The Integral Designs Wedge eVENT bivy in Washington’s Cascades.
The Integral Designs Wedge eVENT Bivy is more like a short tent than a traditional bivy. With a two-crossed-pole "wedge" design, it is similar to other single-wall tents except for its very low profile – it is only twenty-four inches tall. This height clearly classifies it as a bivy and not a tent. However, it is generously sized in length and width for even a tall solo hiker, with space for gear inside the tent. Made of extremely breathable eVENT and with solid wind stability, it’s a shelter that can handle the most unforgiving weather and alpine environments. At just over three pounds, the Wedge Bivy is a shelter that can make it through the harshest environments. An optional vestibule adds a great deal of storage and living space, adding versatility.
The Integral Designs Wedge Bivy is a unique shelter. It’s short, but sized for comfortable sleeping – even for a tall person. It’s built out of eVENT, which is unparalleled for breathability and condensation resistance while remaining completely storm-worthy. The optional vestibule provides generous space for gear or cooking and can be dug out in the snow for extra foot space. It’s just over three pounds (without vestibule) which is very light for a bomber solo tent, but quite heavy compared to a full-featured bivy such as the two-pound Integral Designs EXP Unishelter Bivy. The Wedge Bivy is beyond a traditional bivy, though, and this is where the Wedge lives – right between a full-featured bivy sack and a bomber solo tent.
The Integral Designs Wedge Bivy has some similarities to the Rab Summit Extreme (now called the Rab Superlite Bivi which is a bit longer, shorter, and lighter). Like the Rab tent/bivy, the Wedge is made of single wall eVENT, sized for a solo hiker, designed to handle extreme conditions, and has a very low ceiling height (the Wedge is 24 inches tall, the Rab Summit Extreme was 33.7 inches, and the Rab Superlite Bivi is 27.5 inches). While the Integral Designs shelter doesn’t have the direct harness tie-outs that make the Rab tent unbeatable for extreme alpine-style ascents, it has some unique features such as an optional vestibule, an easy to use entrance, and nearly vertical walls at the head and foot that give it an edge in versatility.
A top view of the Wedge with the eVENT (left) and mesh (right) doors in use. Note the sky views that are available when using the mesh door.
The pre-bent Easton aluminum poles create almost vertical walls at the ends, and the large doorway cutout makes entry and exit much easier.
The Wedge bivy has a traditional “wedge” design with crossing aluminum poles. This is a common design for one- to two-person four-season shelters, due to the combination of wind stability, snow load capacity, and relative light weight. However, the asymmetrical pre-bent Easton poles provide more vertical walls at the head and foot of the shelter, increasing usable space. Straight arched poles limit the interior space of a shelter this short, due to the tight angles at either end of the tent, but the Wedge Bivy design eliminates this issue.
The doorway is another unique design element. It is cut far back into the top of the tent, making entering and exiting the Wedge very easy. The door also allows views of the sky on clear nights. On clear but buggy nights, the mesh door offers full views and an open-air feel. The downside of the large door is that rain comes straight into the living area when the door is open, although the optional vestibule eliminates this issue.
The crossed-pole design and pre-bent poles make an efficient, but very low living space.
The Wedge Bivy offers comfortable space for sleeping (left), but my knees could easily touch the ceiling (right).
At only twenty-four inches high at the peak, the Wedge Bivy is a very low shelter. In fact, it is so low that my knees touch the ceiling when slightly bent while using a three-inch down air pad. Turning around while inside the tent requires advanced flexibility – don’t expect to easily get items at the foot end of the shelter, and you can forget trying to sit up. However, the sleeping space in the Integral Designs shelter is quite comfortable. I’m 6 feet 2 inches and had length to spare. With twenty-one square feet of space, there was room for gear storage, even when using a winter bag. I found the shelter to be far less claustrophobic than a traditional bivy sack. It might be possible for two people to survive a night in the Wedge Bivy, but I would save this only for emergencies or ultralight summit attempts. Used in this setting, though, the Wedge would be great for keeping two climbers warm, dry, and safe.
The poles attach with a three-piece Velcro attachment for extra security. Pole pockets in the rear (bottom right) make a secure placement in the cramped rear end easy.
