Arc'teryx Aerios 18 vs Arc'teryx Aerios 35
Quick take: The Arc'teryx Aerios 18 costs $70 less; the Arc'teryx Aerios 35 carries more (36 vs 18 liters); the Arc'teryx Aerios 18 is lighter (1.25 vs 2.56 lbs).
Which one to buy
Fit is the thing the extra $70 buys more than liters. The Aerios 18 comes in one pack size with a harness in two sizes, and its thermoformed AeroForm panel is shaped to a particular back profile, so it fits a narrower range of people than a foam or adjustable design. It is a try-before-you-buy pack. The Aerios 35 comes in three torso lengths (SRT, REG, TALL) with an interchangeable harness and three hipbelt sizes, which is rare at this volume. If the 18 doesn't sit right on you, the 35 is the Arc'teryx that can be made to.
Then comes the trip length. The 18 holds 18 L at 1.25 lbs and it is built for scrambling and fast mountain days, where its close, structured carry keeps it from shifting. The 35 is a roll-top that adds up to 10 L for an overnight, with a removable aluminum stay and a frame sheet that resists barreling under heavier loads. It's also the only Arc'teryx hiking pack above 18 L still sold, so there's no in-between size.
They share the gaps. Neither has hipbelt pockets or comes with a rain cover, and the 35 is roll-top only, so there's no lid pocket for the small stuff. For general day hiking, the 18's technical build is wasted and cheaper 18 L packs cover the same volume. The 18 is the purer tool for short technical days; it just has nowhere to go past them.
Arc'teryx Aerios 18
Best for scramblers and fast mountain days, provided you've tried it on and the one-size molded panel fits your back.
Arc'teryx Aerios 35
Worth the extra $70 if you need a sized fit or want one pack that stretches from big day hikes to a fast overnight.
| Spec | Arc'teryx Aerios 18 | Arc'teryx Aerios 35 |
|---|---|---|
| Price | $180 | $250 |
| Rating | 4.2★ (22) | — |
| Type | Daypack | Daypack |
| Frame Type | Internal Frame | Internal Frame |
| Capacity | 18 L | 36 L |
| Weight | 1.25 lbs | 2.56 lbs |
| Max Load | Not specified by the manufacturer | Not specified by the manufacturer |
| Torso Fit | REG pack size with an interchangeable harness in two sizes | Three torso sizes (SRT/REG/TALL) with interchangeable harness and three hipbelt sizes |
| Material | Body: 210D Hadron (94% nylon, 6% polyarylate LCP), FC0 DWR; 100D Cordura nylon accents | 210D Hadron nylon/polyarylate with FC0 DWR, 100D Cordura nylon 6,6 dobby contrast |
| Back Panel | AeroForm thermoformed back panel | AeroForm back panel |
| Adjustable torso | No | No |
| Ventilated back | Yes | Yes |
| Raincover included | No | No |
| Hipbelt pockets | No | No |
| Removable lid | No | No |
| Hydration sleeve | Yes | Yes |
| Fits BV500 bear can | No | No |
| Warranty | Arc'teryx limited warranty: defects in materials or workmanship for the practical lifetime of the product; wear and misuse repairs at a nominal charge | Arc'teryx limited warranty: defects in materials or workmanship for the practical lifetime of the product; wear and misuse repairs at a nominal charge |
Pros & cons
Arc'teryx Aerios 18
- ✓The AeroForm thermoformed panel holds its shape under load rather than compressing like foam.
- ✓210D Hadron, a nylon with a liquid-crystal polymer grid, is one of the most tear-resistant fabrics at this weight.
- ✓20 oz is light for a pack with a structured back panel.
- ✓Arc'teryx build quality and finishing are a genuine step above the rest of this group.
- ✓The close, structured fit suits scrambling where a loose pack shifts.
- ✓Liquid-crystal polymer is a high-modulus fibre normally reserved for far more expensive gear.
- ✓Strong resale value.
- ✓Backed by Arc'teryx's warranty and service network.
- ✗$180 for 18 L is expensive, and the Gregory Nano 18 covers the same volume for $80.
- ✗18 L limits it to short days or fast-moving trips.
- ✗No hipbelt pockets.
- ✗No published maximum load figure.
- ✗The thermoformed panel fits a narrower range of backs than an adjustable system.
- ✗No rain cover included.
- ✗One pack size, with the harness offered in two sizes.
- ✗Technical construction is wasted on general day hiking.
Arc'teryx Aerios 35
- ✓Three torso lengths plus an interchangeable harness with three hipbelt sizes, a fitting system few 35 L daypacks offer.
- ✓Hadron fabric blends nylon with polyarylate for tear strength beyond plain 210D, and the contrast panels are Cordura 6,6.
- ✓The 7000-series aluminum stay pulls out when the load is light, and the frame sheet resists barreling when it is not.
- ✓Roll-top closure adds up to 10 L for an overnight without a bigger pack.
- ✓FC0 DWR on the body fabric, and a reservoir-compatible main compartment.
- ✓A current-season record, so it will not be discontinued under you the way the Bora and Aerios 45 were.
- ✗$250 is $71 more than the REI Co-op Traverse 35, the obvious comparison at this volume.
- ✗Arc'teryx does not include a rain cover with it.
- ✗Arc'teryx publishes no maximum load.
- ✗Roll-top only, with no lid pocket on top.
- ✗No larger Aerios exists any more, so there is no room to grow within the line.
Arc'teryx Aerios 18 vs Arc'teryx Aerios 35: common questions
The Aerios 18 doesn't fit me well. Will the 35 be different?▾
Likely, because it's built to be fitted. The 35 comes in three torso lengths with an interchangeable harness and three hipbelt sizes, while the 18 comes in one pack size, with a two-size harness and a molded panel that suits a narrower range of backs.
Can the Aerios 35 handle an overnight?▾
That's what its roll-top is for: it adds up to 10 L over the nominal 36 L, and a removable aluminum stay and anti-barreling frame sheet help with a heavier load. Arc'teryx doesn't publish a maximum load.
Do either of them have hipbelt pockets?▾
No. On the 18 it is the one ergonomic gap in an otherwise polished pack, and the 35 doesn't have them either.