How low in Temp can you go SUL?

Aaron,

Here is my 30* wet SUL gear list. I have been very comfortable with these core items at 30* in week long rain and light snow. Some of the smaller items I have less experience with as I am always trying to find lighter items. My main limitation with this set up is I only like to use it for 2-3 day trips otherwise the food weight gets to be too much and the pack doesn't feel good on the shoulders. For longer trips, I swap out to a pack with light suspension and usually add a few more items and end up in the 6 pound range. I have been using these core items (shelter, sleeping pads, quilt, clothing, cook kit, etc.) for quite a few years in the Winds, Unitas, Colorado and feel very safe in just about any condition above 30*.

I do currently own a silnylon version of the MLD Serenity Shelter (3 oz heavier than the CF version) and a CF version of the Patrol Shelter and was waiting to see if I could get under 80 oz before I dropped the $$ on the CF Serenity which I plan to do soon now that I figured out a way to make my SUL goal. My goal has been to try to create a sub 80 oz kit that would keep me safe, dry, warm, comfortable, and bug free in most 3-season mountainous alpine situations with lows of 30* and I think I am getting close to getting there.

Hope this helps.

Rick

30* wet SUL Gear List

Zpack Zero – Small
Lightweight Trash Bag Pack liner
MLD Patrol & Serenity Shelters, Cuben Fiber
(4) 0.2 oz Ti stakes & (6) 0.035 Terra Nova Stakes
GG NightLite Pad
MLD 1/8” x 70” CFF pad
Zpacks 30* Quilt
Pillow / Extra Water Carrier – Gallon Ziplock
Trail Design GVP Caldera Cone Stove, Foster's Pot, Lid
Bic Mini Lighter
MSR Folding Spoon
1L Water Bottle
Aqua Mira in mini dropper bottles
Montbell EX Light Down Jacket, XL
REI Fleece Hat
PolyPro Glove Liners
2nd set of socks
Cuben Clothing Stuff Sack
Zpacks CF Rain Jacket, XL
Zpacks CF Rain Pants, L
Zpacks CF Rain Mitts
Suluk46 Ti Potty Trowel
3ml Hand Sanitizer bottle, 2 ziplocks, TP, wet ones
Petzel e+LITE Headlamp
CF Bear bag, Rock Sack, & line
Driver’s License, credit card, cash
Bandana (1/2)
MLD Head Net
First Aid Kit
Eyeglasses (back-up for contacts)
Bubble Wrap Eyeglass case, Rubber band
1 Edge Razor (in cardboard sheath)
Blister care (in first aid kit)
Lib Balm
Contact Case
1 extra contact (in first aid kit)
Ziplock for small above items

Total Weight 4.93 pounds

I miss this kind of thread. I like it.

Impressive.

My baseweight is about 12 pounds, so not SUL

down to 32 F – all MYOG

long WPB jacket – 12 ounces
nylon shirt – 10 ounces
nylon pants – 8 ounces
synthetic vest for camp – 8 ounces
fleece hat – 2 ounces
down bivy/quilt – 23 ounces
mid – 14 ounces
pack – 16 ounces
tent poles which are part of the pack – 4 ounces

down to 20 F – swap out synthetic vest with a down vest – same weight

Aaron,

I have posted this trip report (with gear list) many times on BPL. I don’t do well in cold so just below freezing is where I need to start adding stuff that really ups the weight.

Also, if the temps drop below 50F, I need to keep hiking all day with SUL gear and can’t sit around much in the evening when it goes below 40F unless I wrap my quilt around me. With this kit I need to be very careful my down stuff stays dry.

Aaron,

It looks from your list that you're OK to 32 -30 F. with your quilt.

But… quilts are just not as thermally efficient as full on mummy bags so if you want to go lower and still stay SUL (relative to winter temperatures) I'd advise a 0 F. bag or at least a 20 F. bag and wear your insulating clothes inside as needed. Be sure the bag has enough girth to accommodate your puffy clothes without compressing the top insulation of the bag.

SUL has to be about Multiple Use as often as possible and wearing puffy trail and/or camp clothes inside your bag is just that.

Plus zipping up your WPB parka and putting it over the foot of your sleeping bag helps add warmth and protect the bag from getting wet when the warm foot of your bag touches the frosty wall. ** Pull parka sleeves inside and cinch the hood all the way down, slide the parka on foot of bag and cinch the bottom of the parka a little if it has a drawcord.

If you trawl through our archives far enough, you will find a long saga about how Ryan J went SUL (ie <5 lb) in the snow once for a weekend. His biggest problem was that it was too WARM – and the snow melted. Dry snow is good, but wet melting snow was hard.

Cheers

I also thought that quilts were just not as thermally efficient as full on mummy bags. I had heard this from lots of hikers and from every sales person I brought the question to. However, in order to reach my SUL range goals, I had to drop weight in a few places and my sleeping bag was one of them. I decided I would do some actual quilt verses mummy bag testing in my back yard to see for myself.