The Wedge Bivy is pitched with interior poles. After extending the poles, you slide the them into pole pockets at the rear of the tent, ensuring that the tips will be in the correct position. This is a great addition, especially with this shelter’s tight quarters. After placing the front pole tips in position, Velcro tabs are attached to hold the poles in place. The three-piece Velcro tabs provide extra strength over other systems I’ve used and are easy to attach.
There are two pockets inside the Wedge: a usable one in front (left) and one in the back that was very hard to access (right).
Two interior pockets provide small item storage. I found the front one to be very useful, but the rear one was extremely difficult to access unless I crawled in head-first. I think it would have been better to have two pockets at the head end of the shelter. The rear pocket may have been intended for a second sleeper, but regular use for two people seems like a long shot.
In continuous rain and sub-zero conditions alike, the eVENT fabric kept the interior dry and condensation-free. Only the silnylon vestibule had condensation (right).
As stated in the Backpacking Light article The eVENT Single Wall Tent: Here, Then Gone – What’s Replacing It??, tents made of eVENT are extremely rare. This shelter can be made from the fabric because it falls into the class of “bivy shelter” due to its low height. The use of eVENT is a serious bonus; it is amazingly breathable while remaining completely waterproof. Like the Rab Summit Extreme, I was stunned by the breathability of this shelter. In the field, I experienced almost no condensation in above freezing conditions and very little frost build-up in sub-freezing conditions.
In the past, I tested the breathability of the Rab Summit Extreme eVENT tent by boiling water in the sealed tent for several sessions of ten to fifteen minutes. When finished, I collected condensation with a paper towel to weigh the total condensation. Each time, I was only able to detect moisture on the aluminum poles and on the seam tape – total condensation only measured 0.1 oz after a fifteen-minute boil. I simply could not make condensation occur in these conditions. Similar tests in the field yielded similar results with the Wedge Bivy – it has amazing condensation resistance.
Given the right conditions, condensation will occur with any tent. However, I have found condensation extremely difficult to find under any conditions in eVENT shelters. I still hold the opinion that eVENT is a magic fabric when used in a single-wall shelter.
When comparing condensation between the eVENT bivy and the silnylon vestibule, the difference between the fabrics was obvious, with significantly more condensation in the vestibule. Where the two fabrics overlap, there was more condensation inside the shelter when using the vestibule, but it was minor and in a relatively small area.
The closable vent allowed further ventilation, although it seemed to be largely unnecessary due to the eVENT fabric.
Besides the highly breathable eVENT fabric, the Wedge Bivy also includes a closable tube vent on the door with a mesh backing. This vent adds to the shelter’s ventilation and also serves as a small window to check outside conditions. On most nights I slept with the vent closed and with minimal condensation, raising the question of whether this feature is necessary in an eVENT shelter. However, it would be a welcome addition during warm summer rains when opening the door is impossible.
On each side there are three guy-outs and three high stakeout points, which I used as adjustable triangulated guy outs. Two additional guy-outs on the top of the tent makes fourteen guy out points total.
There are a grand total of fourteen stake and guy-out points on the Integral Designs shelter. I added plastic sliders to the guylines for easy adjustment and found that when using twelve of the points, the bivy was virtually unmoved in moderately high winds. With its low profile design and guy-outs that are reinforced with interior attachments at the Easton poles, I would feel confident bringing this bivy into the scariest storms. Two additional guy-outs at the top of the tent add even more confidence.
The optional vestibule adds a great deal of living and storage space. It uses a single pole, has a side entry (bottom left), and attaches with a plastic buckle (top right) and lower pole grommets. It fits a large pack (bottom right) and has enough space for cooking.
An option vestibule adds $85 and 12.4 ounces to the Wedge Bivy. The vestibule is constructed of silnylon for lighter weight and uses a single Easton aluminum pole to increase the space. It attaches quickly to the shelter with a snap buckle, a grommet on either side, and a single stake in front. The vestibule is taller than the actual bivy, making it a comfortable place to sit up, organize gear, and cook, especially when digging it out in the snow. It has a side entrance that rolls up, giving a generous entrance while providing full rain coverage over the shelter door.
The vestibule adds a great deal of versatility to the shelter and makes it much easier to live with in conditions where you’re trapped inside for extended periods. It doesn’t have the extreme wind stability of the bivy (or the guy-out points) but in moderate conditions, it held up just fine. On one night when the winds picked up and the vestibule started to shake, I was able to pull my gear inside the bivy and quickly take down the vestibule to stash it inside. I found the combination of extra living space with the backup of a bomber solo shelter to be a great combination for a variety of conditions.
