Thursday, May 11, 2017

Review-Nathan Sports VaporKrar 12L and 4L race vests

Article by Dominick Layfield with Jeff Valliere

Editor's Note: Dom Layfield will be running the Western States 100 and UTMB in 2017 and as such is evaluating all kinds of gear for these races.

Nathan VaporKrar 12L and 4L Race Vests
Nathan recently launched a new line of hydration packs .  There are two male-specific versions, bearing the name of legendary ultra-runner Rob Krar, and two female versions, bearing the name of legendary ultra-runner Stephanie Howe.
The author at Leona Divide 50, wearing VaporKrar 12L.  Photo credit: Christopher Ferrier.
Nathan sent RTR both of the two male "VaporKrar" packs for review.  The larger, VaporKrar 12L ($180) has a nominal 12 liter capacity, and is supplied with a 1.8 liter hydration bladder.  The broadly similar 4 liter version, VaporKrar 4L ($150)is supplied with twin soft-flasks with extension straws.
The 12L version was reviewed by Dom Layfield; the 4L by Jeff Valliere.
First Impressions
Nathan VaporKrar 12L vest, front pockets loaded with soft-flasks and gels.
Dom: The vest/hydration pack is undeniably good-looking.  I liked the gray-blue color with fluorescent yellow accents and reflective markings.  The same light, stretchy fabric is used throughout the vest, although in places (on inside the back panel and on the inside of chest pieces) it seems to be doubled up and laminated with a slightly stiffer material in the middle.  No mesh or other textiles are evident.

The entire pack is soft and light and comfortable.  Soft enough that I had no problems wearing it without a shirt, and experienced no chafing.
VaporKrar 4L front is very similar to 12L.  Only difference are the simpler sternum straps.

Sizing quirks

The VaporKrar 12L and 4L race vests both comes in 5 sizes: XS, S, M, L, and XL.

Dom: Nathan sent a size 'M' in both vests.  For me (5'11", 155 lbs, 39" chest), this definitely felt a little too tight.

Dom: Initially, I was perplexed because there didn't seem to be any size guidance available anywhere, but a couple of days ago a size chart finally appeared on Nathan's product page.  However, I found this to be of questionable value.  It says to measure your chest circumference "at Sternum".  Mine measures 35" when I exhale and 37" fully inhaled.  According to Nathan, size 'M' should fit 36-38" sternum measurement.  Irrespective of details like whether measurement should be taken with full or empty lungs, the sizing guide seems off.  Wearing only a thin tech shirt, I could just about close fasten the two sternum straps when extended to their longest, and with the side adjustment straps (see later) loosened.  With more layers underneath the vest, it started to feel uncomfortably snug, and beginning to restrict my breathing.
VaporKrar sizing chart.  Both reviewers felt that Nathan's guidance needs to be corrected.  [Downloaded from Nathan website May 8, 2017]

Jeff:  Like Dominick, I found the sizing to be a bit awkward. At 5'10", 145lbs with a 38" chest, I am consistently a medium in other brands like Salomon, Ultimate Direction and Ultraspire. A medium however in the VaporKrar 4L is
a bit on the snug side, even when only wearing just a tech tee. Trying to fit this vest over multiple layers and/or a jacket would be pretty darn snug, if at all possible. When wearing the vest, the sternum straps are all the way extended and I have just a little bit of leeway with the top strap, but the straps are static (something I normally prefer when the vest fits correctly) and the materials of the vest are somewhat thick and have very little give. It is snug enough that I am always aware of it being snug, so ideally, I think a large would fit me better.

Until Nathan updates their size chart, RTR suggests buying a size larger than their chart suggests.

Rear Storage (12L version)
Storage is generous (for a lightweight race vest) and well thought out.  At the rear, working from inside to out, there is a large compartment for the hydration reservoir; then a small upper compartment with velcro closure, suitable for a phone or wallet; then a large (full length) compartment with zippered side entry; outside of that is another full-sized compartment with a generous elasticated upper entry (with velcro closure), suitable for rapidly stowing layers on the run.
Rear storage: closest to wearer's back is compartment for hydration reservoir
Next is a smallish pocket, suitable for wallet, phone, or emergency blanket.
Continuing to work outward, there is a large compartment with a long side zipper.
Outermost is a large compartment, rapidly accessed through the top, with elasticated entry secured with velcro tab.
I have no significant criticisms here.  For the most part, I think Nathan made excellent, sensible choices.

