Reviews > Sleep Gear > Sleeping Bags > Functional Design Sweetie Pie Doubler > Owner Review by Benjamin Rakestraw

Owner Review: Sweetie Pie Sleeping Bag Doubler
Date: April 29, 2006

Reviewer Information:

Backpacking Background:

After a couple of years of day hiking and car camping, I began backpacking just over one year ago. I immediately valued the concept of lightweight backpacking, and attempt to keep my gear as light as possible, but within reason. I enjoy being comfortable while I hike and camp. My pack weight for an overnight trip is around 20 lb (9 kg), including food and water. From spring to fall, I go on many overnight trips in western Pennsylvania , a few multi-night trips in the surrounding area, and one longer trip in one of the National Parks. My hiking companions include my girlfriend and dog.

Product Information:

Product Description:

The Sweetie Pie Sleeping Bag Doubler converts almost any mummy style sleeping bag into a sleeping bag big enough for two people, and allows couples to sleep and snuggle together comfortably. The majority of the Doubler’s width is in the shoulders and hips, while it quickly narrows down towards the feet. As an added benefit, the Doubler can allow significant weight savings if carrying one sleeping bag plus the Doubler vs. two separate sleeping bags.

The Doubler is insulated with Polarguard 3D and comes in two weights: Summer (40° F (4° C), 12 oz (350 g), as tested) and Three-Season (10° F (-12° C), 25 oz (690 g), not tested). The fabric of the Doubler is 50 denier ripstop nylon. The Doubler uses standard #8 YKK zippers, and zips into any mummy bag with full length #8 YKK zippers. Sleeping bags with 1/2 or 2/3 length zippers will not work with the Doubler! It can also zip into itself to form a small, child size sleeping bag.

The Doubler is ordered online direct from the manufacturer, Functional Designs. It comes well packaged and with a large cotton storage sack. It does not come with a stuff sack.

Product Review:

I have used the Sweetie Pie Bag Doubler on many trips over the past year, in overnight temps ranging from 32° – 75° F (0° - 24° C). Weather conditions have included cold and dry, cool with light rain, and warm and humid. Elevations have ranged from 500 to 1200 ft (150 – 365 m) in the hills of Pennsylvania and up to 5000 ft (1525 m) in the Smoky Mountains . The Doubler performs exactly as intended; it allows a couple to sleep together comfortably in one sleeping bag. It is well made and seems durable enough for many years of use.

Much of the Doubler’s performance (room to move, warmth, ease of packing, zipper performance, etc) is dependent on the sleeping bag it is zipped into. I have used the Doubler in two different sleeping bags and will give a perspective based on my use. I should note that I do not always use the Doubler in the way the manufacturer seems to intend. The manufacturer implies that the Doubler will be the “top” of the two-person sleeping bag. However, this seems silly when the Doubler is paired with a high quality down bag, as the warm down is useless when compressed underneath me. When the weather is cool or cold, I arrange the down bag to be on top, while on a warm night, I will arrange the Doubler to be on top.

The roominess of the Doubler depends on the roominess of the sleeping bag. I have used the Doubler in both a “normal” sized sleeping bag and a “snug” sleeping bag. Both my girlfriend and I are quite small and sleep close to one another, and we prefer a smaller shared space. Zipping the Doubler into a snug sleeping bag provides just about the right amount of space, but having a couple inches less width would be even better. Average or larger sized people may prefer to use an average or roomier sleeping bag with the Doubler. The Doubler also provides adequate space for other nighttime activities when a couple does not want to sleep.

When using the Doubler, two people share the same foot box. The shape of the foot box depends on the length of the zipper on the sleeping bag. Sleeping bags having a slightly shorter zipper (but still full length) will create a narrower foot box. This does not bother me, as my girlfriend is significantly shorter than me, so only one set of feet (mine) is actually in the foot box. However, the narrow foot box may affect couples of relatively equal height.

When using the Doubler as the top of the sleeping bag, the description of the Doubler being “summer weight” is accurate. The warmth of the Doubler is adequate for cool nights, though the 40° F (4° C) rating is optimistic by 10 degrees F (6° C) or so. When the sleeping bag is arranged to be on top, the warmth of the Doubler is slightly less than that of the sleeping bag itself. The extra space created by the Doubler is not fully taken up by the additional person sleeping inside, therefore more air needs to be heated inside, and bag is not as warm. Here is where having a snug sleeping bag (i.e. less air space) has its advantages. As the thickness of the Doubler itself has little effect on temperature rating when arranged to be on the bottom, I wonder why one would ever need the “three-season” weight Doubler. When using the Doubler with a snug 20° F (-7° C) down bag, the coldest temperature I have used it in was 32° F (0° C), and that was coldest I would want to go without piling on more layers of clothing. Also of note is that only one hood is available when using the Doubler (the sleeping bag’s hood), which significantly effects how warm the bag is. I wear a hat on cold nights, but would likely sleep in a separate bag from my girlfriend if I expected the night temperature to dip below freezing.

Use of the Doubler can provide significant weight savings. When the 12 oz (340 g) Doubler is combined with a typical 2 lb (.9 kg) down sleeping bag, the combined weight is only 2 lb 12 oz (1.25 kg). This is much lighter than the 4 lb (1.8 kg) combined weight of two sleeping bags. However, while writing this review, I weighed my Doubler for the first time, and found that it weighs 18.7 oz (530 g). While I didn’t expect the weight to be exactly 12 oz, I certainly did not expect it to be nearly 7 oz (190 g) over the manufacture specified weight!

The Doubler does not come with its own stuff sack. At first I thought this was a mistake, and I emailed the manufacturer that I did not receive one. When they replied, I learned that the intent is to leave the Doubler zipped to the sleeping bag at all times, using the sleeping bag’s stuff sack for both bag and Doubler. With a very compressible down bag and somewhat generously sized stuff sack, the Doubler and sleeping bag just barely fit in the stuff sack. Stuffing the Doubler and a synthetic material sleeping bag into the same stuff sack could be more challenging, if not impossible. However, leaving the Doubler zipped to the sleeping bag at all times is very convenient.

The zipper on the Doubler occasionally snags on the fabric, but not enough to be an annoyance. The combined zipper mechanism between sleeping bag and Doubler works just as smooth as the sleeping bag zipper itself, and having a zipper on each side of the doubled bag allows either occupant to leave the bag easily. The fabric on the Doubler seems durable enough, but I haven’t abused it. I also haven’t gotten the fabric wet enough to test the limits of its water repellency, but it seems to hold up to a few drips of condensation very well.

Summary

The Sweetie Pie Sleeping Bag Doubler is an excellent product that performs as intended. It allows a couple to sleep together in one comfortable sleeping bag.

Pros:

• Proper size. Provides an adequate amount of room for two people.
• When combined with a warm sleeping bag, is adequate three-season use.
• Provides significant weight savings over two separate sleeping bags.
• Fits in sleeping bag stuff sack. Can be left permanently attached to sleeping bag.

Cons:

• Slightly narrow foot box.
• The extra air space created reduces the temperature rating of the attached sleeping bag.
• Only one hood available for use (the attached sleeping bag’s hood), reducing warmth.
• Weighs nearly 7 oz greater than the manufacturer specified weight.

Reviews > Sleep Gear > Sleeping Bags > Functional Design Sweetie Pie Doubler > Owner Review by Benjamin Rakestraw