The new Big Sky International Convertible 2P double wall tent (also available in a four-person version) introduces some new innovations to the expanding line of Big Sky tents. The Convertible is based on the Evolution's proven design and takes it a few steps further. It's called the "Convertible" because it can be configured as either a three-season or four-season tent. And it's designed so the entire tent (fly, body, footprint) can be set up as a single unit. The summer version weighs a few ounces more than the award-winning Evolution 2P, but it's tighter, better ventilated, more wind stable, and more versatile. And the winter version (Big Sky calls it "WinterLite") breaks the five-pound barrier for a two-person four-season tent. The Convertible is destined to be one of the most versatile tents around, but be prepared to make a few decisions and compromises.
The Big Sky Convertible 2P accommodates two people with two side entry doors and vestibules. The summer version weighs 3 pounds, 8 ounces with lightweight aluminum poles.
- Very lightweight for a two-person double-wall tent
- Pole sleeves on the fly create a tighter, more stable tent
- Interchangeable summer and winter interiors
- Lightweight or heavy-duty aluminum or carbon fiber poles available
- Easy setup as a single unit
- Two doors and two vestibules
- Easy side entry
- Several stake options
- Three-season or four-season configurations
- Snow flaps seal perimeter in a snowstorm
- Four large interior storage pockets
- Adequate space for two people plus gear
- Tighter, better ventilated, and more wind stable than the Evolution 2P
What's Not So Good
- No summer fly available
- Inner tent contacts the fly at the head end
- Vestibule zippers are too tight under some conditions
|2008 Big Sky International Convertible 2P|
|Three- or four-season, two-person, double-wall tent with floor|
|Fly and floor are 1.3 oz/yd2 (44 g/m2) silnylon; summer interior is no-see-um mesh; winter interior is 1.1 oz/yd2 (37 g/m2) uncoated ripstop nylon|
Poles and Stakes
|Summer version uses two carbon fiber or lightweight aluminum poles; winter version uses three heavy duty carbon fiber or aluminum poles; a minimum of six stakes are needed for a secure pitch|
|Length 84 in (213 cm), width at head end 56 in (142 cm), width at foot end 46 in (117 cm), peak height 42 in (107 cm)|
|19 x 6 in (48 x 15 cm)|
|Tent is purchased a la carte, with numerous options to choose from. Example summer configuration is 3 lb, 8 oz (1.59 kg), winter configuration is 4 lb, 10 oz (2.1 kg) (includes fly, tent body, aluminum poles, compression stuff sack, 6 stakes, stake sack)|
|Summer configuration is 3 lb, 5.8 oz (1.53 kg), winter configuration is 4 lb, 7.8 oz (2.04 kg) (excludes compression stuff sack and stake sack)|
|Floor area 32.7 ft2 (3.04 m2), vestibule area 16.8 ft2 (1.56 m2), total 49.5 ft2 (4.6 m2)|
Protected Area/Trail Weight Ratio
|14.1 ft2/lb for summer configuration; 10.6 ft2/lb for winter configuration|
|Varies with options selected; US$388 for the summer version with lightweight aluminum poles; US$515 for the winter version with heavy duty aluminum poles|
|Summer or winter body, lightweight or heavy duty aluminum or carbon fiber poles, several stake choices, guylines, storage bag, footprint|
Big Sky International's new Convertible 2P builds on the success of their award-winning Evolution 2P. Both tents have two doors and two vestibules, side entry, and the same dimensions. The poles are interchangeable between the two tents. However, the Convertible has design elements that set it apart from the Evolution and make it better in several ways.
Views of the Big Sky Convertible 2P. Each side of the tent (top left) has a zippered vestibule entry. A side view with vestibules tied open (top right) shows the tent's large doors and easy entry. The foot end view (bottom left) shows both vestibules and the tent's large top vent. A top view (bottom right) shows the tent's overall proportions.
The distinctive design elements that set the Convertible apart from the Evolution are as follows:
- The poles are inserted into sleeves on the fly, rather than sleeves on the inner tent.
- The inner tent is attached to the fly with mini quick-release fasteners.
- A third pole can be added for increased stability in snow and wind.
- A large top cap vent provides improved ventilation.
- Snow flaps around the perimeter of the fly help secure the tent in a snowstorm and prevent snow from coming inside.
Distinctive design elements of the Convertible. The foot end view (left) showing the tent's large top vent, pole sleeves on the fly, and third pole attached to add stability and extend the vestibules. The snow flaps are rolled up in the photo. Two interchangeable inner tent bodies (mesh or breathable nylon) connect to fasteners on the fly (right).
