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

Tuesday, September 16, 2014

First Look: Gossamer Gear 2014 Murmur Hyperlight Backpack

By Will Rietveld

Introduction and History

The Murmur is a frameless minimalist rucksack for ultralight backpacking. The 2014 version is generation 3 of this popular pack. The dimensions and volume remain unchanged: 2200 cubic inches (36 liters). The pack is available in only one size.

The original silnylon Murmur Gen 1 came out in 2008, weighed 7.5 ounces, and had wide, thick shoulder straps padded with lightweight foam or your spare hiking socks. It even had a pair of side compression straps.

The 2012 Gen 2 Murmur is made of 140 denier Dyneema Gridstop and silnylon, has an Over the Top flap (no pocket), and thinner shoulder straps. The pack gained 1.5 ounces, but added useful features and durability.

Now the Gen 3 2014 Murmur is being introduced. This version is constructed of lightweight and durable Cordura high-tenacity nylon 6-6 ripstop nylon and Robic high-tenacity nylon, has thin perforated foam shoulder straps, replaces the Over the Top flap with a drybag closure, and adds hipbelt wings with pockets. The weight by my scale is 10.85 ounces without the provided SitLight pad and shock cord system. So, the latest Murmur has gained another 1.85 ounces; what are the changes and how much has the pack been improved?

The new 2014 Murmur backpack is unchanged in dimensions and volume and is available in one size. The weight has increased 3.3 ounces from the original.


The fabric used for the body of the new Murmur is 20-denier Cordura high-tenacity 6-6 ripstop nylon, the bottom is 100-denier Robic 100% high-tenacity nylon. These fabrics are lighter and more durable than the previous 140 denier Dyneema Gridstop fabric. Why? -- Because Dyneema Gridstop fabric is ordinary nylon 6 with a grid of high-strength Spectra fibers for strength. High-tenacity 6-6 nylon is industrial strength and highly abrasion-resistant.  If you are interested in learning more about these fabrics, Google “6-6 nylon” and “Robic fabrics” to get the details. There is a big difference between ordinary nylon 6 and high-tenacity nylon 6-6 and Robic.

The following photo sequence shows important details of the new Murmur.

The frontpanel has the same pocket design as previous versions. The big front pocket is a new more durable Darlington Mesh; fabric panels with lashing loops are attached to the mesh. Trekking pole holders have been added on the bottom left and removable tool loops on the upper body.

The backpanel has a thin Power Mesh for the pad sleeve. Note that it absorbs water (and sweat) as shown. A SitLight pad is included with the pack, which can be removed and used as a sit pad on breaks.

Side view: the side pockets are fabric and stretch mesh (same mesh as the front pocket), and are fairly tall. With the pack on, a water bottle can be inched out and replaced in the side pockets, but I would not rate it as easy. Note that there are no loops sewn in the side seams to attach a shock cord or compression system.

The top has a new drybag-type closure that replaces the Over the Top flap on the previous version. One side has a stiffener to facilitate rolling the top down. It’s held down with two side straps (see previous photo); their ¾-inch width is a bit on the heavy side for an ultralight backpack.

The bottom of the pack, including the bottom of the side pockets, is a 100% high tenacity Robic nylon fabric, which is very abrasion resistant. The hipbelt wings are attached with clips, so they are removable. There are two attachment loops, so the pack torso length can be shortened if desired.
Close-up view of the front and side mesh pockets.
The hipbelt wings each have a zippered mesh pocket. Note the clips that attach the hipbelt to the pack, and the second loop 2 inches higher to shorten the pack torso length.

Trekking poles attached to the pack’s trekking pole holders.
A folded ThinLight pad (about 3 ounces) in the pad sleeve adds a bit more weight than the provided SitLight pad (1.75 ounces), but it’s more versatile.

The new pack’s shoulder straps (and hipbelt wings) are padded with a thin perforated Wall Mesh, which should be very breathable.


Initial Testing and First Impressions

I carried the new Murmur packed with weights of 10, 15, and 20 pounds on seven day hikes, one of which was an ascent of a 13,000’ peak. The other hikes were my daily 5 mile walk up a local mountain. Following are my initial impressions.

