The UltrAspire Spry 4.0 Race Vest. All photos: iRunFar/Kristin Zosel
Minimalist hydration pack lovers, you have reason to be excited if you’re in the market for a well-featured, familiar but updated 3.5-liter hydration pack that excels in hot weather but also fits sleekly under a warm winter layer or two when the Arctic blast has a firm grip on your area. Subtly and expertly revised, the UltrAspire Spry 4.0 Race Vest ($75) is even lighter than previous versions, while the front pocket functionality and overall comfort are improved. This is the third version of this pack that I’ve owned — version 1.0, 3.0, and now 4.0 — and it is by far the best, if for no other reason than I can now put any of my 17-ounce/500-millimeter soft flasks vertically in the front bottle pockets with complete confidence that they’ll remain in place.
The Spry 4.0 has lost nearly an ounce over the previous version, the UltrAspire Spry 3.0 Race Vest, and now weighs a mere 6.4 ounces (181 grams). My feeling is that this weight savings comes primarily from a change in the sternum clasps, and absence of two unnecessary bungees, because the 3.5-liter capacity remains the same. Even in its lighter rendition, the front pockets are larger and easier to use, thus further supporting my position that this is the best UltrAspire Spry Race Vest yet.
Shop the UltrAspire Spry 4.0 Race VestUltrAspire Spry 4.0 Race Vest Construction and Fit
A front view of the UltrAspire Spry 4.0 Race Vest.
The overall construction of the UltrAspire Spry 4.0 Race Vest is very similar in material and style to the Spry 3.0. As before, UltrAcool Light Mesh makes up the back and shoulder harness of the pack next to the skin. Providing a bit more comfort for the torso is a panel of honeycombed polyester mesh, which pads and protects the torso from bottles or any other items you place in the front pockets. This panel also creates a vertical drop in pocket, though I’m not certain what I’d put here.
Both materials are optimized for hot weather (Arizona and Colorado tested) and are excellent at wicking, not retaining, moisture — while remaining highly breathable. The pack is relatively smooth against the skin, and thanks to the sueded reinforced perimeter binding, risk of chafing is minimal. I appreciate that these materials slide easily over technical shirts and fleece layers alike without causing pilling or abrasion to the clothing, as I often will wear this when I need to add a warmer running coat over the top of the pack to keep my fluids and fuels thawed. The low-profile design is perfect on either end of the temperature spectrum.
Like former versions, the Spry 4.0 is a one-size-fits-most (chest sizes 26-48 inches/66-122 centimeters), with the primary adjustability coming from the two sweat-proof, non-stretch webbing straps on either side at the base of the pack. It takes a little bit of experimenting to find the right snugness of these straps in conjunction with the stretchy bungees of the Max O2 Sternum attachments at the front, but once I found the right balance, these straps stay put no matter what type of terrain or weather I’m running in, and any necessary fine tuning can be done by adjusting the bungees at the front.
While the straps aren’t always the most comfortable along the ribs, it is a very simple design that has been around from the first hydration packs of the 90s, and again, maximizes coolness in hotter weather. I haven’t found a great way of containing the tails of these straps, so perhaps don’t throw away those rubber bands around them that the pack comes with in shipping.
As I stated in my previous review, I really appreciate the Max O2 Sternum closure concept, because the stretchy bungees allow for full inhales and exhales even up the steepest of terrain without restricting the movement of the ribcage in the slightest. The improvement to this system on the 4.0 pack is the replacement of the two metal hooks and leather anchoring patches used in prior versions with sleeker, lighter, better-integrated, and rubberized hooks along the soft, lined perimeter rail — thus eliminating two of the potential chafe points of older models. Unfortunately, the hooks are still not moveable vertically along the rail, which means I continue to get gapping of the pack between the two sternal closures, but it’s not as pronounced as with the 3.0 version. Routing holes or pockets are still perfect for containing the bungee tails, thus preventing things from flapping around while cruising down the trail.
UltrAspire Spry 4.0 Race Vest Storage and Hydration
A side view of the UltrAspire Spry 4.0 Race Vest.
UltrAspire returned the two front bottle pockets to the vertical position on the UltrAspire Spry 4.0 Race Vest, and made them large enough to hold UltrAspire’s own 500-millileter soft flasks — and their semi-rigid ones — as well as any of the other taller Hydro Flask soft bottles you likely have lying around. No longer is there any concern about a bottle shooting out of a pocket randomly while running — or bending over to pet dogs — and if you don’t want to purchase new bottles, I’m sure you have ones that will fit!
Utilizing the vertical pocket orientation also allowed the extra bungee on either side to be eliminated in favor of the thin stretchy strip that sits just above the pockets, which provides an extra element of security for taller pockets or straw lids. This works flawlessly and even though the bottles sit a little lower than some packs, it still makes for easy drinking on the run without compromising the security of the bottles within the pack.
Overlying each bottle pocket is a stuff pocket that is now larger and easier to get fuel, headbands, trash, or other items in and out of, even with thin gloves on — another boost to the functionality of the 4.0 over previous versions. The sweat-proof magnetic closure pocket remains near the right shoulder, which is perfect for a small baggie of electrolyte pills or other little items you prefer to be a bit more secure. On the left upper harness is a four-way stretch pocket with a vertical bungee closure that can hold at least a smartphone securely, or whatever else you may need.
The posterior aspect of the pack appears unchanged. There is a hydration pocket with a bladder hanger large enough for a snugly fitting 1-liter bladder against your back, with a routing strip over the right shoulder for securing the tube. A sweat-proof pocket with vertical zip lays over the bladder pouch, which allows you to keep items like a small med kit, key clip, and wallet sweat-free and protected from the elements.
Lastly, a third four-way-stretch pocket with magnetic closure is stacked and capable of swallowing a wind jacket, atop which a laced bungee cord sits for attaching an extra layer. Everything stays close to the back and bounce free.
For a 3.5-liter pack, the functionality and capacity is pretty amazing. However, I feel like it is imperative the load is well-distributed between the back and the front, which is a bit challenging because of the inaccessibility — to me, at least — of items stored in the back while wearing the pack. If you have your fluids, phone, and some snacks all up front with nothing to counterbalance, it is difficult to avoid the forward slide and bounce of the items, unless you tighten the pack to what I felt was uncomfortable levels. Simply balancing the load is the key to comfortable running with this pack, perhaps more than some other minimalist packs out there.
UltrAspire Spry 4.0 Race Vest Overall Impressions
A side view of the UltrAspire Spry 4.0 Race Vest.
Overall, the updates to the UltrAspire Spry 4.0 Race Vest move it back into contention for best minimalist pack. The highlight for me is the return of the deeper vertical soft flask pockets that accommodate a variety of 500-millileter bottles with the overlaying larger stuff pockets. It’s just a better overall design for the positive runner experience — more functionality, ease of use, and zero worry of things falling out of the pack under normal ultra-trail user conditions. The 3.5-liter capacity is a sweet spot for many races, with somewhat frequent aid stations, and is a true workhorse for daily runs in the heat of summer — or even in the winter under a heavier layer, due to the slim-fitting design. Well done, UltrAspire, for truly dialing in an excellent minimalist pack.
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