The world's most in-depth and scientific reviews of gear

Sea to Summit Ultra-Sil Day Pack Review

A bare-bones ultralight pack for those really dedicated to cutting ounces.
  • 1
  • 2
  • 3
  • 4
  • 5
Price:  $35 List | $31.30 at Amazon
Pros:  Insanely light, packs up super tiny, fits slightly larger people
Cons:  Nearly no features, only one big pocket, super thin fabric, can feel contents
Manufacturer:   Sea to Summit
By Maggie Brandenburg ⋅ Senior Review Editor  ⋅  May 14, 2019
  • Share this article:
Our Editors independently research, test, and rate the best products. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Learn more
54
OVERALL
SCORE


RANKED
#11 of 12
  • Comfort - 25% 3
  • Versatility - 25% 5
  • Weight - 25% 10
  • Ease of Use - 15% 4
  • Durability - 10% 3

Our Verdict

The Sea to Summit Ultra-Sil is an impressively small, lightweight pack that minimalists are sure to love. For just a couple of extra ounces, you can clip this packed up pack just about anywhere and be adventure-ready. A super thin design keeps this bag reasonably comfortable and by removing nearly every extra feature, the Ultra-Sil is the lightest pack we tested. This loss of organizational pockets and use of thinner fabric cuts into the versatility and durability of this bag a bit.


Compare to Similar Products

 
Awards  Editors' Choice Award  Top Pick Award  
Price $31.30 at Amazon$119.99 at Backcountry
Compare at 2 sellers
$129.95 at Backcountry
Compare at 3 sellers
$109.95 at Backcountry
Compare at 3 sellers
$124.98 at Amazon
Compare at 2 sellers
Overall Score Sort Icon
100
0
54
100
0
81
100
0
78
100
0
75
100
0
72
Star Rating
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
Pros Insanely light, packs up super tiny, fits slightly larger peopleComfortable, lots of good features, water reservoir includedComfortable, well-ventilated, adjustable torso length, included rain coverAdjustable torso length, very durable, great features and pocketsMoves with you, durable build, well-balanced load carry, good pockets and carry options
Cons Nearly no features, only one big pocket, super thin fabric, can feel contentsOn the heavy side, expensiveHeavy, ill-fitting hipbeltRuns a bit small, front stow pocket a bit smallNo hydration reservoir clip (loop only), not meant for downpours, very long torso
Bottom Line A bare-bones ultralight pack for those really dedicated to cutting ounces.A versatile daypack that can hold a lot of gear.This pack is loaded with features, and if it fits, you'll love it!A versatile, durable, and comfortable pack for the trail or town.A comfortable pack for even heavy loads over long distances with good balance and solid features.
Rating Categories Ultra-Sil Day Pack CamelBak Sequoia 22 Osprey Sirrus 24 Osprey Tempest 20 Black Diamond Nitro 22L
Comfort (25%)
10
0
3
10
0
9
10
0
8
10
0
7
10
0
7
Versatility (25%)
10
0
5
10
0
9
10
0
9
10
0
8
10
0
8
Weight (25%)
10
0
10
10
0
6
10
0
5
10
0
7
10
0
6
Ease Of Use (15%)
10
0
4
10
0
8
10
0
9
10
0
8
10
0
7
Durability (10%)
10
0
3
10
0
9
10
0
9
10
0
8
10
0
9
Specs Ultra-Sil Day Pack CamelBak Sequoia 22 Osprey Sirrus 24 Osprey Tempest 20 Black Diamond...
Weight (oz) 3 36 41 26 31
Volume/Capacity (liters) 20 22 24 20 22
Back Construction Lightweight nylon Ventilated back panel with molded pods Ventilated tensioned mesh AirScape backpanel; large spaced padding covered by large-holed mesh OpenAir backpanel; ridged foam covered by large mesh
Hydration None External hydration sleeve and 3L Crux reservoir included Internal hydration sleeve External hydration sleeve External hydration sleeve
Hipbelt No Yes Yes Yes Yes
Compartments 1 2 1 1 1
Rain Cover No No Yes No No
Additional pockets 0 7 5 8 5
Outside Carry Options Short daisy chain Trekking pole and ice axe attachments, side pocket, hip belt pockets (one zip), daisy chain, hydration hose clip Trekking pole attachment, ice axe loop, side strech pockets Lidlock helmet attachment, trekking pole quick-stow, large stretch front pocket, ice tool loop with bungee tie-off, side pockets, hip belt pockets, sunglasses shoulder stow, bike light loop Ice axe loops, dual 5-loop daisy chains, expandable side drink pockets, front stuff pocket, hip belt pocket, small zippered top pocket, four shoulder strap loops
Whistle No No Yes Yes Yes
Key Clip No Yes Yes Yes Yes
Materials 30D ripstop nylon 200D ripstop nylon, 400D plain-weave nylon 210D nylon body, 420D nylon bottom 70D x 100D nylon body, accent and bottom 420HD nylon packcloth 210D ripstop nylon, 210D Dobby Abrasion
Notable Features Packs into its own pocket, carabiner included Hydration bladder included, multiple pockets in both hip belts, internal storage pockets, exterior pocket felt-lined Integrated rain cover, ice axe loop, trekking pole attachment, adjustable back Helmet attachment, trekking pole quick-stow, sunglasses quick-stow, bike light loop, shoulder strap pocket, stowable ice axe loops Bike light loop, main zip opens all the way down, ReActiv shoulder straps connect to each other behind the waist and waist belt not attached to frame to facilitate twisting, front expandable pocket reinforced with internal structural foam panels

Our Analysis and Test Results

The Sea to Summit Ultra-Sil is the smallest, lightest daypack we reviewed. Sea to Summit used 30D ripstop nylon and cut out all padding to make this pack weigh just 2.7 ounces.

