USWE Flow 16 hydration backpack: harness the power

Clever X-shaped shoulder straps secure this well-thought-out bag and eliminate bounce.

USWE Flow 16 hydration backpack with helmet

by Adam Binnie |
Updated on

The USWE Flow 16 hydration backpack is an upgrade on the tactical hip packI spoke about in my Topeak Mini PT30 multitool review, which I use on my mountain bike in order to combat the dreaded pre-ride faff.

The idea was I could leave a small pack filled with all the tools I’d need in my garage, ready to clip around my waist at a moment’s notice when the opportunity for a ride presented itself. For a while this was fine – and still is for rides where I don’t stray too far from the car (read: bike parks) because I have a bottle cage on my frame and can sustain myself well enough with that.

Related: Best cycling backpacks

However, increasingly this setup is inadequate for family rides (where I need to bring an inexplicably large number of extra items) or longer trails where one single bottle of water was not enough. I’m also getting to an age where falling off really hurts and in the interest of being able to pay my mortgage on a Monday, following a huge off on Sunday, I should really invest in a back protector.

The answer, of course, is a rucksack. I own several, but the noise from my tools rattling around and the way they bounce around on my back were the reasons I binned them off for a waist pack in the first place. However, USWE’s parachute-pack-aping rucksacks caught my interest, and this Flow 16 promises to be the answer to all my problems. Read on to find out if it is.

User Unisex
Harness NDM 2.0 + Snug-Me
Chest size 43-55cm / 17-22”
Pack weight 1210g (*excl. protector)
Dimensions 50L / 25W / 18D (CM)
Volume 16L
Hydration capacity 3,0L / 100 oz (Not Included)
Other features Helmet carry system, Rain cover, LED-Light attachment points, reflective stips
Pros Cons
• Very secure • Not cheap
• Back protection • A little heavy
• Waterproof (cover) • Hydration pack not included

Verdict: Not cheap by any means, but it ticks all the boxes for me, and the price is easier to justify when you consider the Flow 16 does the job of several rucksacks in one – toolbag, hydration pack and back protector. Plus, it has a waterproof cover and sits firmly on your back without moving around. Consider it an investment in your hobby and it’ll do everything you need, really.

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USWE Flow 16 hydration backpack buckle
©Adam Binnie/What's The Best

• Easy to adjust for a good fit

• Lots of pockets to stash things

• External webbing for helmet or pads

USWE’s clever straps and waist support belt combine to form a harness (called No Dancing Monkey 2.0 in this latest generation) that holds you tightly, in a high position on your back that stops it bouncing around.

Elastic webbing attaches to the bottom of the harness and runs through a metal tag on the bag, and then does up around your middle with a buckle. All of this can be tightened or loosened to get the fit you want, and the bag is pretty secure with the waist strap left undone, although this is less comfortable if you store things in the hip pockets.

These are a nice addition and handy for items like energy gels or snacks that you want to reach quickly without having to take the bag itself off your shoulders. But they’re too small for my big phone (Galaxy Note), and the only way to fix this is to buy an additional external pocket that attaches to the shoulder strap.

To be honest, this might not be a problem if you have a normal-sized device, and really one of the nice things about getting out and about is also getting away from your phone. But it’s worth considering if regularly stopping for a quick picture of the scenery, trail selfie, jumpline Instabanger, etc is important to you. You know who you are.

The buckle in front of your chest draws the harness together in an X shape that helps reduce lateral movement and undoes by pressing a big circular tab in the middle. This can be done easily with or without gloves.

Finally, the surface that presses into your back (and the shoulder/hip straps themselves) have a perforated design to help increase airflow and stop you from getting hot on longer rides. I’ve only worn it in cold weather but even so, it feels more breathable than my old bag.


USWE Flow 16 hydration backpack main compartment
©Photo: USWE

• Space for all your stuff

• Secondary pocket has lots of sections

• No bladder included

There are two main pockets - the big one also houses a hydration pack (not included) and CE-certified back protector (included) which work well together, the latter giving the backpack support and shape even when the bladder is only half full. There’s also a soft pocket up top for things like glasses or your phone.