My only quibble would be that the side tensioning straps enter the back of the pack through opening on each side, attaching to another floating fabric partition.  This creates by default not one but two 'pass-through' pockets (one underneath the partition, one on top of it).  The arrangement seems needlessly complicated and confusing.  I'm not even clear whether the intent is to create a pass-through compartment at all, since almost anything except a rolled-up jacket would likely fall out.

Jeff: The 4L has significantly less storage than the 12L, but still feels generous to me. The main compartment doubles as a bladder sleeve (not included with the 4L) and is quite large, running the entire length of the vest. At the top is a smaller outer pocket the can hold a few smaller items like a light windbreaker, glove liners, hat, etc. and has a velcro tab to contain contents. At the bottom, is a pass through pocket, which, for me at least is tough to access on the move, but I can stuff a bottle or a windbreaker there and get to it while on the move.
'Pass through' compartment of VaporKrar 4L.  Although the 12L is similar, it has less fabric at the edge, making the space less useful for storage.
Front Storage
There are three compartments in each of the two chest panels.  Each side is (almost exactly) a mirror image of the other.
Front storage: upper pockets are big enough to hold a large (6") phone with protective case, although one reviewer found carrying a phone in this pocket uncomfortable.
Up high is a long (8"), thin pocket, with side zipper.  These are neatly designed so they remain narrow (2-1/2" to 3") when empty, but have an extra fold of fabric which allows them to accommodate larger objects.  I was able to squeeze in a large cell phone (Nexus 6P) in a protective case.  A Nexus 6P is almost identical in size to a iPhone 7 Plus (In case, it measures 162 x 81 x 9 mm). Personally, I rarely run with my phone, but I understand this is an important consideration for some.

Dom: The extent of my testing to-date has been to check that my phone fitted in the pocket.  I haven't actually run with it!  However, with the 4L version (which appears to have identical front construction) Jeff found that carrying his phone in this pocket was uncomfortable, and I have no reason to think the 12L would be different.  The lower bottle pockets are plenty big enough to hold a phone, and of course, there is plenty of (less quickly accessible) storage in the back.

Lower front pockets (empty)
Lower front pockets are perfectly sized to hold a softflask and gels
Below this is a long, thin pocket with elasticated (gathered) top entry, clearly designed to hold soft-flasks.  The 12L version of the VaporKrar vest is not supplied with Nathan's own soft-flasks, but I tested using the widely available 600 ml Salomon/Hydrapak ones, and found they fit perfectly.

On the outside of the soft-flask pocket is a smaller pocket with elasticated top entry (and velcro closure), which is perfectly sized for gels and similar smaller items.

The only asymmetry is that the upper, zippered pocket on the left side of the chest also has a tiny inner pouch (about 2" square, suitable for holding pills or a small key fob) and an emergency whistle on a short lanyard.  The whistle doesn't seem to be detachable.
Upper left front pocket also holds an emergency whistle and has a small inner pouch for pills.
Again, everything is well thought out, and appropriately sized.

Jeff: Front storage of the 4L is identical to the 12L. I pretty much always carry my iPhone 6, as I am often on call as a dad, use it as my camera, gps, MP3, etc..., so phone storage/access is important to me. I can fit my phone (with Lifeproof case) in either top zippered pocket, as they are pleated and stretch generously, but when running, I find that the hard edges of the phone case chafe and awkwardly press against my collarbone. Instead, I choose to store my phone in one of the bottle pockets, or in one of the lower pockets (even though the phone does not fit all the way into the lower pockets). Unlike the 12L, the 4L has side pockets built in that could fit a few gels each, glove liners, or other small items. Unfortunately however, the pockets are not so cleverly positioned underneath the adjustable side retention straps, thus minimizing usable space, compressing anything in the pocket and making it all but inaccessible. Routing the adjustment strap through the pocket, as is the case with the some of the Ultimate Direction packs would have been a great improvement and gone a long way toward usability of these side pockets.
VaporKrar 4L has side pockets that the 12L version lacks.  Unfortunately, the side straps run over the top of the pocket, hindering access and making the pockets almost unusable.
Hydration Reservoir (12L)
The VaporKrar 12L is supplied with an unusually-shaped reservoir.  It necks in in the middle, giving it an hourglass shape.  It also has a extra piece of plastic film that connects the front of the bladder to the back, acting as a baffle.  The baffle is particularly elaborate as (presumably to allow the bladder to be turned inside-out for cleaning and drying) it is detachable on one side.
The VaporKrar 12L comes with an unusal hour-glass shaped hydration reservoir made by Hydrapak.
The reason for the strange shape and baffle within the reservoir is purportedly to stop liquid sloshing around during fast running.  I was skeptical that this would accomplish very much so I filled both the Nathan-supplied hourglass bladder and a standard Hydrapak bladder and took them both for a run.  When completely full there was minimal difference: no sloshing within either bladder, but the entire bladder did bounce up and down, regardless of the tension on side straps.  Similarly, when empty (or nearly empty), there was no difference.  But when about half full, the hourglass/baffled bladder did seem to be a little more resistant to up/down motion of the liquid inside.

