Ultralight Bivi Bag / Sleeping Bag Cover
Bivi bags are not the preserve of scummy alpinists or even those of a more tactical nature. They can add a useful layer of protection for almost any user, particularly if you intend to sleep out in damp conditions that will put even the most expensive down sleeping bag to the test. There is now also an XL version available.
We had two constraints; firstly minimize the amount of fabric to keep weight and price low, and secondly we should be able to fit a winter sleeping bag inside without squashing the down. We have spent a great deal of time resolving these issues to produce an efficient pattern with little waste, whilst still designing a bivvy bag that works. A simple, affordable but properly waterproof / breathable bivi cover weighing 400g. We hope you like it.
Current Gore-Tex/eVent air permeable bivvy fabric has a moisture vapour transmission rate (MVTR) of 25,000. As a comparison old Taslan Gore-Tex weighed in at around 15,000 and our fabric is about 10,000. In real terms this means that if you are not breathing into it, then it is breathable enough. In some conditions you will get condensation on the inside of the fabric but for most people this seems to be manageable.
The Hunka XL is designed to accommodate the larger frame, a puffy winter bag or simply to give yourself more room in which to move around. If you have a larger sleeping bag then the Hunka XL will help ensure that the down baffles are not compressed against the side walls and your valuable insulation is not compromised.
|Model||Weight (gr)||RRP (£)||Fabric|
|Alpkit Hunka||388||30||PU coated Nylon|
|Macpac Alpine Cocoon||780||200||eVent|
|Mountain Equipment Ion Bivi||280||90||DriLite|
|Rab Storm Bivi||560||60||Hyperlite storm|
|Terra Nova Discovery Lite Bivy Bag||450||170||Gore-Tex Flo2|
|Rab Survival Zone||320||60||Pertex Shield|
|Blizzard Survival Bag||385||30||Reflexcell|
|Phd Delta Bivvy Bag||410||134||DriShell|
|BD Winter Bivi||280||130||Epic|