Performance Comparison



If you're a fan of the ultralight  the Ultra-Sil might be the right pack for you.
If you're a fan of the ultralight, the Ultra-Sil might be the right pack for you.

Comfort


For a pack that has literally no padding anywhere, this pack is… well, not comfortable unless you pack it right. It has no hip belt or load lifters or sternum strap, and the shoulder straps are padding-less. They do, however, have a very flat, ergonomic design that helps them to hold up this bag without digging into your shoulders. And though they claim this bag can hold 250x its own weight or over 40 pounds, we wouldn't recommend it for any length of time. The Ultra-Sil requires careful packing to stop from feeling every edge and corner from digging into your back. We found that this pack and other ultralight packs we tested are similar in overall comfort, though they take slightly different approaches to achieve that - rather than using some minimal padding in the shoulder straps, Sea to Summit chose a wide, ergonomic design with no padding.

These straps have no padding whatsoever  but their width helps distribute the weight across your shoulders.
These straps have no padding whatsoever, but their width helps distribute the weight across your shoulders.

Versatility


A lot of a pack's versatility hinges on the usefulness of its features, which the Ultra-Sil is lacking a lot of. This bag is just one zippered pocket and that's about it. There's a tiny loop on top you could clip something to and three fingers-worth of daisy chain on the bottom. If you really want to get inventive (and we bet you do, you ultralight enthusiast!), the tiny stuff pouch that ends up inside the pack could double as a little pocket for your keys. It also comes with a carabiner, which can then be used to attach something to the outside of the bag while it's in use. Other ultralight models retained a few extra pockets that we think make them more useful and versatile than this one.

One of the few features that this bag has - three loops of daisy chain near the bottom for clipping on  a bike light or attaching a whistle.
One of the few features that this bag has - three loops of daisy chain near the bottom for clipping on a bike light or attaching a whistle.

Weight


It's hard to beat a bag that only weighs 2.7 ounces (carabiner included). Even the other ultralight models we tested weigh more, though barely. This weight reduction does come at the cost of those extra features and key areas of padding. But if weight is paramount, the Ultra-Sil is the lightest we tested.

The Ultra-Sil (bottom right) is the smallest pack we reviewed.
The Ultra-Sil (bottom right) is the smallest pack we reviewed.

Ease of Use


The Ultra-Sil is extremely simple. At 20 liters of capacity, it has just one large compartment that zips wide open for easy access. It's also easy to lose one small item in just one large compartment, as we discovered. This pack is also without any zipper pulls, which cuts weight, but we found ourselves missing them, as the zipper tabs are incredibly short.

One area in which the Ultra-Sil has a slight advantage over other ultralight models we tested, is the size of person it can accommodate. With slightly longer shoulder straps, this pack is easier for taller and larger folks to wear.

Just one big pocket - though you could be crafty and use the stuff sack as a tiny pocket too!
Just one big pocket - though you could be crafty and use the stuff sack as a tiny pocket too!

Durability


Made of 30D ripstop nylon, this pack is the thinnest we tested. Even other ultralights are thicker (though marginally so). That being said, we had no actual issues with this bag during our months of testing. That doesn't mean we'd recommend it as your primary bag to hike through a thorny ecosystem though. If you like lightweight, but don't want to sacrifice quite so much in fabric durability, you might consider some of the other lightweight, simple packs we tested that only weigh a few ounces more.

30D ripstop nylon is quite thin  even on the reinforced shoulder straps.
30D ripstop nylon is quite thin, even on the reinforced shoulder straps.

Value


This pack is one of the cheapest we reviewed. For how versatile and portable it is, we think this is a great value. And hey, if you do rip an unfixable hole in that 30D nylon, replacing the whole bag at this price isn't quite so painful.

Turn any chance outing into an adventure by keeping an ultralight pack on your person.
Turn any chance outing into an adventure by keeping an ultralight pack on your person.

Conclusion


We appreciate the lengths Sea to Summit has gone to, to create this ultralight, super packable bag that just works. It's not one to load up with heavy or pointy objects or take on a long day out. Though we ultimately like the features included in slightly heavier ultralights just a little bit more, for an on-the-go bag, this one's pretty handy too.

The lightest pack we tested  the Ultra-Sil can come with you just about anywhere.
The lightest pack we tested, the Ultra-Sil can come with you just about anywhere.


Maggie Brandenburg