Purchasing a Big Sky tent is like ordering a la carte in a restaurant - it allows you to get exactly what you want, but you need to make a decision on each component rather than order a pre-selected package. It helps to know what you want, and perhaps this review will help in that regard.
By choosing the appropriate components, the Convertible 2P can be configured as a lightweight three-season tent or a sturdier lightweight four-season tent. Big Sky qualifies the latter as "WinterLite," meaning it's "suitable for camping in snow and cold weather, and capable of withstanding moderate wind and snow loads. Please note that this shelter is not 'Mountain,' 'Alpine,' or 'Expedition' rated and is NOT intended for use in extreme weather conditions." With their WinterLite rating, Big Sky has basically created a new tent category (as defined above) for travelers who want to do an occasional short duration winter camping trip under better weather conditions.
There is only one fly available (with snow flaps), so both summer and winter configurations use the same fly (more on that later).
The three-season configuration typically uses two lightweight poles (aluminum or carbon fiber) in an X-pattern and a mesh interior (left). The summer interior (center) is all mesh (except for the silnylon floor), and there is no access to the top vent from inside. The fly can be pitched by itself (right) using an optional X-cord that clips to the pole ends.
The four-season configuration typically uses three heavy-duty poles (aluminum or carbon fiber) and a breathable nylon interior. The third pole (left) adds stability to the tent and extends the vestibules. Opening the snow flaps (center) around the perimeter anchors the tent and keeps snow from entering around the sides. The winter interior has zippered openings in the ceiling (right) for increased ventilation and access to the top vent from inside.
Although I present typical summer and winter configurations in the above photos, the beauty of the Big Sky a la carte system is that the user can select the components that best meet his/her needs, budget, and conditions (more on that later).
Inside features. Both interiors have large mesh pockets at the head (top left) and foot (top right) ends. Each side vestibule (bottom left) is 8.4 square feet, which is not huge, but adequate for equipment storage and cooking (with good ventilation). Floor area (bottom right) is adequate for two sleepers. The large entry doors tie open out of the way to incorporate the vestibules into the usable space inside the tent.
I field tested the Convertible 2P a bit backwards because I obtained the fly, summer interior, and three heavy-duty aluminum poles at first, and used that configuration for winter camping, then later obtained the winter interior (when it became available) and used it for spring and summer camping. Overall, it was fortuitous because I experienced the pros and cons of using both interiors in winter and summer conditions.
Setup is easy and fast. As I mentioned, the interior and fly (and optional footprint) can remain attached and the entire tent can be set up as a single unit. Simply thread two long poles into the pole sleeves on the fly until they reach dead-end pockets at the other end, then slip the tips into grommets on the rear corners of the tent. Six stakes are required (four corners and two vestibules) for a secure pitch, and four optional guylines can be attached for extra wind stability.
Big Sky's new Y-Not stakes (left-left) are 5 in long, weigh 0.4 oz each, and hold much better than titanium hook stakes. Their new SnoAnchor stakes (left-right) for winter snow camping weigh just 1 oz each. Big Sky's new ShelterSaver groundsheet (right) is made of type 1443 "soft structure" Tyvek, the same "fabric" that is used in disposable Tyvek clothing. It's very durable, lightweight, and functionally waterproof. The ShelterSaver adds 4.4 oz to the weight of the tent and can be left attached.
My first trips using the Convertible 2P were winter snow camping outings by myself or with my wife. On my first trip I camped on a ten-foot snowpack at 11,800 feet. After a few hours of delightful backcountry skiing in the area, it began to snow and blow, and I retreated to the tent. I refuged from late afternoon though the night solo in the comfort of the Convertible, observing how the tent performed during the course of a six-inch snowfall driven by twenty mph winds. It performed remarkably well. Snow accumulated on the extended snow flaps around the perimeter to help anchor the tent in the wind and prevent snow from entering around the sides of the tent. The mesh summer interior basically worked well, except some spindrift entered through the top vent and filtered down through the mesh, even with the vent closed with a Velcro tab. Obviously the winter interior would have worked better, because the nylon would have shed the spindrift. Under those windy conditions, I had no problems with condensation inside the tent.
The morning after a 6-inch snowfall at 11,800 feet. The Convertible didn't budge in a 20 mph wind.
Three other winter trips were under calmer conditions, with lows down to 16 °F. Under those conditions, we rolled up the snow skirt and mesh doors for more ventilation, but the clear/calm/cold conditions resulted in a lot of frost on the inside of the fly, especially on the vestibules. Again, the summer mesh interior worked well, but the winter nylon interior would have been warmer.