In addition to the unusual reservoir, the overall design of the pack -- specifically the way it applies tension around the reservoir -- keeps the sloshing to a minimum.  In this respect, it is close in performance to my 'gold standard' of hydration packs: the Camelbak Classic, in which sloshing is minimal, without any funky baffles or convoluted shapes.

Water bottles (4L)
Water bottles supplied with the VaporKrar 4L have an innovative design with extension straw.
The 4L version of the VaporKrar is supplied with two hand-held soft-flasks.  The design of these is very interesting: they have an extension straw to allow hands-free drinking.
The mouth of the soft-flasks supplied with the 4L is too soft, making it hard to screw the cap on correctly.
Jeff: Instead of a bladder being included like with the 12L, the 4L comes with 2 12oz. soft flasks made by Hydrapak. Hydrapak makes some great flasks, but these particular ones are nearly unusable, as the mouth of the flask is quite flexible, thus making it nearly impossible to properly thread the cap onto the bottle, causing significant leakage. Even being very careful and deliberate, I cross thread the cap at an awkward angle nearly every time.

Magnetic hose clip
On the hydration hose there is a little clip-on magnet which connects to a metal disk integrated into the upper right sternum strap.  This is a very handy feature, although the receptacle cannot be relocated, so you're stuck with the position that Nathan deemed best.
Hydration hose comes with a magnetic clip that connects to receptacle on sternum strap.  This is present on both versions of the vest.

Even though the 4L version does not come with a hydration reservoir, the magnetic hose clip is still there.

In Use
Dom: In every day use, I found the VaporKrar 12L to perform excellently.  As with a lot of items (like toasters, fridges, etc.) when something is well-designed, it becomes unobtrusive.   I mostly forgot I was wearing the vest.  Nothing much about it annoyed me.
The author racing at Leona Divide 50-miler wearing VaporKrar 12L  Photo Credit: Christopher Ferrier.

Dom:  I used it at the recent Leona Divide 50-mile race.  Race day was unusually hot (low 90's F) which provided a great opportunity to really load it up.  I didn't have cold-weather clothing or waterproofs to stash, but I did completely fill the reservoir and also used both front pockets for soft-flasks of water.  Everything worked perfectly.  The additional weight of the soft-flasks didn't cause the vest to shift around, and the low front pockets were perfect for gels.

Dom: I haven't yet had the opportunity to test the VaporKrar 12L at longer distances, like a 100-miler, where I would likely also be wanting to stash a headlamp, beanie, extra layers etc.

I don't typically use poles while running, but for those of you that do, the pole storage on the VaporKrar seemed to perform well in my short test.


First let me preface this section by saying that I was impressed with the VaporKrar vest.   It performed extremely well throughout my testing.  However, I'm the sort of detail-obsessed guy who can always find something to nitpick about, so here goes...

1. No side storage in 12L version; 4L side pockets flawed
The side panels connecting the front to the back are already double-walled, and it seems strange that Nathan didn't take advantage of this to offer an extra pair of quick stash pockets on the side of the 12L vest.

Dom: Obviously, this was an intentional decision by Nathan.  But I like having easily accessible side or low rear pockets that I can stuff things into without having to take off the pack.   The "pass-through" compartment at the back it is hard to reach, and could be used to hold a rolled-up jacket.  But it is shaped such that almost any small object will fall right out.  The 4L pass-through is slightly different and a little better in this respect.

The 4L version of the vest does have side pockets.  However, as discussed above, the side strap run right over the outside of the pockets, severely compromising their usefulness.

2. Smelly
The stretchy polyester fabric used throughout the pack gets smelly.  You'll want to wash this regularly, or find yourself being ostracized during group runs.