The new Murmur comfortably carries loads up to 15 pounds; it’s less comfortable at its limit of 20 pounds. This agrees with Gossamer Gear’s specifications. The reason for its reduced comfort with heavier loads is pack torso collapse, which puts more weight on the shoulders, and the thin shoulder straps distort and do not spread the weight.
This photo shows the exact same load in the original silnylon Murmur. The shoulder straps are wider, thicker, and more supportive. As with any frameless backpack, pack torso collapse still occurs, putting more weight on the shoulders, but the wider, thicker shoulder straps in this case spread the weight over the shoulders, substantially increasing comfort.
The new Murmur’s hipbelt wings, padded with the same Wall Mesh, are no better than the shoulder straps; they collapse with heaver loads and do not spread the weight. I found that the ordinary webbing waist strap on the original Murmur is just as comfortable.

  • The new Murmur effectively uses the latest high-tenacity nylon fabrics and mesh to enhance durability while minimizing weight.
  • Small webbing loops in the side seams have been eliminated, so the pack does not have any volume compression capability. On previous versions I was able to run thin cords with cordlocks through those loops to create a compression system.
  • I really like the new drybag-style top closure; it’s easy to use, keeps water from entering the pack, and tightly secures the top.
  • The trekking pole holders are a nice feature and add little weight. There are many times on a backpacking trip where I want to stow my poles and have my hands free.
  • The Murmur is available in only one size. I measured the pack torso length at 18.5 inches (center of hipbelt to shoulder strap attachment), which translates to a size Medium. Connecting the hipbelt wings to the upper loops results in a pack torso length of about 16.5 inches for shorter hikers. I found the pack to be a bit too short for taller hikers like me, but usable with lighter loads.
  • Overall, I like all of the changes in materials and design of the new 2014 Murmur, except the very thin padding in the shoulder straps and hipbelt wings. When I compared the new pack with the original Murmur’s thicker/wider shoulder straps, I found the original pack substantially more comfortable carrying the same 20-pound load. Also, the new version does not have any volume adjustment capability as previous versions did.


Specifications and Features

Gossamer Gear (www.gossamergear.com/)
2014 Murmur Hyperlight backpack
Sizes Available
One size (Medium), adjustable to Small
2200 cubic inches total (36 liters)
Specified Weight
Minimum weight 8.5 oz; weight with hipbelt 9.2 ounces; total weight 12.7 oz
Measured Weight
Minimum weight 8.65 oz; weight with hipbelt 10.9 oz; total weight 13.65 oz
Pack body is 20 denier Cordura high-tenacity ripstop nylon coated  one side with silicone and the other with a PU/silicone blend; bottom is 100 denier Robic 100% high-tenacity nylon; front, side, and hipbelt pockets are Darlington stretch mesh; pad sleeve is Power Mesh
Stretch mesh front and side pockets, front pocket has attached lashing loops, trekking pole holder, ventilated foam padded shoulder straps, drybag top closure with 2 side straps, interior hydration reservoir hangers and two hose ports, detachable padded hipbelt wings with zippered mesh pockets, 2 attachment heights for hipbelt wings, backpanel sleeping pad sleeve with SitLight pad included, 2 tool loops, ice axe loop, haul loop

 Questions for Readers

I have been pondering the following questions, and hope that you can enlighten me. Your responses will help me keep up on current trends.

  1. Does anyone use the virtual frame technique anymore? That requires a closed cell foam pad. With the availability of LW comfortable inflatable sleeping pads, it seems like most hikers are adopting them, which makes it difficult to create a virtual frame. How do you create pack rigidity, or not?
  2. When you use an UL frameless backpack, like the Murmur, what is your initial weight? How comfortable is that weight in a frameless backpack, or do you go to a different pack for those weights?

After further testing of the new Murmur on backpacking trips I will add additional comments to this article and convert it to a review, stay tuned.

Saturday, September 13, 2014

GEAR REVIEW: Six Moon Designs Flight 40-FKT Backpack

By Will Rietveld


When I started this review in 2014 the Flight 40 was offered with two harness options -- traditional shoulder straps or a vest harness. I opted for the vest harness. Since then, to simplify things, SMD has split the original Flight 40 into two separate models. The Flight 40 Backpacker and the Flight 40 FKT. The difference between the two models is that the Flight 40 FKT (tested here) utilizes the Vest Yoke, While the Flight 40 Backpacker uses a more traditional standard Shoulder Yoke. The two packs now have a bungie attachment system on the front instead of the daisy chain on my test pack.

