The Seral is a lumbar-style pack that includes a high-quality 1.5-liter HydraPak hydration bladder in a lightweight, neatly designed package. This fanny pack has a well-organized storage system with two main pockets with interior organization compartments, and two convenient zippered waist belt pockets. The hydration bladder is easily accessible and scores well overall in our hydration rating categories. Combined with the smart design and construction you would expect from Osprey, the Seral takes home our Top Pick Award for lumbar packs.
On the go without shoulder straps to slow us down!
Ease of Drinking
The Seral Lumbar is equipped with a 1.5-liter lumbar style hydration bladder made by HydraPak and a HydraPak bite valve with a magnetic clip. We never had any trouble drinking from this system in our field tests, and appreciated the comfortable and effective bite valve. While we were satisfied with this performance, it didn't flow quite as easily as our top-rated CamelBak Crux hydration system. If you're a big gulper, you could swap out the HydraPak bite valve for a Crux mouthpiece, or you could consider the Osprey Talon 6, a lumbar pack with two handy squirt bottles for easier chugging.
The HydraPak hydration systems performed well during our in-home flow tests, confirming our field observations. If you're interested in another lumbar pack with a very similar high-quality HydraPak hydration system, but with a bigger 2-liter water capacity, take a look at the Dakine Hot Laps 5.
The Dakine model (left) has a 2-liter capacity, the Talon has a 1.2-liter capacity, while the Seral (right) has a 1.5-liter capacity.
The drinking hose for this pack wraps around the waist belt, and the bite valve attaches at the left hip with a magnetic clip. We found that this system was easily accessible while riding, though we would have liked if the magnet was a little stronger.
Ease of Filling
The Seral's HydraPak hydration system receives average scores for ease of filling. While it's easy to remove the bladder from its compartment, and the bladder has a large opening like other Osprey models, our testers found that the wide lumbar style shape of the bladder is a little awkward to work with. While this is certainly minor, it is ever so slightly more tedious than working with the less elongated shape of the bladder in the Dakine Hot Laps model.
We are pleased with how the hydration bladder on the Seral
has its own storage sleeve and hanging clip, minor luxuries on a lumbar style pack. Though this adds another tiny step to the removal and replacement process, it's an appreciated extra to help keep the bladder secure within the pack.
The Seral's hydration bladder includes its own storage sleeve and a hanging clip to help keep it secure.
The Seral ends up right near the middle of our overall comfort rankings but came in as our most comfortable lumbar pack. With different densities of foam on the back support panel, an easily adjustable waist belt, and wide, padded side pockets , the Seral can be dialed in for a snug and cushy fit. Like any lumbar pack, if you fill it with a heavier load, it may need to be tightened quite a bit to keep it from sagging down below. Luckily, you can tighten the waist belt straps by pulling from the outside in, giving your hips a nice firm hug.
The tradeoff with the Seral and any other lumbar pack is that by saving yourself from shoulder straps and a full back panel, it most likely means that you'll be trading that for a hot and sweaty lower back. While each of our lumbar packs has design features to mitigate this, it is likely an unavoidable part of this category. If you want to experience top of the line breathability and back ventilation, our Editors' Choice Platypus Duthie backpack and our highly ranked Osprey Syncro 12 both have impressively supportive and well-ventilated mesh back panels.
Though it only measures in with a 7-liter storage volume, this pack earned a respectable spot in our storage rankings with its well-placed pockets and organization. It also has handy tightening straps on the sides to help condense or secure your loads.
The highest volume lumbar pack we tested, the Seral has two main storage compartments with interior storage pockets, as well as two zippered waist belt pockets. While not a ton of storage compared to a regular backpack, this has room for a light jacket, your bike tools, some snacks, and your keys, wallet, and phone.
Coming in at a measured 1 lb, 2.0 oz, the Seral is actually the heaviest lumbar pack that we tested, but is only separated from the lightest lumbar pack, the Osprey Talon 6, by a mere 2.0 ounces.
If you want to get away from the lumbar packs but still keep the weight down, definitely check out the minimalist CamelBak Rogue or Camelbak Classic.
While it's the heaviest of the lumbar packs we tested, the Seral is only two ounces heavier than the lightest lumbar pack.
Ease of Cleaning
The HydraPak lumbar style bladder accompanying the Seral didn't score as highly in our cleaning rankings. Although the bladder was easy to remove and has a large opening, it also has two small circular welds in the middle of the bladder, presumably to help give the bladder shape and support. However, this made cleaning a bigger challenge than expected, because the bladder can't be open up all the way, and the circular welds leave spots in the corners of the bladder that are difficult to access. While the manufacturer states that this bladder is top rack dishwasher safe, we're not sure how effective that would clean the inside nooks and crannies after extended use.
While we were able to keep the bladder clean during our testing, we're not sure how much of an issue this may be long term. The more traditional shaped lumbar bladder on the Dakine Hot Laps doesn't have these welds, so perhaps a swap for a different bladder could be considered if needed in the future.
Our three lumbar packs (left to right: Hot Laps, Talon, and Seral) all tipped the scales right around 1 pound (not including water!). Note the circular welds on the Seral bladder that may make long-term cleaning a bit more challenging.
The Seral can be your go-to hydration pack if you're a mountain biker who wants freedom from shoulder straps, or if you're a hiker who wants a lighter design, the convenience of all the storage pockets, and the top-quality construction of Osprey products. If you're considering taking the plunge into the world of lumbar packs, the Seral is a solid, fully-featured choice.
The Seral could be your go-to pack for shorter outings.
With an $85 list price, the Seral is the most expensive of the three lumbar packs we tested, $15 over the list price of the cheapest Dakine Hot Laps 5L. With a more comfortable and adjustable fit, and more storage and organization options, we think that this makes the Seral a very solid value for your next (or first!) lumbar hydration pack.
The Osprey Seral comes with an effective hydration system, excellent comfort and adjustability, and a convenient array of storage pockets, all with only a minor increase in price and weight compared to other lumbar style packs. With these respectable features and Osprey's typical solid construction, the Seral Lumbar snags our Top Pick Award for lumbar packs.