3. Excessive use of Velcro
There's too much velcro.  It is mostly used to provide extra security to stop items bouncing out of pockets, but I found that the velcro made it occasionally hard to get things in and out, and additionally snagged items of clothing.  It annoyed me enough that I have been tempted to try to unstitch it.
The velcro loop to hold top of hydration reservoir on VaporKrar 12L was surprisingly difficult to use, and frequently snagged on adjacent loop.

Secondly there's a velcro loop that is used to retain the top of the hydration reservoir.  In practice this proved fiddly to undo with sweaty fingers: with numb or gloved fingers, I suspect it would be really annoying.  I've also found that the velcro is already catching on and fraying the adjacent loop for hanging the pack. There's really no need to make the simple task of retaining the top of the reservoir so complicated.  I much preferred the metal tab used in the UltraAspire Alpha pack, for example.

4. Too many, non-removable straps
The twin sternum straps of the pack are fairly heavy-duty, each zig-zagging between the two chest panels in a 'V' shape.  The goal is presumably to stop relative motion of the sides, particularly up-and-down.  They do this admirably.  And they are easy to slide up and down.  They're also big enough that I feel confident that I could operate them in the dark, with gloves on.  (Which remains my major criticism of Salomon hydration packs, whose sternum straps are absurdly fiddly, and all but impossible to manipulate in the cold.)
Sternum straps of the VaporKrar 12L work well and are rock solid, but arguably excessive and non-removable.  Note magnetic hose clip receptacle on upper strap.
But I felt that having two straps was overkill: I wanted to remove one to see if I noticed any degradation in performance, but the only way to remove the straps would be to cut them off entirely and irreversibly.
Sternum straps on 4L are more conventional.  The size is good, and the straps are inelastic.

Similarly, on each side of the 12L vest are two straps which allow the distance between the front and back to be adjusted.  These seem superfluous.  I wanted to loosen them further, but because the vest was slightly undersized, they were already at their limit.  I would have liked to be able to remove them completely, but again the only way to do this would be to permanently cut them off.

The 4L has identical side straps, but in this case, the situation is worse because they interfere with the side pockets (not present on 12L vest).

5. Not as well-ventilated as competition

The stretchy polyester fabric used in both VaporKrar vests is light and breathable, and has laser-cut (LASER!) holes in certain areas to improve ventilation.  However, compared to other vests that make more use of open mesh fabric, ventilation is necessarily slightly compromised.

Jeff: The VaporKrar 4L is very well built, high quality and is sturdy enough to carry a full load with little flex or bounce. The thicker materials, while comfortable and durable, really soak out and are quite slow to dry. Though
many key areas of the pack are vented with a lot of small holes, this pack felt a bit on the warm side if temperatures were even in the 70's.

  • VaporKrar 12L weighed 266 g (9.4 oz) without reservoir, 
  • VaporKrar 4L weighed 220 g (7.75 oz) without bottles, 326 g (11.5 oz) with.

Dom:  I really liked the VaporKrar 12L.   While it doesn't really stand out from the field in any one area (except perhaps the lack of bouncing and sloshing), it does everything well, and doesn't have any real drawbacks.   I find hydration packs/race vests to be like running shorts: you only notice them when they don't work properly.  In all my training runs and one race (to date), the VaporKrar performed has admirably.

Dom's Score (VaporKrar 12L): 9.2/10
-0.25 for size misinformation (and limited adjustability)
-0.25 for lack of side pockets (and rear pass-through of dubious utility)
-0.1 for so-so breathability
-0.1 for excessive, non-removable straps (which a little short)
-0.1 for being slightly on the heavy side

Jeff:  Despite the fit issues, bottle issues, thick materials and unusable side pockets, the VaporKrar 4L is a very nice vest. I swapped out the bottles for others that I have that work much better and that made a huge difference.  There is not much I can do about fit, but have simply accepted it and do not use on days where I'll need to be layering up. Though a bit on the snug side, it generally works well for me if I don't over stuff the pack (or myself at breakfast). I find that the 4L is great for shorter runs to half day runs where I'll need a variety of essentials such as water, minimal layers, hat, beanie, some food, etc... It rides quite stable with a full load with no bounce and the materials, though slow to dry, are very comfortable against the skin and interact nicely with my typical running shirts.

Jeff's Score (VaporKrar 4L): 8.8/10
-0.3 for bottle leakage
-0.2 for fit (try on first, or size up if close to the upper end of suggested size)
-0.2 for slow drying materials
-0.3 for unusable side pockets
-0.2 for price (though the price is comparable to similar size vests, $149.99 is a lot in my mind given the fact that the bottles will need to be replaced and the side pocket storage is essentially unusable).