I bought a digital thermometer, several different sized quilts, and a down hood. I kept my sleeping pads and shelter set-ups the same, yet experimented with all other options on winter nights with lows around freezing. To my complete surprise, I was actually warmer in a Zpacks 30 degree quilt and down hood than I was in my 20 degree, Western Mountaineering Alpinelite mummy bag. Even more surprising, I was warmer in the 6’1” quilt and hood than I was in a 6’5” quilt and hood even though I am almost 6’ 5” tall. These results were based on how I felt and from digital thermometer readings taken from inside my bag.

I believe the “too small on paper” quilt was warmer than my WM mummy bag because it fit my body the best without any waited space inside the bag. I always thought I had to buy x-long and extra wide bags for space comfort, yet, these bags were actually too big. The long (6’1”) quilt and hood just worked perfectly for me, and, I would have never thought so unless I would have experimented with it all. I was not cramped at all. Dropping a full pound in weight and actually being warmer was a very pleasant outcome along with the added bonus on now knowing how much I like rolling over in a quilt and hood compared to a mummy bag.

I believe that getting to SUL is a lot about experimenting with new things and thinking outside the box. I never thought the shorter quilt had a chance to work, yet, I liked the weight so I gave it a go. I also understand many wouldn’t want to go through all this and I get that too. For those of us who enjoy it, it is actually a lot of fun and every so often we strike some gold.

> I was actually warmer in a Zpacks 30 degree quilt and down hood than I was in my
> 20 degree, Western Mountaineering Alpinelite mummy bag.
Ah, this is well-known. Light-weight Gear 101.

With a sleeping bag you are carrying around a whole lot of down and fabric which gives you no warmth at all, since it is squashed flat underneath you. That's the whole point of a quilt: ALl the weight of down is on top of you, insulating you.

Yes, both SBs and quilts do require a good mat under you, but the requirements are about the same for the two styles. No, an SB does NOT make a mat any warmer.

Cheers

"and from every sales person I brought the question to."

Rick, there's a good reason why every sales person you've spoken to about Mummy SBs vs Quilts tells you that…its because rarely does a sales person in a store sell a quilt! Usually, they don't stock them. If they told you that a quilt is definitely better, you'd walk away and buy a quilt online.

I only sleep on my side, so I figure that the down being compressed is a lot less.

Also being a side sleeper, I was always paranoid that there was a draft near my back every time I rolled over. 1/4 of the time there was. If I were a back sleeper, it would be very easy to tuck everything under and check for drafts.

Also found that insulating your head is very efficient. A hood from a down jacket was not enough. Having a hood from a down jacket and a hood from a sleeping bag combined does a lot for warmth for me.

Just my 2 cents on sleeping bags vs quilts. Seems to be a preference thing.

Drafts can be an issue with quilts. But, i've found that sewing some UL less breathable fabric to the bottom of a quilt to form a sleeve can really help with that. Yes, it adds a little weight, but still lighter than sleeping bags. For one of my winter quilts, i used M50, which is UL and not very breathable. Makes a difference when it's really cold and the wind is whipping up.

For such a flap, the lightest weight cuben could be used just fine. Javan Dempsey used to do some of his quilts with a well designed flap. Worth looking up. I think more modern strap systems negate much of this issue. Some of them could be complimented by a small strip of flap edging in addition (add a few grams total to a set up) that could be tucked under pad.

Ime the strap system is ok and does basically work, but last time i was out during a polar vortex system, and it was around -3 F* for the low, without windchill and it was windy, i really did appreciate that fabric sleeve, as it's full fool proof and i can roll around, toss and turn, and not feel the draft like i sometimes felt even with straps. I don't know exact weights, but i bet if you add up the side buckles and straps, it wouldn't weigh much less than a yard of UL fabric, and that's all you need for a quilt if you're average size or below (most rolls come 60 inch wide, then 3 feet long for a yard, but you use the width part for the long side, minus the foot box area which really should just be sewn up for a winter quilt anyways).

Yes at that temp (well and truly sub freezing) going the full flap and straps is really a good idea, I agree.

“SUL” is a very relative term when referring to winter weather. Going SUL obviously means going heavier than in balmy summer months but still going as light as possible. However winter weather is much more unforgiving and therefore dangerous. I cannot overstate this.

Winter means taking clothing that will be warm enough to easily prevent hypothermia and shelter that will protect you from the worst that can reasonably be expected – not just what is forecast for your trip.

