Yama Mountain Gear is an ultralight shelter and gear maker that makes backpacking gear using cuben fiber and silnylon. Owned by long distance hiker and unicycler, Gen Shimizu, the company has quickly established a fiercely loyal following with long distance hikers for its innovative shelter design and impeccable product quality.
I purchased a sinylon version of Yama Mountain Gear’s Cirriform DW-1P Tarp Shelter for a 250 mile section hike on the Northern Virginia Appalachian Trail that I just got back from and I couldn’t be more pleased with the design and performance of the shelter. If you are looking for an easy-to-pitch double walled tarp shelter with excellent ventilation and a large front vestibule for storing gear in wet weather, check out the Cirriform DW-1P or YMG’s other innovative tarp-tent shelters.
Three-Panel Front Vestibule
The Cirriform DW-1P has a unique three-panel front vestibule design that provides more interior volume and venting options than tarp shelters with two-panel vestibules. This is handy in wet weather and improves the livability of the shelter since your head is positioned at the vestibule end.
Each of the panels can be rolled open independently, so you can easily moderate how much front ventilation, privacy, and covered storage space you want, or you can roll open of the panels at once in order to pitch the tent as an open-ended A-frame (see top photo). There’s also a top vent in the middle panel to help vent moisture during rain storms or when the front vestibule is fully shut. The only possible downside of this design is that there is an extra seam to seal in the vestibule if you buy the silnylon version.
The vestibule zips open on the right hand side of the vestibule (viewed from inside the shelter) using a waterproof zipper, reinforced at the bottom with a plastic clip.
Double-walled vs Single Wall Shelters
Yama Mountain Gear makes a double-walled and single walled version of the Cirriform. I purchased the double-walled version because I knew I wanted to use the inner tent as a bug and mouse bivy on those nights when I sleep in a shelter rather than pitching a tarp outside. I also have a preference for double-walled shelters because it’s possible to pitch the outer fly first in heavy rain, before hanging the inner tent inside to keep it as dry as possible, or to leave the inner tent at home when it’s not needed for bug protection.
The standalone inner tent for the Cirriform DW-1P is quite spacious, with solid 8 inch side walls, to prevent rain splatter from bouncing under the outer fly into the inner tent’s living space. The inner tent also has mesh venting at its foot end to enable moisture venting at night. Rain splatter is a big issue with any tarp shelter like this and having high solid side walls (with mesh above) is a must-have feature in the inner tent to protect your sleep system from getting wet.
The inner tent connects to the outer fly at the two apex points (above your trekking poles or tent poles) using glove clips which are easy to attach or detach. It also connects to the four corners of the outer tarp along the corner seams and stake out points so it’s suspended from the outer fly. For full pitching instructions, see Yama Mountain Gear’s website.
The resulting pitch provides a wide gap between the outer fly and inner tent that provides excellent ventilation and interior volume. Air flow through the Cirriform DW-1P is excellent and the only time I experienced any internal condensation (on the inside of the outer fly, but never the inner tent) was during heavy rain storms when I pitched the outer fly low to prevent rain splash-back.
Ease of Pitch
Pitching the Cirriform DW-1P is easy as pie. Simply stake out the four corners of the outer fly, insert your front trekking and rear pole in the apex points at the end of the shelter and tension the corner guys, which have linelocs attached. In dry weather, it’s best to keep the inner tent attached to the outer fly when pitching if you know you’ll want both at night, because it makes setup slightly faster.
If you want to get fancy, you can position the rear trekking pole off-center in order to pull out the rear beak for better rear ventilation or raise or lower the outer fly for better ventilation/more wind protection, depending on conditions.
In practice, you need 7-8 stakes to pitch out the Cirriform DW-1P, depending on the configuration you want. I only stake down the middle fly guy outs when I know it’s going to storm (rain) at night, but I bring very lightweight titanium shepherds hooks for this purpose. On the corners and apex guys, a 6″ Easton stake is more than sufficient for staking out the tarp.
Silnylon vs Cuben Fiber
Yama Mountain Gear makes the Cirriform DW-1P reviewed here in both silnylon and cuben fiber depending on your preferences and weight needs. I bought the silnylon version (list price $250) because it was more affordable and because I try to review the version of a shelter that most people can afford.
Incidentally, the blue color silnylon shown here is awesome. It’s translucent inside, allowing some light to filter in, but without cooking you like translucent cuben fiber in hot sunlight.
After speaking further with Yama’s owner, Gen Shimizu, I realized that the silnylon version of this shelter is somewhat easier to pitch because it has more stretch to it than a rigid fabric like cuben fiber. If in doubt about which fabric to choose, or about the pros and cons of the single-walled Cirriform shelter, I recommend you call Gen and talk to him. He has some very interesting insights into the durability pitfalls of cuben fiber, which is the reason he offers this shelter in both fabrics.
The Yama Mountain Gear Cirriform DW-1P double-walled tarp shelter is a versatile shelter system that can be used in a wide range of weather, including wet weather. Easy to set up and with a separate inner tent that can be left home to save weight or used as a bug bivy in shelters, it provides backpackers with a lightweight shelter option without skipping on comfort or utility. Available in both silnylon (and cuben fiber), it’s also surprisingly affordable compared to the runaway prices of other ultralight shelters these days.
- Easy to pitch
- Excellent ventilation
- Separate inner tent can be used alone or left at home
- Three-panel vestibule provides more interior volume and better livability
- Pacer Pole compatibility
- Impeccable build quality
- Manufacturer does not provide a seam sealing option on the silnylon version. You have to DIY.
- Capacity: 1 Person
- Packed size: 10″ x 7″ x 5″
- Interior height: 36″ (head) 21″ (foot)
- Int. width at ground level: 34″ (head) 22″ (foot)
- Int. width at top of tub: 37″ (head) 25″ (foot)
- Int. length: 84″
- Tub height: 8″
- Floor area: 16.3 ft2
- Stakes req’d: 7 minimum, 9 recommended
- Weight before seam dealing (mfg supplied)
- Rain fly 14.2 oz
- Inner tent: 10.8 oz
- Guyline: 1.2 oz
- Linelocs: 0.5 oz
- Shockcord: 0.8
- Grommets: 0.3 (removable)
- Total weight after seam sealing: 25.5 oz on SH’s scale (yes, this is less than the mfgs weights would indicate).
Disclosure: Philip Werner purchased the Yama Mountain Gear Cirriform DW-1 with his own funds.