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MYOG Part 4: Sleep System

[Editor's note, I know this is technically the first published, but I wrote it as the 4th in the series. Read them in any order and  they should still make sense. Also, I get asked a lot of questions about my tarp.]

MYOG Sleep Systems, introduction

Canada can get cold. The Canadian Rockies can get even colder. I like to sleep comfortably and warm, but I’m lazy and I don’t like to carry a lot of weight. My current system of a tarp and quilt is what I consider a great compromise between weight and warmth.
When I started out, I used a commercial down sleeping bag, and a backpacking tent. These can be great, and modern tents have come a long way in the last decade. 10 years ago, 5 pounds was considered light for a 2-person tent. Now, I have a commercial 4-person tent that weighs 3 pounds with a pole and mosquito net insert. Weight is no longer really the savings when making your own gear.

Most of my backcountry trips seem to involve rain or snow (except if I bring my friend Jeremy, who also does not mind adverse weather). A few years back, I did some experimentation to see what would happen to my sleeping bag after a few days of sleeping out. I was surprised to find that my sleeping bag took on several hundred grams of moisture the first night of sleeping in a tent. Even with draping my bag out in the sun to dry, by the third night I was sleeping in a less effective, and heavier system.

But Why a Tarp?

This is part of how I came to be sleeping under a tarp. Sleeping outside greatly reduced the amount of condensation in my sleeping bag, but if it rained, the rain would get in. My bivy sack had the same problem as the tent. The tarp would keep the rain off me, but trapped far less condensation in my bag than the tent. I used a commercial rectangular tarp for a few years, but found it was hard to pitch so that it consistently kept out the rain. In other words, I wanted a custom tarp. The other half of the tarp origin story is that we “allowed” Fiona to sleep out under a tarp with me one night and she awoke in the morning and said, “I only sleep under tarps now, no more tents.”

Tarp Design

There are about 7 million tarp designs available on the internet, and I took ideas from a few of them. I wanted it to shed wind and water better than a rectangular tarp, so I made it with a catenary cut ridge line and front. I also wanted not to adjust in the middle of the night, so I chose silpoly as the material for minimal stretching. I also wanted light weight but enough durability to hold up in a substantial wind.


The holy grail of bikepacking tarps is one where your bike fits inside, or can be used to support the tarp. I also hike and ski, so though I think bike-supported are extremely cool, I opted to use bike supports only for treeless bikepacking situations and use hiking/ski poles as primary supports where trees are not available. The tarp weighs in at 300g, so it ended up being on the lighter end of the shelter scale.

The silpoly does not stretch in the rain and doesn’t need to be re-tensioned when it rains. I do not recommend it as an easy fabric to sew, it is like sewing live squirrels to each other.

Quilt design

Not Exactly a Bed Quilt

Since I’m foolish enough to think that winter is the primary bikepacking season, I wanted to have some versatility to my sleeping bag system. I wanted lighter weight in summer, I wanted synthetic material for the outer since down performs so poorly in wet conditions. I wanted light weight since my daughter would be carrying one.
In the 80s, I used a dual bag system of a sleeping bag with an overbag. I really liked it, but I had also been interested in quilts as an alternative to sleeping bags. I talked up the concept of a down bag with a synthetic quilt over it for cold, with the quilt on its own for more moderate temperatures (well, moderate for the Canadian rockies). Camping quilts are not exactly like a bed quilt, they are usually shaped in some way, and many (like mine) have a footbox like a mummy bag and a drawstring closure at the top.

Testing the new quilt

The home made portion of the combo ended up as the quilt – down sleeping bags are relatively available, and affordable. I used Climashield Apex as my insulation layer and the lightest nylon I could find, Membrane from RSBTR. The sleeping quilts have simple ribbon loops to attach them to a sleeping mat, so they can tuck under the sleeper at the sides, and they work well down to about -10ºC.

The quilts being about 800g each puts them as competitive weight wise with the commercial versions, but they were about half the price to make as the commercial equivalent. In winter, adding a -10ºC sleeping bag yields a combination that is comfortable below -30ºC, theoretically to -40ºC, but we have not been out that cold since I made them.

No Hood, No Problem

A big problem for me with traditional mummy bags has been that the hood can end up in the wrong spot when i roll over, and then the hood fabric gets wet from breath condensation. With the quilt, this doesn’t happen since the quilt lacks a hood. To deal with the lack of hood, I made sleeping hats from the same material as the quilts themselves. the hat acts like a hood, but turns with the sleeper allowing them to not get wet from breath.

 

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