Women's specific versions of the two Krar vests, the VaporHowe are available
Nathan Sports VaporHowe 4L
Nathan Sports VaporHowe 12L
Dominick Layfield's Run Bio
Dominick Layfield lives in Southern California after several years in Park City, UT.  He is an avid trail runner who likes to race.  He holds a PhD in biomedical engineering from MIT, and has worked as a researcher in orthopedic biomechanics. So he knows the difference between a ligament and tendon :-).
In 2016, he raced, among others, the Angeles Crest 100 (2nd place), Scout Mountain 80K (1st place), and Georgia Death Race 68 miler (3rd place).  His latest achievement was first place in the dead of winter 2017 108-mile Spine  Challenger race in the UK, breaking the course record by an hour. He will be running both the Western States 100 and UTMB in 2017.
Jeff Valliere's Run Bio
Jeff is a former pro cyclist who now runs and climbs the mountains of Colorado. He has been top 5 Masters, top 25 overall, at the Pike's Peak Marathon several times, finishing 3d Masters this year. Jeff loves vertical accumulating more than 500,000 vertical feet per year, has climbed all the 14's and 200 of the 13's and has held FKT on several.  He often runs and climbs at night. Passionate about the sport but also the gear he has reviewed hundred of shoes for various magazines and sites and participated in product testing for many brands.  Formerly a bike mechanic he has recently worked in Satellite Imagery. He has twin 6 year old daughters who keep him ever busier yet.

The Nathan Sports Krar vests were provided at no charge. The opinions herein are entirely the authors. Photo Credits: Dominick Layfield, Jeff Valliere, and  Christopher Ferrier

Comments and Questions Welcome Below!

Purchases through the links below help support Road Trail Run . Thanks!
Men's here
Women's here


Jeff Valliere said...


Dan said...

Would either of you like to comment on whether these packs would be daily drivers for you, or would you prefer something else from UD, Salomon, Camelback etc?

Jeff Valliere said...

My daily driver is actually the Naked Running Band.

I take very few runs without it now, perfect for a few essentials I may need for an hour or two most of the year. It all really depends on the run, if I want more than the NRB, I use my 1L Sense set, then the Sense Ultra 8L, for longer days in the mountains or in Winter, then the UD AK 3.0. Not sure where the Krar 4L fits into the rotation yet I guess.

Matt said...

Thank you for the detailed review.

Did you try any hard bottles up front on the 12l pack? I like the 18oz Nathan Speeddraw bottles, but am not sure if they would fit in those front pockets and be comfortable.

I am not sure I am ready to hop on the soft flask train.

Ben Zuehlsdorf said...

I share similar thoughts here:

Anonymous said...

Any reason to look into this vest over the Salomon s-lab sense ultra 5 set/8 set?

Sam Winebaum said...

You would look into the Krar 12 over the 2 Salomon if you wanted to use a hydration bladder. Not really feasible in the Salomon you mention. The Krar 4 would be comparable to the 2 Salomon in terms of having 2 front soft flasks.

Jeff Valliere said...

Agreed, the VaporKrar would work much better than the Salomon Sense Ultra vests if using a bladder. The Salomon is not really designed to use a bladder, but even if you modified it to work, the Salomon vests do not have enough structure/support for that kind of weight, especially when running.

Anonymous said...

Not planning on using a bladder

Jeff Valliere said...

If you are carrying lighter gear, going fast, using in the heat and/or generally feel constricted by packs (or all of the above), I find the Salomon to be a better choice with its thinner materials, clothing like fit and light weight. If temps are cooler, breathability is less of a concern, you are carrying heavier gear etc..., the more substantial structure of the VaporKrar might be preferable. Don't forget Ultimate Direction though, they make some of the best running vests I have used.

Capacitor said...

Hi, great reviews.

I have a 4L VaporKrar, and I am struggling with using a bladder. The bladder I have is 2L,but doesn't take up nearly all the room in the main pocket. As a result, the bladder moves side to side a LOT, and the upper part of the bladder constantly slaps against my spine.

Do you have any specific recommendations for how to solve this problem? I have the right size (XL) vest, I am broad-chested, any smaller and the straps wouldn't connect.


Michael B said...

The latest sizing chart (4L) from Nathan seems to be different than what is in this review.

I'm having the opposite issue in that I measure 37 inches and I have to crank the medium size down as far as it will go. They now list medium as 39-41 inches.