The main updates in the 2015 Flight 40-FKT are as follows:
  •  Adjustable and removable harness. You can choose either the Vest or Standard Shoulder Straps.
  •  Seven different harness options available (4 vest harneses and 3 standard harneses), along with 8 different hip belts. This gives the Flight 40  63 different possible configurations.
  •  SMD now uses  a single bag, vs the dual sizes of before. The volume of the pack is now 44L (vs. 48L before) for the M/L version. The volume listed does not include any of the pocket storage.
  •  Side pockets are now much deeper and have a closure at the top.
  •  A removable hydration is now included.
  •  Features like hip belt pockets, etc. are included in the standard price.
  •  Several new color options are available.

Following is my review of the pre-2015 model:

Six Moon Designs has reinvented and consolidated their backpack line down to two models – the Fusion and the Flight – each in two size capacities.

The Fusion 50 and 65, with a sturdy frame, adjustable torso, and capable suspension are sub 2.5-pound backpacks designed to satisfy the needs of most lightweight backpackers.

The lighter weight Flight 30 and 40 backpacks have a Delrin peripheral loop frame that is anchored to a weight-dispersing hipbelt, and features a unique vest harness. These packs offer extra comfort for backpackers at the lower end of lightweight or the higher end of ultralight.
The vest harness is what triggered my interest in the Flight. Earlier this year I tested the Ultimate Directions Fastpack 20, which also has a vest harness, and was impressed with its carry comfort and freedom of movement from not having a hipbelt. It felt like I was wearing the pack. But a hipbelt-free pack is only comfortable up to a certain point, about 10 pounds.

Nevertheless a vest harness is a refreshingly innovative feature for a backpack, and intrigued me enough to test a backpack with that feature. As you will see the Flight has numerous complementary features that add up to a very comfortable and capable backpack.

 Specifications and Features

Note: the specifications below are for the pack I tested. The weight and some of the pack details have changed on the 2015 version. Go to the Six Moons Designs website to see the current specifications.

Six Moon Designs (www.sixmoondesigns.com)
Flight 40
Sizes Available
S/M, M/L; size M/L tested
S/M is 44 liters total, M/L is 48 liters total
Specified Weight
S/M is 30 oz; M/L is 32 oz
Measured Weight
31.85 oz for size M/L
Pack body is 210 denier Robic, body contact areas are DriGlide, high wear areas are 410 denier PU coated nylon ripstop pack cloth, pockets are high-tenacity 4-way stretch nylon
Delrin rod peripheral frame, vest harness with 6 pockets and two point attachment, 2 sternum straps, load lifters, stiffened removable hipbelt with 2 zippered pockets and 4-pull tightening, hipbelt stabilizers, 2 front stretch mesh pockets, front daisy chain and ice axe loop, side zig-zag compression straps, extension collar, drybag top closure with top compression strap, interior zippered security pocket.
Now $220

The new Six Moon Designs Fusion 40 backpack actually has 48 liters (2900 cubic inches) of volume (which includes the extension collar and pockets) in size M/L, and weighs 32 ounces (2 pounds). The smaller volume Flight 30 (not shown) has 36 liters (2200 cubic inches) of volume in size M/L and weighs 21 ounces.



The following photo series shows the Flight’s notable features and details.

The Backpanel View shows the business side of the Flight. The center is well padded against the backbone. The shoulder straps flare out at the bottom to create the vest harness with two sternum straps. It has a two-point attachment to the pack body. The vest harness has six pockets, two of them zippered. The pack has a total of 10 exterior pockets.

Close up of the vest harness, with red bandanas inserted in the three pockets on each wing. It connects with two sternum straps.

Inside the pack, a peripheral Delrin rod is anchored to a high density polyethylene (HDPE) reinforcement attached to the back of the hipbelt. There is one zippered mesh security pocket on the inside. The pack does not have a sleeve for a hydration reservoir, but there are two loops for hanging one.

The wide padded hipbelt has a thin sheet of HDPE under the outer skin to provide stiffness and distribute weight. It’s tightened with a four-pull system connected to one central buckle. The HDPE layer in the hipbelt has a 6-inch cutout at each end, which allows the hipbelt to wrap and tighten around the hipbone. The hipbelt pockets have a large capacity, a big plus.

The pack’s frontpanel has two large stretch nylon pockets that wrap around the sides, and a combination daisy chain, lower ice axe loop, and upper top compression strap down the middle.

