If you've always secretly dreamed of converting an old Coca Cola
bottle into a fully-fcuntional hydration system, then this is your
lucky day thanks to the new HiGear SmarTube.
Essentially
it's a hydration tube and bite valve that comes with two bottle caps
that should allow it to screw directly onto most commonly available
plastic drink bottles. There will also, apparently, be a Sigg bottle
adaptor available shortly which will allow you to use the same tube
with your Sigg water borttle.
The clever bit is that the kit incorporates a one-way valve that
sits in the bottle cap and sucks in air as you breathe. Without it a
vaccuum would form in the bottle and make it harder and harder to
extract any water at all. So does it work?
We grabbed an old Diet Coke bottle, fed the contents to a passing
dog and screwed the tube and cap into place after filling with water.
First suck and success, water comes out of the blue bite valve.
Unfortunately in standard trim, the bite valve is pretty low flow, a
bit like trying to suck up a millkshake through a very narrow
straw.
We confirmed this by substituting a Camelbak valve, which gave a
massively better flow and allowed the SmarTube to work as intended -
without it, it's simply hard work. A semi-solution was to use a sharp
knife to enlarge the slit in the standard valve to allow a higher
volume flow. Unfortunately, a trade-off from this was to allow water
to leak from the valve if the slightest pressure was applied to the
bottle, as would happen when carried in a loaded pack.
In
standard trim then, we reckon the SmarTube is let down by the flow of
its bite valve and modding it to allow it to work properly spoiled
the seal. You could simply fit a Camelbak bite valve - the best on
the market in our experience - but that would set you back another
fiver and you could buy a 1.5 litre Camelbak Omega reservoir for only
£19 including valve.
