Will a bear canister fit in the Unbound 40?

No — and that is a hard constraint, not a preference. Between the 40-liter volume and the geometry, canister country and long food carries are ruled out; if your trips include the Sierra, look at the Southwest 55 or a ULA instead.

Who is a 40-liter pack actually right for?

Hikers with a dialed sub-10-lb base weight and frequent resupplies — it is a fast-and-light tool, not a beginner pack. Converts say the 40L discipline improved their whole kit, but buyers who choose it for the aesthetic before their gear is dialed find it unforgiving.

How much weight can it carry?

HMG rates it to 40 lbs, though some owners find it carries best nearer 30 lbs, and winter kits and water-heavy desert stretches overwhelm it. Within its lane it carries meaningfully better than frameless rivals at similar weight, thanks to its two removable aluminum stays.

Is it actually waterproof?

The Dyneema-based construction is waterproof enough that owners skip pack liners and stop worrying about wet gear. The stretch front pocket even doubles as a place to dry a soaked tent on the move.

How is it different from the Southwest?

Two things: a stretch mesh front pocket instead of the Southwest's solid fabric (better for airing wet gear, worse in brush), and a bottom stash pocket that lets you grab a layer or snacks without stopping — the feature owners say they cannot go back from. Choose by terrain and hiking style.

Ultralight Pack

~$395

Hyperlite Mountain Gear

Hyperlite Mountain Gear Unbound 40

Name: Hyperlite Mountain Gear Unbound 40
Brand: Hyperlite Mountain Gear
Price: 395 USD
Availability: InStock

★4.8(4 reviews)

The Unbound 40 is HMG's fast-and-light pack for dialed kits, with a stretch front pocket and bottom pocket aimed at hikers who move all day and camp minimally. At 40 liters it suits sub-10-lb base weights and shorter resupply intervals.

Approx. price

~$395

Capacity

40 L

Weight

1.71 lbs

Best For

Dialed ultralighters with sub-10-lb base weights and frequent resupplies

Buy from Hyperlite Mountain Gear →

Price and availability on Hyperlite Mountain Gear’s site may differ.

Specifications

What do these specs mean? →

Type

Ultralight Pack

Frame Type

Internal Frame

Capacity

40 L

Weight

1.71 lbs

Max Recommended Load

Up to 40 lbs

Torso Fit

40L sized S/M/L/Tall, 55L XS-Tall: XS <15 in, S 15-17, M 17-19, L 19-21, Tall 21+ in

Material

Dyneema Woven Composite 3.9, 100D Dyneema Gridstop, Dyneema Stretch Mesh

Back Panel

Two contoured removable stays

Warranty

Guaranteed against manufacturing defects, no term stated

Raincover Included

Fits BV500 Bear Canister

Sizes Available

Capacity	Price	Weight
40 Lthis pack	$395	1.71 lbs
55 L	$420	1.81 lbs

Features

Hydration Sleeve

Pros

✓The bottom stash pocket — grab a layer or snacks without stopping — is the feature owners say they can't go back from.
✓Waterproof Dyneema construction means no pack liner and no wet-gear anxiety.
✓At 1.71 lbs with two removable stays it competes with frameless packs while carrying meaningfully better.
✓The stretch front pocket (unlike the Southwest's solid one) swallows a soaked tent for on-the-move drying.
✓Build quality matches its flagship siblings.
✓The 40L discipline forces a genuinely light kit, which converts say improved their whole system.
✓Clean compression lets it double as a big daypack or peak-bagging bag.
✓The white-and-black aesthetic carries the same HMG cachet.

Cons

✗40 liters plus no bear-canister fit rules out canister country and long food carries — a hard constraint, not a preference.
✗$395 for less volume than a $229 Flash 55 makes the per-liter math painful.
✗HMG rates it to 40 lbs, but some owners find it carries best nearer 30 lbs; winter or water-heavy trips overwhelm it.
✗Same clammy foam-on-back feel as every HMG.
✗Fixed sizes, minimal try-on options, and a boxy fit — the standard HMG sizing gamble.
✗The stretch pocket wears faster than the Southwest's solid fabric in brush.
✗It assumes an already-dialed kit; beginners who buy the aesthetic first find it unforgiving.

