[Tested] Osprey Viper 9 Hydration Pack



Hydration packs have come a long way since their inception back in the mid 90’s.  Recently many riders have been moving away from the trend of bulky hydration packs of the last five years, in favour of a bottle on the bike and tools strapped to the frame. This is a trend heavily influenced by EWS Enduro racers. So when Osprey contacted us to test their Viper 9 hydration pack, we felt it was time to see if we would be happy with a back pack again after a few years of riding without one.

Punta Ala is an ideal place for Hydration packs, as you can be gone for three or four hours in the woods, so the extra volume is useful to carry water with you, especially if it is hot, here we can see that aside from color, the pack is pretty discrete, and has lots of functions.


  • Biostretch™ ventilated harness
  • AirScape™ backpanel with foam ridges for ventilation
  • LidLock™ bike helmet attachment
  • Reflective graphics
  • 2.5L Hydraulics™ LT Reservoir included
  • Stretch pocket on harness
  • Front zippered pocket
  • Internal hydration sleeve
  • Internal key attachment clip
  • Internal organiser for bike specific tools and spares
  • Large front compression pocket
  • LED light attachment point
  • Magnetic lockable bite valve to prevent leakage
  • Removable 20mm webbing waist strap
  • Removable webbing hip-belt
  • Side compression straps
  • Sternum strap buckle with magnet
  • Stretch mesh side pockets
  • Weight : 0.55 kg
  • Maximum dimensions : (cm) 45 (l) x 22 (w) x 18 (d)
  • Price : €90


Considering the small size of the back pack and the price, this is a fairly comprehensive set of features that this pack has been designed to cover.

The magnetic hose connector is brilliant.

The most irritating thing about hydration packs is the drinking tube and where it sits when you are not using it, Osprey have a useful magnet system and the front strap that slides on the shoulder straps so you can position the bite valve just about anywhere you want, pretty much the most useful system we have tried up until now.

Twist and bite. No leaks.

Bite valves, (normally the leaky variety) annoyed us in the past and were one of the reasons we ditched the backpack style of hydration, the Osprey did not leak once; it can be twisted on and off plus you have to bite to get it to dispense water.


Other features we liked included the second helmet strap, no irritating nets here, the “airspace” back design that lets air move, plus the really easy to access hydration compartment and tube storage zipper and the bite valve positioned out of the way if needed.

On The Back

Comfort and bulk were a reason we ditched the back packs of old, we didn’t appreciate the weight as we went around corners annoying us as the old packs shifted, Osprey have gone for a small to medium volume here that seems about ideal, there is enough space to fit all the things you need in a day, plus it’s expandable enough to fit in an extra layer should you need it.


The Viper 9 sits comfortably on our shoulders and does not move around. We found it easy to adjust and light weight, the drinking tube was easy to position and the waist strap was fairly simple to adjust, also you can remove the strap easily if you so desire, a neat feature.


At the front the chest strap can be positioned in the best place for your needs, the pack also was easy to fit around a wearable camera. The pack is easy to cinch/snug down and does not restrict your movement.

On The Bike

Every rider has his preference for bike kit comfort, we prefer to stay as low profile as possible and store what we can on the bike, the Osprey Viper 9 though is slim enough, stable enough and holds what we need for our Enduro riding zone in Punta Ala that we actually found ourselves taking it with us more than leaving it at home.

When riding with the pack the heat build up is minimal compared to packs we used in the past as the air vent does seem to work. It does not protect your back though, there are no spine boards, just a semi rigid foam support that does its job pretty well.

Using the drinking system was easy, filling up was pretty standard, we like the top fold and slide system, it is easy to open, fill up and clean. The liquid volume(2.5L) is enough for our usage over about 2-3 hours in 25 degrees. Stowing the liquid bladder in the hydration section is super easy with the wrap around zip, probably one of the easiest ones we’ve used, no passing the tube through irritating holes to set it up, very well thought out.


We  have to admit we deserted back packs a few years ago, unless we were carrying a camera we preferred the bike with bottle method. However technology and design has moved on and Osprey with their Viper 9 have addressed just about every gripe we ever had with back packs from the past.

First, it’s not too big and weighs only 550 grams.  Second, it stays in place and has just about every conceivable utilitarian function going for it, most importantly the drinking system was about as fuss free as probably can be made currently.  Then there is the price, honestly this impressed us, the ratio between material, quality, function and cost(€90) is excellent.

Overall if you have a few extra bits to carry on longer rides and you don’t like storing stuff on your frame; or even if your frame just doesn’t have enough bottle mount space then the Viper 9 seems to us a worthy contender.  If you go racing with this as well it is probably just about right : big enough for spares, but wont get in the way.

Test Center Punta Ala

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