In the spring, we took the Convertible on two rafting trips for a total of thirteen days, using the summer mesh interior for better ventilation and three poles for extra wind stability. On two very rainy nights, with the mesh doors open, I had copious amounts of condensation on the inside of the tent fly, especially the vestibules. The mesh interior separated us from the wet fly, but we had to be careful not to brush against the inside of the wet vestibules. Under such cool/calm/rainy conditions, heavy condensation is inevitable in any shelter.
On a 40 °F rainy/calm night (left) we had copious condensation on the inside of the tent fly. The air temperature hit the dew point temperature (right) most of the night. In this scenario condensation is inevitable in any shelter.
My photos and graphs showing condensation in this double-wall tent depict the extreme conditions where condensation is inevitable in any tent. In fair weather, especially with the vestibules open at night, we had no condensation at all. Overall, the Convertible has adequate flow-through ventilation and is not especially prone to condensation.
In early summer, the winter nylon interior finally arrived and we tested it on a high elevation backpacking trip, where there were still lots of snowdrifts around and nighttime temperatures dropped below freezing. On our first night, we tied the interior doors open and closed the vestibules, and there was light frost on the inside of the vestibules in the morning. The temperatures inside and outside the tent were about the same. Under nearly identical weather conditions the second night, we closed the interior doors and vestibules. The morning temperature inside was about ten degrees warmer inside, and we had heavy frost on the inside of the tent fly.
Because it's designed to be versatile, the Big Sky Convertible can be difficult to understand, and choosing the desired components using Big Sky's a la carte system can be a bit challenging. However, it needn't be that confusing. Many buyers simply want a three-season tent, so the summer configuration with a mesh interior and lightweight aluminum (or carbon fiber) poles will suffice. Other buyers may prefer a nylon interior, or may plan to use the tent year-round, so they may wish to purchase both interiors and different pole and stake sets. Still other users may want to use three heavy duty aluminum poles for extra wind stability. And the fly-only configuration (with or without a footprint) provides a very stable single-wall shelter. The versatility introduces some complexity, but it's worth it in order to get what you want.
Overall, I found the Convertible 2P to be a well designed, highly versatile, and stable tent. It introduces some new design elements into the Big Sky line of lightweight tents. However, pole sleeves on the fly and clipped-in interior is not a brand new concept. I reviewed a Vaude tunnel tent a few years ago that used the same concept, but Big Sky's iteration goes one step further by allowing the user to easily switch between a mesh or nylon interior and use different pole and stake sets. I found that the design works, and I had no problem erecting the tent as one unit repeatedly in the field. In my opinion, we will be seeing more tents using this design approach in the future.
With the summer mesh interior and two lightweight aluminum poles, the Convertible 2P is just 2.6 ounces heavier than a similarly configured Evolution 2P. I would personally choose the Convertible over the Evolution because it pitches tighter, has better top ventilation, and is more wind stable. It's also more versatile, if the user wants one tent that will serve multiple needs.
The downside is the snow flaps on the fly - only one fly is available, and it has the snow flaps. For fair weather camping, when more ventilation is desired, the snow flaps can be rolled up. However, even when they are rolled up, they are not completely out of the way, and give the tent a disheveled appearance. But that's the compromise when purchasing one tent to serve multiple purposes. Another issue is the vestibule zippers can be very tight at times. Nylon stretches when damp and shrinks when it dries. I encountered several occasions when closing the zippers put a lot of stress on them, and I had to reposition stakes or pull on one side to avoid blowing out the zipper.
The main issue I have with the Convertible 2P is the lack of a summer fly. Only one fly is available, and that is basically a winter fly with snow flaps. Toggles and loops are provided so the snow flaps can be rolled up when they are not needed, but as the photo shows, the snow flaps are extra clutter when summer camping. Big Sky contends that the snow flaps can be cut off if they are not wanted. Bottom line, the snow flaps are a compromise when the tent will be used for both three- and four-season conditions.
There are no close comparisons to the Convertible in terms of design and weight. Big Sky tents are simply the lightest double wall tents available on the market. The REI Quarter Dome T2 weighs four pounds, two ounces and has less floor and vestibule area, but it is bargain priced at US$259. The Montbell Thunder Dome 2 weighs just over four pounds, has slightly less floor area, only one entrance and vestibule, and costs US$299. These tents are better compared to the Big Sky Evolution 2P, which weighs a pound less.
The Convertible is the most versatile double wall tent available, with multiple interior, pole, and stake combinations available to create different three- or four-season configurations. The entire tent can be quickly set up as a single unit.
Recommendations for Improvement
- Redesign the snow flaps on the fly so they are completely out of the way for summer use, or offer a summer fly without snow flaps.