1. All garments should likely be down and commercially DWR treated down if possible to avoid losing loft/insulation. This includes DWR treated sleeping bags when possible. (I am not a fan of quilts in winter. They are not weight OR warmth efficient compared to mummy bags.)
2. Mattresses need to have a decent R value for the temperatures expected. Big Agnes has some of the lightest insulated mattresses – IMHO.
3. Shelters should protect from high winds and spindrift snow. If this means building snow “walls” to protect tarp edges then reserve time to do that before sundown. Building snow caves or Quinzhees is nice IF you have the time or are building a base camp. I prefer light double wall tents. One two person tent is lighter than two solo tents. Jus’ sayin’…
4. VBLs for boots are virtually mandatory as are removable insulating liners. They go in your bag to be warm for the morning. Boot tops are telescoped over each other to keep snow out if stored in a vestibule. For max. warmth I like seam sealed neoprene foam VBL sox with light polypro liner sox.
5. Gloves &/or mittens need to be WPB shells that have removable liners (at least one spare liner) to change out when they get very damp from sweat. Mitten shells are a must if near zero F. temps are expected. They are much warmer than gloves.
6. A balaclava can be worn day and night to save weight.
7. My weight saving stove is a Trail Designs Sidewinder ti stove with the Inferno woodburning insert IF dead wood branches are available. All I need to carry is ESBIT for tinder.
8. And then there is the necessary snow travel footwear such as skis or snowshoes and the correct boots – plus ski poles. It is very difficult to go SUL here. You can try to get the lightest gear but it’s ‘spensive.

That’s about all I can think of for SUL winter travel tips. Obviously if you are traveling in avalanche territory you need:

1. ALL members of the party to be Avalanche Level One trained and equipped for rescue WITH every member carrying an avy beacon
2. At least three people in a group.
3. ALL carry a SPOT or other emergency beacon or sat. radios

Eric,

There are a lot of places in this world with winter or even fall and spring temps that have a high of 45-50 and lows of 15-20 and without any snow.

On top of that, any place I would go SUL in these temps would not be in locations with high winds or possibilities to drop another 10-15 degrees on any given night.

I could easily piece together an SUL list that I could be comfortable with lows at 15 degrees.  It wouldn’t be a full mountaineering list but just an expansion on my 30 degree sub 4 pound list.  A pound of warmth can go a long ways.  Another 6 ounces of down in a quilt, a 5 ounce warmer jacket and 4 ounces in the legs could get me down to 15 degrees.

My hammock system is tested comfortably down to a breezy 35 degrees. There are some really easy ways i could shave about a pound but i’ve grown attached to some things.

My total is 60.6oz

I dont often do more than an overnight, if i went longer i would need to lash stuff onto my pack. I dont have a full list but here are the highlights

Pack-Zimmer Daypack 6.7oz

Sleeping Bag- WM Everlite 14.5oz

Hammock- Eno sub7/amsteel blue suspension 8oz

Lighting/batteries- Zebralight +2 batteries 2.4oz

Solar charger (for phone and batteries)- Voltaic 2w, xstar cr123  4.7oz

Tarp- Hammock Gear Asym 4.3oz

Knife-Flyweight 3″ trout knife 0.13oz

Pot Klean Kanteen 16oz food canister 7.3oz (huge waste of weight but i love it)

Stove- myog alchy 0.4oz

CLOTHING not always worn

Arc Cerium LT vest 4.2oz

Hot Pack ultralight Jacket 1.8oz

Stoic socks 1.7oz

Coal Emmerson wool beanie 2oz (LOVE THIS BEANIE)

WM Flash booties 3oz

I could definitely refine this list but im not as obsessive as i used to be. I think it still qualifies as SUL though. Grrr that stupid pot weighs as much as my hammock and suspension. oh well. love that pot.

All Smiles

That is light mr. Hoffman!

If one could count on building a snow tunnel/trench for a hammock setup the same weight would go to pretty low temperatures (and tarp could be omitted). That approach is sure risky and better classified to Stupid Light -category.

I have gone from Hammock-inside-sleeping-bag back towards sleeping on the ground as I just find it more comfortable except in snowy conditions on forested area. It’s just so easy setting up a hammock camp and being high and dry above the snow.

That would be sweet to dig a trench in 3 or 4 feet of snow with the hammock below the surface. Could  pretty much just drape the tarp over the top. Even without a roof that would be pretty cozy.

My SUL list has changed a few times since I first tried it in 2008. My current iteration comes in with a base pack weight of 3.93 lbs and 4.27 worn. It is really only comfortable to about 50 degrees without shivering though (which is very impractical here in Montana so I rarely go out SUL honestly). I can swap out my 11 oz quilt for a warmer one and bring this temp down much farther with very little extra discomfort.

Bear Spray – 12.30
Compass – 1.90
Documents – 0.40
Map – 0.50
Sunglasses – 0.63
Socks – 1.50
Shoes – 31.48
Gloves – 2.30
Hat (warm) – 0.60
Hat (sun) – 3.25
Pants – 10.53
Jacket (insulating) – 11.00
Shirt – 6.00
Utensil – 0.25
Cookpot – 1.00
Stove – 0.40
Fire starting kit – 1.00
Water bottle – 1.25
Water treatment – 0.48
Headlamp – 1.00
Flashlight – 0.24
Watch – 1.90
Blade – 0.25
Whistle – 0.20
1st Aid/Hygiene – 2.02
Backpack – 4.40
Pack liner – 2.00
Stuff Sack – 0.24
Bear Bag – 2.00
Wallet – 0.06
Guy lines – 0.70
Sleeping Pad – 6.00
Sleeping Quilt – 11.00
Stakes – 1.30
Poncho Tarp – 11.00

……………………….