Mountainsmith Zerk 40 vs Gregory Facet 45
Quick take: The Gregory Facet 45 carries more (45 vs 40 liters); the Mountainsmith Zerk 40 is lighter (2.13 vs 2.49 lbs).
Which one to buy
What carries the load differs between these two. The Gregory Facet 45 is the women's version of Gregory's Focal, with a tubular aluminum frame, an anti-barreling cross stay and FreeFloat suspended mesh that keeps air moving across your back. Gregory rates it to 35 lb. The Mountainsmith Zerk 40 relies on a removable frame sheet; Mountainsmith suggests up to 30 lb, and reviewers say it's comfortable up to about 20-25 lb and degrades past that.
The Zerk's advantage is flexibility. You can run it framed while your kit is heavier, then pull the sheet once your base weight drops, so one pack covers both. Its 40 L label may understate it. One review measured about 51 L, which matters when you compare it with packs labeled 50 L. The Extreema ripstop is tough and holds trail repairs, but it isn't waterproof, so use a liner. A canister rides vertically inside; reviewers say to skip the top straps because a canister slides off the side.
The Facet is the more complete pack for a woman who fits it. It comes in XS, S and M torso sizes, includes a rain cover and is covered by Gregory's lifetime warranty. The Zerk is one size for 16-21 in torsos, with Mountainsmith's lifetime warranty against defects. Once the load passes about 25 lb, the Facet's frame and mesh carry better. The Zerk earns its place only when you plan to drop the frame sheet as your kit gets lighter.
Mountainsmith Zerk 40
Suits a hiker of either sex who is cutting base weight and wants one pack that runs framed now and frameless later, with more room than its label says.
Gregory Facet 45
For women carrying up to 35 lb who want a real aluminum frame, a ventilated back and a rain cover in the box, sized from XS to M.
| Spec | Mountainsmith Zerk 40 | Gregory Facet 45 |
|---|---|---|
| Price | $230 | $230 |
| Rating | — | — |
| Type | Ultralight Pack | Ultralight Pack |
| Frame Type | Internal Frame | Internal Frame |
| Capacity | 40 L | 45 L |
| Weight | 2.13 lbs | 2.49 lbs |
| Max Load | 30 lbs suggested (up to 45 lbs) | 35 lbs (16 kg) |
| Torso Fit | One size, 16-21 in torso | Sized XS/S/M; S fits 16-18 in (41-46 cm) |
| Material | Robic nylon X-Grid Extreema ripstop with UTS coating | 100D HD 40% recycled nylon with 210D HD 45% recycled nylon, C0 DWR |
| Back Panel | Removable frame sheet | FreeFloat suspended ventilated mesh with ComfortCradle lower-back system |
| Adjustable torso | No | No |
| Ventilated back | No | Yes |
| Raincover included | No | Yes |
| Hipbelt pockets | Yes | Yes |
| Removable lid | No | No |
| Hydration sleeve | Yes | Yes |
| Fits BV500 bear can | Yes | No |
| Warranty | Mountainsmith lifetime warranty against material and workmanship defects; repair or replacement at Mountainsmith's discretion | Gregory lifetime warranty |
Pros & cons
Mountainsmith Zerk 40
- ✓The removable frame sheet means one pack covers both framed and frameless use.
- ✓One review measured about 51 L against the 40 L badge, where most packs here measure under.
- ✓Robic X-Grid Extreema ripstop (100D body, 210D base and back) is a tough woven fabric that repairs easily.
- ✓$230 is mid-range for the segment and below most cottage packs of similar volume.
- ✓Mountainsmith is a mainstream brand, so returns and support are simpler than cottage brands'.
- ✓1 lb 14 oz stripped (2 lb 2 oz full) is competitive with dedicated ultralight packs.
- ✓Hipbelt pockets included.
- ✓Widely available rather than made to order.
- ✗A removable frame sheet is less effective at load transfer than stays or a hoop.
- ✗No adjustable torso.
- ✗Not waterproof, unlike the laminate packs at this price.
- ✗Mountainsmith has less ultralight credibility than the cottage brands it competes with.
- ✗The 40 L badge understates the pack, which makes cross-shopping confusing.
- ✗Fewer configuration options than a made-to-order pack.
- ✗Limited presence on long trails, so fewer real-world reports.
Gregory Facet 45
- ✓2.49 lb with a full suspended-mesh back and a real frame; most packs this light give up one or the other.
- ✓A stated 35 lb ceiling, which is honest for a 100D pack and higher than many ultralight makers publish.
- ✓Tubular aluminum frame with a fiberglass anti-barreling cross stay and HDPE sheet, a real frame rather than a foam panel.
- ✓Rain cover included, in nylon taffeta.
- ✓ComfortCradle lower-back padding and a Polygiene odor treatment on the mesh.
- ✓Three torso sizes (XS, S, M) rather than a single women's fit.
- ✓Covered by Gregory's lifetime warranty.
- ✗No torso adjustment within a size, so the XS/S/M choice has to be right at purchase.
- ✗100D body fabric will show abrasion sooner than the 210D used on the base.
- ✗US pricing varies by retailer, from $229.95 to $249.95.
- ✗The Facet 55 has no sourced US price or weight.
- ✗Fixed lid, so the pack cannot be stripped for day use.
- ✗Gregory does not say whether a bear canister fits.
Mountainsmith Zerk 40 vs Gregory Facet 45: common questions
Which carries a heavier load, the Zerk 40 or the Facet 45?▾
The Facet 45. Gregory rates it to 35 lb on a tubular aluminum frame with a cross stay. Mountainsmith suggests up to 30 lb for the Zerk 40, and reviewers say its removable frame sheet is comfortable up to about 20-25 lb and degrades past that.
Is the Mountainsmith Zerk 40 really smaller than the 45 L Facet?▾
Not necessarily. One review measured about 51 L of real volume in the Zerk 40, well above its label, so in practice it may hold as much as the 45 L Facet or more.
Which of the two ships with a rain cover?▾
The Facet includes one in nylon taffeta. The Zerk's Extreema ripstop is tough but not waterproof, and it comes without a cover, so use a pack liner.