Common Questions

Compare the Hyperlite Mountain Gear Unbound 40

vs Bonfus Aerus 55L vs Hyperlite Mountain Gear Porter 55 vs Hyperlite Mountain Gear Waypoint 35

Related backpacks

Hyperlite Mountain Gear Porter 55

For hauling loads, HMG makes the Porter: the same roll-top Dyneema body as the Southwest and Windrider, but with a solid-fabric exterior and no mesh or front pocket, built to be strapped to and dragged through brush. It comes in four volumes from 40 to 85 L, and the two larger sizes are rated to 60 lbs.

55 L2.0 lbsSolid Dyneema exterior

Weight

2.0 lbs

Capacity

55 L

Frame

Internal Frame

Also in 40 L / 70 L / 85 L

Best for: Heavy or awkward loads in Dyneema: packrafting, hunting approaches, winter trips

View details

~$380

Ultralight Pack

Hyperlite Mountain Gear

Hyperlite Mountain Gear Waypoint 35

HMG's lightest framed pack is the Waypoint 35: a single aluminium stay in a 35 L laminate body with 6.5 L of stretch-mesh outside pockets and a padded, pocketed hipbelt that comes off. It fills the slot between the frameless Contour 35 and the two-stay Unbound 40.

35 L1.5 lbsSingle-stay frame

Weight

1.5 lbs

Capacity

35 L

Frame

Internal Frame

Best for: Sub-10 lb base weights that still want a stay and a real hipbelt

View details

~$420

Ultralight Pack

Hyperlite Mountain Gear

Hyperlite Mountain Gear Southwest 55

3.9(8)

The Southwest 55 is Hyperlite Mountain Gear's flagship all-rounder, built from waterproof Dyneema Woven Composite with solid woven pockets for brush country. It's the pack that made white Dyneema the visual signature of modern thru-hiking.

55 L1.93 lbsWaterproof Dyneema

Weight

1.93 lbs

Capacity

55 L

Frame

Internal Frame

Also in 40 L / 70 L

Best for: Thru-hikers who want near-waterproof simplicity and can pay for it

View details Hyperlite Mountain Gear

~$420

Ultralight Pack

Hyperlite Mountain Gear

Hyperlite Mountain Gear Windrider 55

The Windrider is the Southwest with a large mesh front pocket in place of solid Dyneema, so wet gear can drain and dry. The 2025 overhaul moved the line to Dyneema Woven Composite and widened the shoulder straps.

55 L1.94 lbsDyneema Woven Composite with mesh front pocket

Weight

1.94 lbs

Capacity

55 L

Frame

Internal Frame

Also in 40 L / 70 L

Best for: Thru-hikers who want external stowage that drains

View details Hyperlite Mountain Gear

~$420

Ultralight Pack

Hyperlite Mountain Gear

Hyperlite Mountain Gear Junction 55

The Junction sits between the Southwest and Windrider: a hybrid front pocket that is part solid Dyneema and part mesh, aiming to combine the Southwest's durability with the Windrider's drainage. Same 2025 fabric overhaul as the rest of the line.

55 L1.91 lbsDyneema Woven Composite with hybrid front pocket

Weight

1.91 lbs

Capacity

55 L

Frame

Internal Frame

Also in 40 L

Best for: Hikers who want a compromise between drainage and abrasion resistance

View details Hyperlite Mountain Gear

~$350

Ultralight Pack

Hyperlite Mountain Gear

Hyperlite Mountain Gear Contour 35

The Contour 35 is Hyperlite's frameless fast-and-light pack, and at 15.7 oz it is one of the few sub-pound packs on this site. Dyneema Composite Fabric makes it effectively waterproof at a weight woven fabrics cannot reach.

35 L0.98 lbsDCF with Dyneema Gridstop and stretch mesh

Weight

0.98 lbs

Capacity

35 L

Frame

Frameless

Best for: Fastpacking and low-base-weight trips where every ounce is counted

View details Hyperlite Mountain Gear

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