tachyon windshirt has increased breathability because of changes in the manufacturing of their 7-denier fabric. So, is there a noticeable difference? I would say yes, there is, but it’s not dramatic. In cold conditions I can hike for extended periods without steaming up. In cool shady conditions I can hike longer before getting too hot. However, in the Southwestern US where I live, the sun is the wildcard. Even on cooler days, if the sun is shining, it doesn’t take long to overheat while hiking while wearing a windshirt. As usual, hiking while wearing a windshirt is most comfortable when it’s cloudy, cool, and breezy/windy.

When you think about it, a breathable windshirt may be an oxymoron, or at least a fine line to achieve. Like a waterproof-breathable rain jacket -- which needs to be waterproof first, then breathable – a windshirt needs to be windproof, then breathable. In each case the latter factor is a measured amount that does not compromise the former factor. And so the bottom line is a W-B rain jacket is not very breathable, and a breathable windshirt is not very breathable either. But the relatively small amount of breathability helps, and is better than a solid barrier.


It gets down to whether you have a use for the features or not. The extra weight is miniscule to a lightweight backpacker, but it matters to an ultralight backpacker trying to keep her base weight down to 5 pounds or so.

Since I started using a hoodless sleeping bag, a hooded windshirt and a hooded down jacket have more utility to keep my head warm, so I’m more likely to carry a hooded windshirt.

It’s nice to have options.

Friday, May 10, 2019

GEAR REVIEW: Altra Lone Peak 4 Mid RSM and Low Trail Shoes

By Will Rietveld

The new Altra Lone Peak 4 takes another step in the evolution of this popular trail shoe. It’s popular because its shape/fit, materials, support, cushioning, traction, and light weight are on target with what hikers and trail runners want.

What’s new with this new edition, and how is it better? And further, are there advantages (or not) of switching to the mid-height waterproof/breathable version versus a traditional low-cut shoe?

I started out testing the new Altra 4 RSM Mid (left), but after discovering a few quirks I decided to compare it with the Altra 4 Low (right). This review is the outcome of one hiker’s experience with both versions.

Specifications and Features

Altra Running (www.altrarunning.com/)
Lone Peak 4 Mid RSM and Low
All synthetic. The Mid RSM has an eVent waterproof-breathable membrane; both shoes have a nylon fabric upper with TPU overlays, EVA midsole, and rubber outsole.
Stack height 25mm, zero drop
Notable changes are: eVent membrane in the waterproof-breathable version, new nylon fabric upper; an added webbing loop on the instep that enables better cinching ability; a new full-length rock plate that resembles the skeletal structure of the foot; and an improved traction outsole.
Size 12 tested. Average weight of the Mid RSM is 15.2 oz; average weight of the Low is 12.3 oz.
Mid RSM is $160; Low is $120


RSM stands for Rain, Snow, and Mud. The big change in the Mid is a switch from NeoShell to eVent for the waterproof-breathable membrane. I have always preferred eVent because of its better breathability. Both the Mid and the Low are available with a mesh upper that is not waterproof, and the RSM waterproof-breathable version.

This is my first time testing the mid-height version of the Lone Peak, so I have no experience with the previous NeoShell version to compare it to. However, I have tested the Lone Peak 3.0 and 3.5 Low.

The most noticeable change from the Lone Peak 3.5 is the new upper fabric, which looks like ripstop nylon compared to the woven fabric look of its predecessor. Both have a soft feel. The 3.5 had a dense overstitching pattern on the toebox to reinforce it, while the 4.0 has TPU overlays.

The other main upgrades – a static loop on the instep to enable better clinching, enlarged and articulated rock plate, and improved traction outsole – are less noticeable but significant and functional.

Overall, the improvements justify kicking up the Lone Peak up a notch from 3.5 to 4.0.

Field Testing and Performance

I tested the Lone Peak 4.0 on a total of 33 outings, which included trail hiking, off-trail hiking, trail running, snow and slush hiking, backpacking, scrambling, and mountain biking.

Unfortunately, on only my second time out in the Lone Peak 4 Mid RSM I caught the toebox of one shoe on a tree stub and tore a hole in the upper mesh. I tried repairing it with a Type A patch and McNett Tenaceous Tape, but neither product worked. So that shoe leaked through most of my testing.