Although sold as a hydration pack, the Flow 16 doesn’t come with a bladder (this isn’t hugely unusual these days, in fairness, and you could just find a cheap 3-litre one to slot in there) but the proper USWE bladder is really good, with a clever plug and play hose system that makes taking it out much easier.

That said, this main section is obviously more useful if you go riding without a hydration pack (or only put one litre in it) and I’ve found a good solution when I’ve got a lot to carry is to put a bottle on my bike and carry a spare in the Flow 16. The 3-litre bladder really does take up a lot of room when full, and you can carry lots more stuff without it.

The second section has all sorts of smaller pockets in it to secure individual items. I keep things like a pump, CO2 cartridges, puncture kits and anti-mist goggle spray in there, for example. On the outside is a stretchy pocket of sorts that can be used to stash a helmet or knee pads, and there’s a waterproof cover, too.

There are white straps you can use to compress everything down to keep the profile small and the centre of gravity close to your body, this is particularly useful for reducing movement when you’ve got a hydration pack in there. Finally, LED-light attachment points and reflective material help make you more visible at night-time.


USWE Flow 16 hydration backpack straps
©Photo: USWE

• Stays put on your back

• Less effective when crammed full on rough terrain

• Really comfy regardless

All of that is great, but what matters is whether it does what it says and stays welded to your back on a bumpy ride. Well, I’ve been out several times now over varied terrain (and some jumps) with various amounts of kit packed away in this bag so I can answer that question with some authority - yes, it does.

You have to cram it full of stuff and send yourself down some serious hills before the Flow 16 moves even a little bit - it is genuinely really impressive how well it hangs on.

As a comparison, I’ve also got a smaller USWE Airbourne 9 bag and the Flow is almost as impressive, despite being quite a bit larger - in reality, the Airbourne is big enough only for a 3-litre bladder and a few tools. I suspect if you could get as much stuff into the Airbourne as the Flow, it’d move the same amount.

For all but the most extreme terrain then it’s really comfy, and the fact it sits a little higher up your back means less fatigue on a long ride. Even on very bumpy ground, it’s a world apart from strapping some old school bag to your back and then being pummelled by it over every root and rock.

Your rucksack moving around on your back isn't just annoying, it's dangerous too. Not only can a shifting bag throw your centre of gravity off (not ideal mid-air) but a loose strap can slip off your shoulder and restrict your arm movement. Also it's just distracting and annoying having to shift it back into the right spot all the time.

Thankfully, I can’t say whether the back protector is effective or not as I’ve not crashed with it yet, but It certainly flexes nicely and feels like it covers a large section of my spine.


The best way to describe the price of the USWE Flow 16 is "not cheap". The RRP is £179, although you can find it on sale at the moment for £125, plus another £25 for the USWE hydration pack.

I reckon both are worth it – the bag feels constructed to last and given the abuse mountain bike kit gets, you want something sturdy. I reckon I'll last for years and years.

Cheaper water bladders aren’t really that much cheaper, and the USWE one is really nicely constructed with some clever features like a plug and play hose and a slide-top filling system that allows you to turn it inside out to dry.


I was looking for a single rucksack suitable for longer solo rides and family days out that I could leave packed with tools, to replace the three I used to have to swap between because they all did different things. It needed to be waterproof (or have a rain cover) and feature a hydration pack and back protector. Finally, it would need to sit comfortably on my back and not bounce around over rough terrain.

The USWE Flow 16 does all of these things and more, and is so useful and comfortable it’s now my go-to for most rides, even ones where I’d previously have just used a hip pack. It doesn’t come with a hydration bladder as standard, so budget extra for this additionally useful item and you’ve got yourself the perfect bike ride daypack.

Score: 4/5

Pros Cons
• Very secure • Not cheap
• Back protection • A little heavy
• Waterproof (cover) • Hydration pack not included

How we tested it

I took the Flow 16 hydration backpack on family rides (country paths, blue-graded singletrack) and some more challenging solo trips (local bike park, black-graded trails, big jumps) and tried carrying a variety of different items. These included a 3-litre water bladder, several changes of clothes for my kids, extra water bottles, tools and even my SLR camera.

Adam Binnie is the Commercial Content Editor and reviewer for WhatsTheBest, specialising in bikes, fitness, cars, parenting and cooking.

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