Volume reduction to go SUL

Not unless there’s a compelling reason – i.e. if I’m using an especially small pack, need more room for food/water, or want an especially low-profile pack for moving off-trail or running. Small packs have become a preference for moving fast and reducing bounce, so I often do compress my soft items with a SUL kit. At these weights, I find the way a pack carries matters more than the weight of an extra stuff sack or two for comfort and ease of moving fast.

Yes, small is good. Generally smaller is lighter, but not always. Use a compression sack, it means you will have to fluff up your bag for a few seconds. A dry compression sack, like the Sea to Summit eVent bags is more than worth it.

when I’m going (or approaching) SUL, it means I’m running or walking really fast :)  so low volume is as much a premium as low weight- thus quilts, jackets, etc get really compressed, as does anything else I can make smaller

There’s debate about whether or not severely compressing down bags/garments is harmful to them, so I don’t go as far as compression sacks. I do however cram my down bag pretty aggressively into a ZPacks roll-top dry bag. Any garments I want to keep dry I shove into HMG CF-8 stuffsacks. I never use pack liners…hate em.

Compression bags also weigh about twice as much as cuben roll-tops.

If you’re going to use a pack liner then an HMG CF-11 stuff sack would work great for your quilt. CF-8 isn’t really strong enough for the forces of ramming something as large as a bag/quilt. The cuben stuff sacks are a little lighter and cheaper than the cuben roll-tops. They’re waterproof, but not submersible.

Normally I don’t use many stuff sacks, especially not for the quilt, but for SUL-ish loads with frameless packs I like to use stuff sacks and place them horizontally in the pack. Lets the pack conform better to my back than the ‘sleep-pad frame’ or ‘burrito frame’ methods.

I found that without stuff sacks the quilt and other puffies would expand and give the pack a sausage shape that created a narrow contact area down the middle of my back, causing the pack not to ride well and to sway side to side.

I’m really confused.  Unless you’re going off trail, in really brushy areas, why do you care about the volume of your pack.  If the volume is too big then get a smaller volume pack.  Adding stuff sacks or compression sacks only adds weight.

I had a similar problem as I lightened my load.  My pack was too big.  I ultimately found that it was better to stuff my bag and other puffys into the pack unstuffed in order to have it fill out the volume.  I found that doing so made it carry better and more comfortably.

“I’m really confused.  Unless you’re going off trail, in really brushy areas, why do you care about the volume of your pack.  If the volume is too big then get a smaller volume pack.  Adding stuff sacks or compression sacks only adds weight.”

Well, yes, I see your point. But there is the weight of the back pack to be considered, too. For a typical trip out, say about a week, I went from a 17oz Miniposa (around 3000ci)  pack to a 12oz pack (Murmur-around 2200ci) using a 3.7oz eVent compression sack(6″ diameter.) When that one dies (I have had it for 4 years or so) they also make a lighter version at 2.3oz. By saving the volume with a compression/dry sack, it lowered my overall base weight by about 1.3oz. The sack also doubles as my pillow making me more comfortable. (I can stuff it with most anything once I turn it inside out, even sand and light gravel or forest duff.) It also doubles as a water carrier from a water source to camp letting me wash up easier with water warmed up by the camp fire (where fires are allowed.) It is really waterproof letting me drop any pack liner(another ounce or so) and still keep my sleeping gear dry (I have flipped my canoe in the past so it has been “tested.” I was soaked, but my sleeping cloths were dry and warm.) The only downside is the buckles. They are all over the top and one catches as I drop it into my pack.

Overall, the eVent bag is more than worth it for reducing volume. I was headed out for a week, headed to a camp site, right after a resupply and another UL hiker was coming the other direction. He was astounded that I was set up for the week carrying a “glorified purse”…his words. The smaller pack was also easier to carry because it balanced better on my back.

I usually stuff my quilt into the bottom of the pack. I put my puffy and clothes I’m not wearing into a Cuben sack, which isn’t a tight fit. I find that when I try to compress down into tiny stuff sacks I end up with areas in the pack that I can’t fill with gear. I can get all my gear into a zPacks small Zero for most 3 season 3-day trips if I don’t need to carry much water.