The doors roll up with simple ties that are hard to manage in gloves and cold hands.
A few details were missing on the Wedge Bivy. The included guylines lacked plastic adjustors, the four included stakes were only sufficient for the most basic pitch, and the doors included simple ties that were hard to manage with cold hands. I would have appreciated extra stakes and a full guyline kit as I’ve seen from other manufacturers. Rolled door closures made of bungee material or using toggles are much simpler to use in cold conditions and would be a welcomed change.
At $400 the Integral Designs Wedge Bivy ($485 with the vestibule) is not an inexpensive shelter. However, it is a good value when compared to bomber single-wall tents. The construction is superb, and it is sure to last many seasons. The eVENT fabric is extremely rare in a tent and will keep you dry on even the most humid nights. Most importantly, you are sure to survive storms that would destroy lesser shelters. If a bomber bivy suits your needs, the Wedge Bivy is hard to beat.
Scour the market and you’ll see just how rare and unique this shelter is. eVENT is a magic fabric that’s only available if you’re willing to accept a low ceiling height (and this is certainly a low ceiling height!). But for those that want a bomber shelter that’s a bit more than a bivy, not quite a full tent, but has the versatility of an optional full vestibule, the Wedge Bivy will suit your needs perfectly.
|Year/Manufacturer/Model||2010 Integral Designs Wedge eVENT Bivy|
|Style||Four-season, single-wall, freestanding floored shelter with optional vestibule|
|Included||Shelter body, two pre-curved Easton aluminum poles, four Easton stakes, four ten-foot guylines, stuff sack, stake bag|
|Fabrics||Body: Direct Venting eVENT Fabric
Floor: 1.9-oz taffeta nylon floor fabric with a 0.5-oz urethane coating
Interior Mesh: 0.7-ounce no-see-um netting
|Poles and Stakes||Two Easton 0.340 in (8.6 mm) 7075-T9 aluminum poles, four Easton aluminum tubular 6.5 in (16.5 cm) stakes|
|Dimensions||Floor Length: 88 in (220 cm)
Floor Width: Front – 45 in (112 cm), Rear – 31 in (77 cm)
Peak Height: 24 in (60 cm)
|Packed Size||19 x 5 in (48 x 13 cm)|
|Total Weight (includes tent, included guylines, stuff sacks, poles, stakes)||3 lb 3.5 oz (1.46 kg)
Manufacturer specification: 2 lb 15.2 oz (1.34 kg)
|Trail Weight (includes tent and stakes, excludes guylines and stuff sacks)||3 lb 0.9 oz (1.39 kg)|
|Protected Area||Floor area 21.0 ft2 (1.95 m2)|
|Protected Area/Trail Weight Ratio||7.0 ft2/lb|
|MSRP||$400 USD, available in yellow or green|
|Optional Vestibule||$85 – includes 30d 1.1 oz silnylon grey vestibule, one Easton aluminum pole, silnylon stuff sack; adds 7.0 ft2 (0.65 m2) of space; 12.4 oz (351 g) including .4-oz (10-g) stuff sack|
- Lightweight, at just over three pounds, for a solo bomber shelter
- eVENT is extremely breathable, and extremely rare in traditional tents
- Long enough for a tall hiker and enough space for some gear inside
- Low wind profile with fourteen guy-out points for fantastic wind stability
- Optional vestibule adds a great deal of versatility for just over twelve ounces
- Large front entry with mesh door that offers sky views
What’s Not So Good
- Extremely short at only twenty-four inches – not tall enough to sit up
- Heavy for a bivy (but light for a tent)
- Open door lets in rain and snow, making the vestibule necessary in poor weather
- Expensive at $400 (or $485 with the vestibule)
- Guyline adjustors aren’t included and only includes four stakes
Recommendations for Improvement
- Include enough stakes for a full pitch and plastic adjustors for the included guylines
- Move the rear pocket to the front where it can be more easily accessed
- Trade the ties for door roll-ups with elastic toggles or plastic adjustors to make them easier to use
- Consider making a taller version of the Wedge – the bent poles would be a great addition to a larger shelter as well
Disclosure: The manufacturer provided this product to the author and/or Backpacking Light at no charge, and it is owned by the author/BPL. The author/Backpacking Light has no obligation to review this product to the manufacturer under the terms of this agreement.