Just In - Osprey Manta 25

Just in for review is a very early sample of Osprey's new Manta 25 hydration pack which uses the company's interesting new 'Hydraulics' hydration system that we reported on a week or two back.


You won't be able to buy a Manta or its biking cousing, the Raptor, until early 2010 and the sample we have still has some minor faults, but we thought you'd like a quick look at how the hydration gubbinis work in practice and an overview of the pack itself. We'll give you a full run down once we've used it in anger.



The heart of the Hydraulics system is the Hydroform Reservoir, which is made for Osprey by Nalgene. It has two obvious stand-out points. The first is a flat, foam back which makes the whole bladder rigid and free standing and is intended to prevent barreling when the bladder and pack are full.


The other is an integral handle which is supposed to make it easy to hold the bladder with one hand when filling from a tap leaving the other hand free to control water flow, bat mosquitos or eat chocolate...

And the good news is that both features seem to do exactly that, though the production pack will have a more rigid handle.

The next claim is that the bladder will still slide easily into its compartment in the pack, even when it's fully loaded. And the good news is that that's exactly what happened, which should make mid-trip refills a much more convenient business than the classic 'empty the sac' scenario we're used to.


Once the bladder's fully home, you zip up the hydration compartment top and then, here's the clever bit, fasten two top straps and cinch them down. The idea is that the contents of the bladder are now under pressure making for a much easier water supply to the bite valve. Interesting...


So, does the pressurised feed work. The answer, based on a quick squeeze on the bite valve, seems to be yes, the water is squirted out under some pressure, no heavy sucking needed. We're still not 100 per-cent convinced that this is a necessary feature, with a decent bite valve like Camelbak's, we've never had issues with flow rates. That said, the Nalgene valve based on past experience, isn't in the same class, so maybe some hydraulic assistance does make sense.


One concern we do have is that any leakage in a worn bite valve is going to be more obvious thanks to the pressurised system. That said, most fully-loaded hydration packs do pressurise their contents to some extent anyway, just not deliberately.

As for the pack itself, it's a classic Osprey day sac complete with a ventilated Airscape back system,  Stow-on-the-Go pole holders, a variety of stretchy stowage pockets and simple but effective compression straps. Shoulder straps use perforated foam and neat hip-belt pockets provide easy access storage for small things.


At 25-litres, it's large enough to cope with a summer day load and maybe even a winter one if you travel light. And it has that unmistakeable Osprey feel and look too.

We'll bring you a full assessment once we've had a chance to use the Manta 25 properly, but first impressions are that Osprey has done some interesting things with the hydration side of it.

More about Osprey packs at www.ospreypacks.com