If dropping 1.7oz from a weight perspective is important, and you’ve got the money, then go for it.  Lighten up!

What i’ve found is that going SUL is not about your pack but about continuing to lighten your sleep gear, shelter, and warmth layer.  I tried to go SUL several years ago and found that i didn’t like the exposure that my tarp-based shelter offered…much less the lack of headroom to enter and exit the shelter.

I found, however, that once i lightened my shelter (Solplex), sleep gear (Zpacks 30 degree bag), and warmth layer (OR puffy), i was under the SUL weight limit by complete surprise.  Previously, i was around 6.5lbs base weight and happy.  After upgrading my shelter and bag, I’ve even more happy but only but 2 lbs.

Net-net, the more you stress going from UL to SUL, the worse it gets.  Continue to make cost effective upgrades to your gear,without sacrificing comfort then you made surprise yourself…like i have.

add running to “off trail, brushy” for low volume advantages

Thank you all!

As I’ve actually added some weight back to my base weight (as many of us have after see the weight plunge), I have regained some desire to “lose more weight” again – not to earn a new label, but to push myself.

I’ll start scrunching up my stuff to reduce volume soon.  And Kevin, you’re right that pack weight itself isn’t as big a deal as other gear – at least for me.

Todd, I don’t know which pack you’re using, but after you get your SUL-ish kit dialed in you might find that the pack capacity is so much more than what you need that a smaller pack is beneficial.

That is certainly what happened in my case, where my Arc Blast 52L simply dwarfed the load and everything ended up in the bottom. Even without a stuff sack my 11-oz EE quilt got smushed down to nothing, and it and all the other stuff ended up in the lumbar area, occupying about 40% of the available volume.

I got an MLD Core (1700ci/28L, with 2 shoulder strap water bottle pockets) for the 1- to 2-night quickies (true SULers could go longer!) and also lucked up and got a good deal on Gear Swap for a Zpacks Zero hybrid/custom (36L) that I use for longer trips. The Arc Blast is still my mainstay, but these smaller packs have their niche. The weight savings is incidental, but even there the 8-10 oz reduction is considered a pretty hefty chunk by SUL standards.

Yup, I agree with Bob. Most of the extra weight I carry is from comforts, not really because they are “necessary.” You will likely have two or three packs that will fit the length of trip you will be doing. Volume reduction roughly means weight savings and a half pound anywhere is a good savings. After getting down to SUL weights (4#11 with the G5,) I added comforts and went back to an 8pound base weight. Pretty much the same gear, using the same skills, but with a lot of additional comforts. It has been referred to as “comfort” packing…

So what volumes (and specific types of packs) are most SUL backpackers using?  I would have expected John Abela to have already done a comprehensive comparison of SUL backpacks, but I can’t find one.  Perhaps there’s just too many compared to available SUL complete shelters.

I have a couple cheap 20L 4-6 oz daypacks that I’ve been using for my training hikes this winter.  Volume-wise they seem possible for multi-night trips. I’m still working on putting together/MYOGing my UL/SUL gear for the summer, so I haven’t tried packing them yet with my full 5-day gear and food.  But I’d appreciate more features than they have like a waist-belt with pockets, and a front mesh pocket.

I’ve been considering purchasing one of the running packs in the 20-25L range that are popular for multi-stage ultramarathon races (see this thread for a list of some https://backpackinglight.com/forums/topic/45077/page/2/#comments).  In general, these are a bit heavier than a ZPacks Zero or MLD Core (at least base versions of these with minimal features), but it seems like the running packs might be more comfortable in the 15 lb range.  I think Marathon des Sables requires racers to start with a minimum 14.3 lbs minus water.

I had my UD Fastpack 30 out yesterday for a 25-ish mile spin (about 6-7 of those on snowshoes)- the pack was loaded to right at 15 lbs with food/water/snowshoes- this was a training outing for the upcoming Bob Open so I loaded everything I plan to take for a 3-4 day trip.  I was very happy with the way it carried.  I replaced the provided back pad w/ a GG sitpad and the pack weighs right at 20 ounces now