Each side of the pack has a four-point compression system that tightens with one pull. Note that a Platypus hydration system fits nicely in a side pocket.

The top has a 10.5-inch extension collar with a drybag-type closure and top compression strap.

The bottom of the pack, and other abrasion areas, are 410 denier pack cloth. The pack body is 210 denier Robic fabric. Note that the main shoulder strap attachment is to a wing on the bottom of the pack; the other attachment is to a wing located at the top of the side pockets.


Preliminary Testing

I tested the Flight 40 for this First Look article by carrying it on day hikes with 20, 25, and 30 pounds of weight. I loaded the pack with an old sleeping bag to fill it out, and placed 2-liter bottles of water high against the backpanel to simulate a backpacking load. Each hike was about 5 miles and took 2 hours.

My initial impressions of the Flight 40 are as follows:
  • Note that the actual volume of size M/L is 48 liters, not 40 liters.
  • In spite of its lightweight peripheral rod frame (see photo 4), the Flight is a capable load hauler. It easily and comfortably carried everything I put in it, up to 30 pounds. It gave me the impression that it is capable of carrying even more weight, if I am. For a 48 liter pack, the most a hiker is likely to carry is 25 to 30 pounds.
  • Its load carrying ability comes from the peripheral rod frame that is solidly anchored to the back of the hipbelt in the lumbar area, in combination with a stiffened hipbelt that spreads the weight, plus a bifurcated hipbelt that wraps around the hipbones. The pack effectively transferred all the weight to my hips and the hipbelt stayed on my hips, which is remarkable for a 2-pound backpack.
  • I really like the vest harness, it makes the pack feel like it’s being worn rather than carried.
  • I also like the six stow pockets on the vest harness. They are made of stretch nylon and are handy for a digital camera, snacks, or anything used often on the trail. Two of the pockets are zipped.
  • Further, I also really like the large hipbelt pockets, which are the largest attached pockets I know of.
  • Some hikers will miss a hydration sleeve; the Flight doesn’t have one. That doesn’t bother me since I use a 1-liter Platypus flask based hydration system in a side pocket, which is lightweight and convenient. The side pockets on the Flight are perfect for that arrangement.
  • One thing I miss on the Flight is a large stretch mesh pocket on the front of the pack. That’s where I put a large turkey roaster bag containing all of the items I want to keep handy on the trail. Fortunately, that bag of stuff fits into the other side pocket. Overall, however, there seems to be less pocket volume on the front of the Flight, compared to a conventional design with one large front pocket plus two side pockets.
  • The middle strip on the front of the pack measures 4.5 inches wide and has a daisy chain plus 8 attachment loops, enabling the Flight to easily carry items lashed to the front of the pack. For extra capacity, one could attach a tall, narrow gear bag to the front.
  • It is not easy to reach and replace a water bottle carried in a side pocket. The pockets are deep, large, and contain a compression strap within. One is likely to have other items stuffed in the pocket, plus the compression strap interferes, so inserting a bottle back in the pocket (with the pack on) is the challenge.
  • The Flight is built of bomber fabrics. They are very durable and will last a long time, but from a lightweight point of view, they are overkill. The counter argument is that heavier fabric doesn’t contribute much extra weight to a backpack, perhaps 3 to 4 ounces in this case; most of a pack’s weight comes from the frame, reinforced hipbelt, straps, and connectors. 


Field Testing

I carried the Flight 40 on several multi-day backpacks loaded with 21-23 pounds of lightweight gear.

  Although the Flight 40 would seem to be too small in volume for lightweight backpacking, its actual volume (in size M/L) is 48 liters, and it in fact has plenty of volume for a multi-day trip using a true lightweight gear kit. That assumes good gear choices and no unnecessary extras.

This pack's load carrying capacity is indeed remarkable, considering the pack's minimal lightweight frame and overall light weight. It carried the stated loads comfortably all day. That capability is due to a combination of a lightweight Delrin rod loop frame that is anchored to a supportive hipbelt with a four strap tightening system and cutout that molds the hipbelt to your hip bones. This pack is capable of transferring most (if not all) of the pack weight onto your hips.

I tested the pack with the vest harness option (now the FKT model). The vest harness with two sternum straps helps to distribute weight so overall it feels like you are wearing the pack rather than carrying it. The vest also adds lots of pockets to keep things handy. And the hipbelt pockets are the largest I have seen and also hold a lot of stuff.