In my testing of the Mid RSM in slush and water, I ended up with damp socks on both feet; the left one more so because of the patched tear. Upon further inspection I noticed that the right shoe also had some small abrasion holes in the fabric on the sides of the toebox. This would indicate that the new fabric is not all that durable, at least for off-trail backpacking.

 Weight-wise, in my shoe size, the Lone Peak 4 Low is only a smidgeon heavier than the version 3.5 (12.3 oz/shoe versus 12.2 oz/shoe). The MSRP has remained the same ($120).

My rationale for testing the Lone Peak Mid 4 RSM was my perception that it would provide better ankle support and be more stable and protective for off-trail backpacking. Also, the waterproof-breathable version would be a good choice for hiking in early- and late-season snow, as well as summer rains.

However, overall, the Mid 4 RSM did not meet my expectations.

Before I get into the details, allow me to mention that your experience may be different; choosing a shoe brand and model is a very personal thing, like choosing what type and brand of underwear you wear. You eventually determine what works for you.

In my case, I have wide feet (EE width), high arches, and a high instep. I’m attracted to the wide toebox and snug heelcup of the Altra’s, but even with that I need to wear thin socks in them to avoid them being too tight. For hiking, I want an all-synthetic, supportive, cushioned, high traction shoe.

Back to my experience with the Lone Peak Mid 4 RSM. First, the tear in the upper was totally a mishap, and I don’t feel that the new fabric is any less durable than previous versions. But it is still vulnerable to abrasion on the sides of the toebox.

My main issue is its funky fit (for me), which resulted in a constant flip-flop sound while hiking in them. I tried tightening them down as much as I could, switching to thicker insoles, and wearing thicker socks, but nothing worked. It was mostly an annoyance and did not result in blisters or anything like that. Finally, I did not notice any improved support or protection from the Mid version.

When I got the Low Mesh version midway in my testing, I immediately noticed that they were a better fit, provided more agility while hiking, and were simply more comfortable. I could also notice the Low version’s lighter weight; 3 ounces less per shoe.

After noticing a significant difference in the comfort and performance of the two versions of the Lone Peak 4, I dived into comparing details of the two shoes to try to account for the perceived differences. Notable differences in the Mid are taller shoe height (obviously), the lacing system at the top of the shoe, thicker laces, thicker padding around the ankle, a looser fit around the ankle, and an added exterior thick TPU band around the heel. 

So, the devil is in the details, so to speak – the Mid is a different animal compared to the Low. It’s not just the Low shoe with a little height added; it’s a different shoe.

I also dived into trying to figure out what was causing the flip-flopping effect. I thought it might be heel rise due to a looser heel cup, but when I measured the heel cup width of the two shoes the difference was negligible.

I conclude that the flip-flopping of the Mid version is due to the multiple design differences between the two shoes, which overall do not provide an enveloping fit like the Low.

The other upgrades in the new Lone Peak 4 are all good improvements. The static lacing loop over the instep does provide better cinching, which makes this trail running shoe much more stable while hiking across steep sidehills. Also the improved rock plate and traction outsole are distinct improvements.

Here’s the Lone Peak 4 Mid RSM and Low side by side, both in size men’s 12.

Here’s how the Lone Peak Low 4 (green) compares to the Lone Peak 3.5 (red). Both are the fabric (non-waterproof) version. The new version has a more aggressive outsole, although the old version is pretty worn down.


The outcome of my testing was a bit different from what I expected. For me, the funky fit, flip-flopping, and lack of improved support made the Lone Peak 4 Mid RSM a disappointment. When the traditional Low Mesh shoe arrived, my feet told me “I like these much better!”. Granted, they get wet easily, so they are not suited for hiking in snow and slush, but they are just fine for summer hiking where getting them wet is less of an issue because they dry out quickly.

I will continue to be a fan of the Altra Lone Peak because of their wide toebox, support, and comfort. However, my experience with the Mid version reinforced my preference for a low-cut shoe; I simply prefer the lighter weight, improved agility, good traction, and adequate support they provide. In this case a taller shoe didn’t offer any more.