A while back, Hydrapak offered us the chance to test out their $41.99 Flume hydration pack - a lighter weight (257g), lower profile, two-liter model designed with the needs of cyclists in mind. Since we were not terribly familiar with the brand, a run of the mill hydration system is what was expected…but nothing could have been farther from the truth. As soon as the pack arrived, it was clear this was not some knock-off pouch with a hose, but rather a well thought out hydration system with several design improvements that made it both easy to use and to maintain. One of the most obvious improvements is the use of a bladder which opens from the top – something common to the entire Hydrapak line. Not only does it make the pack easier to fill and clean, but it also allows the bladder to be turned inside out for faster drying. The Flume also features a well designed mouth piece which provided a steady stream of liquid without excessive biting or sucking. Its round shape also means there’s no sweet-spot – in my tests the valve provided near equal fluid flow where ever I bit down. Hydrapak has also integrated an innovative clear plastic valve / coupling system into the bladder which allows the supply hose to be easily attached and detached. In addition to virtually eliminating connection related leaks, the clear design makes it easier to see if anything has accumulated in the valve itself.
Before testing the Flume I would have probably walked right past a Hydrapak display in favor of a better known brand…but not anymore. The Flume’s well designed features made it a pleasure to use, and best of all…easier to keep clean. In fact this is the first hydration pack bladder which I don’t store in my freezer. In the future, Hydrapak is on our hydration pack A-list for sure.
Click on “Continue Reading” below for a far more detailed description of the pack and the tests we put it through.
Pack Construction & Use
Solid two pocket design – one for bladder and one for gear. The gear pocket runs about 80% of the pack length and will fit about 80 cubic inches (1.3L) of loot. When not in use, it lays nearly flat, and I barely knew it was there. Another good feature is the no-snag zipper which reduces the chance of the zipper sticking. While the Flume does not have the Air Scoop ventilation system found on other Hydrapak designs – probably because it would add too much bulk to this streamlined pack – a micro-chambered materiel sewn into the shoulder straps and backing seemed to do a reasonable job of wicking away perspiration. Like other packs, the Flume hydration hose can be mounted on either the right or left side. Hose-flap is tamed using Hydrapak’s Quick Draw system which allows the supply hose to be quickly tacked to a shoulder strap using Velcro.
Gear Pocket
Back View With Bladder
No Snag Zipper
Strap Materiel
Bladder Construction
The clear Flume bladder is very different from other hydration packs I have tested. Instead of a circular fill-cap, the bladder has a wide mouth roll-top closure which secures using Velcro. At first glance it looked like the bladder could leak, but several tests which included turning the full bladder upside down overnight, as well as forcefully squeezing it could not get it to shed a drop. In fact I am pretty sure the bladder would have burst before it leaked. One issue with Hydrapak’s top loading system was clearing excess air from the pack. Its not that it can’t be done, it just requires a different technique than I was used to. In the past, with screw type bladder closures, I would lay the bladder on a counter (with the fill-cap slightly undone), and press until liquid started to leak. Once it did, I would screw the cap tight, leaving virtually no air in the pack. Since the Flume’s seal seems to be all or nothing, I had to stand the bladder on a counter and gradually let it slump until liquid started to spill, then close the pack. Another option, which I found worked equally well with the Flume, was to turn the bladder upside-down and suck any excess air from the pack using the mouth piece. Either method worked, it’s just a matter of what you are used to.
Bladder - Open
Bladder - Closed
Hose / Bladder Attachment
Hydrapak has developed a cleaver way of connecting the bladder to the supply tube using a detachable valve system. While there are other manufacturers that offer a similar design, I like Hydrapak’s approach because it uses clear plastic which makes it easier to see if the valve is clean. The design also virtually eliminates connection related leaks since the supply tube must be properly connected to the bladder before a compression valve (found on the pack-side of the coupling) allows fluid to flow. Pouch-slump is taken care of using a plastic snap which secures the top of the bladder to the top of the pack. The bladder also has a separate hook for hanging while drying.
Valve Coupling
Nozzle Construction
Hydrapak’s nozzle design is another highlight. Other packs I have used required me to bite down on the nozzle in a very particular manner to get fluid to flow. The Flume’s nozzle, which is made from a soft silicone-like material, is far more responsive, requiring a minimal amount of force. I though this design might come at a price, but despite my best efforts, I could not make the valve leak. In one case I tried squeezing the bladder to force a leak but the valve would only allow liquid to flow when opened manually.
Nozzle View
Cleaning
Hydrapak’s top-open bladder design makes it one of the easiest hydration packs to clean. The ability to turn the pack inside out also makes it much simpler to dry - without the use of any special tools. A big plus in our view.
Bladder Turned Inside Out