This is a pack you will want to use with a hydration system because a water bottle in a side pocket is not easily reachable with the pack on, and part of the side compression system is inside the pocket so it is hard to insert a water bottle with the pack on. There is no hydration sleeve inside the pack, so a hydration reservoir would either need to go inside at the top of the load (there are two hose ports) or in a side pocket. My preference is the latter, for easier access and easy monitoring of how much water I have left.

The side stretch mesh pockets are large and hold a lot, but if you use one for carrying water, only limited outside pocket space if left for gear. I personally missed having a large stretch pocket on the front of the pack, along with two side pockets. I like to put all of my smaller items in a large turkey roaster bag (or other dry bag) and stuff that in a large stretch pocket on the front of the pack, but the Flight 40 didn't give me that option. I was able to stuff a smaller version in a side pocket (with a hydration reservoir in the other), but it was less then ideal. The daisy chain in the middle (now a bungie attachment system) allows one to strap a gear bag (or other gear item) onto the front of the pack, which would work okay.


Overall the Flight 40 is a very capable load hauler for its light weight, and I consider its volume to be ample for a multi-day backpack with lightweight gear. Many backpackers fear getting a pack that turns out to be too small in volume, but frankly you are better off to know the volume of your gear kit and match the size of your pack to the size of your load. A right-sized pack that is completely filled carries much better than a oversized pack partially filled. It you must purchase a larger pack "just to be sure its big enough", get one with a good compression system so you can adjust pack volume to get a tight pack no matter the load size. For that approach the Flight 40 is a good choice; it has an excellent side and top compression system.
My main issue with the Flight 40 is the outside pocket design. Granted, a pack designer needs to choose a single design that will please a majority of buyers, and then buyers need to decide if it meets their needs and preferences. I personally prefer a three pocket design that covers the sides and front of the pack with pockets. Other people like a "cleaner look". You need to make your own decision.

Other than the pocket design, I like everything about the Flight 40. Its an amazingly capable and comfortable backpack on target for a true lightweight backpacker.

Thursday, September 4, 2014

A Technique for Using a Steripen with a Hydration System

By Will Rietveld

My (current) favorite lightweight water purification system is the rechargeable Steripen Freedom, a 2.65 ounce (without carry case) device that purifies water with UV light. Why? – Because there is no wait time or sucking through a filter, just treat and drink.

I prefer to use a lightweight hydration system carried in a side pocket, but the flask has a narrow opening, which is not amenable to using a Steripen. The Steripen requires an open container or wide mouth bottle to wave the device around in the water.

So how do you use it with a hydration system, in ultralight style, which means minimal extra weight?

My ultralight backpacking friend Tom Galbraith came up with a clever and simple solution, described below. Here’s a photo of Tom on a recent backpacking trip two weeks after he bicycled 1700 miles on the Continental Divide road route. Credit for the idea goes to Tom, and I show the method here with his permission.

The technique is to use a gallon size zip-lock bag to scoop up water, treat the water in the bag with the Steripen, then transfer the water into your hydration reservoir. We like to use a Platypus flask.

Equipment needed is a Steripen, 1-gallon zip-lock plastic bag with slider closure, and a flask.

Scoop up water into the plastic bag. It’s easy to do while holding the bag open with two hands. I often treat 2 to 3 liters at a time and share the treated water with my hiking companions. For mountain hiking, I usually carry 1 liter or less to minimize weight.
Treat the water with the Steripen, which uses UV-C light to sterilize organisms. The Steripen Freedom uses a 48 second cycle to treat 1 pint of water, so multiple cycles are required, depending on the quantity of water. Simply dunk the Steripen into the water (it turns on automatically) and wave it around in the bag.

Transfer the treated water into the flask. If you are doing it alone, it helps to open the slider on the zip-lock about 1.5 inches, lay the zip-lock bag over your leg to support it, and pour into your flask held with the other hand.

This technique is a head-slapper in its simplicity and adds only a fraction of an ounce to your pack, besides the Steripen.

I have tried just about every water treatment and hydration system available, and this system is my current favorite. Its not the lightest -- Aqua-Mira drops or tablets are lighter -- but I like the convenience of fast treatment with the Steripen and being able to drink on the fly with the hydration system. In the mountains, where water is abundant, I treat and carry a liter of water at a time, which is a good balance of light weight and convenience.