A 100g waterproof shell that packs serious performance into your running vest
Overview
The Montane Minimus Nano Pull-On Jacket is one of the lightest waterproof layers in the world. Built for mountain running, fastpacking, and ultralight hiking, this minimalist smock offers Pertex® Shield protection, a no-fuss design, and a crazy low weight of just ~100g. With a race-ready silhouette and elite-level breathability, it’s a go-to shell for athletes who want maximum packability and minimum distraction.
Key Specifications
| Feature | Montane Minimus Nano Pull-On |
|---|---|
| Weight | ~100g (Unisex Medium) |
| Fabric | Pertex® Shield 2.5-layer |
| Waterproof Rating | 20,000 mm HH |
| Breathability Rating | 20,000 g/m²/24h MVTR |
| Fit | Slim/athletic |
| Pockets | 1 zipped chest pocket |
| Packability | Stows into its own pocket |
| Cuffs | Pre-elasticated (no Velcro) |
| Hood | Close-fitting, pre-elasticated |
| MSRP | £140 / $170 |
Materials & Construction
Built with Pertex® Shield, the Minimus Nano delivers legit waterproof performance for ultra-endurance scenarios. Despite its paper-thin handfeel, the fabric boasts:
- 20,000 mm hydrostatic head = excellent rain resistance
- 20,000 g/m²/24h breathability = keeps you cool under pressure
- Fully taped seams and durable water repellent (DWR) finish
- 2.5-layer construction with internal microprint to reduce clamminess
The shell is PFC-free and engineered for movement with minimal paneling and strategic articulation. Every gram is earned.
Fit & Comfort
The Minimus Nano runs true to size but in a close, race-cut silhouette. Think “athletic layer, not cafe cruiser.” It’s designed to sit over a single baselayer or thin mid—ideal for:
- Trail runners
- Race vest users
- Ultralight hikers
Features that aid movement:
- Dropped hem at the back for coverage while running
- Pre-elasticated cuffs and hood eliminate flappy adjustment points
- Quarter-length front zip aids temperature control
It’s not a lounging jacket—it’s an emergency shell and performance ally.
Real-World Performance
We tested the Minimus Nano across a series of spring trail runs in the Lake District and during summer mountain missions in Scotland.
Waterproofing
- Easily shrugged off moderate to heavy rain during 90-minute efforts
- Hood stayed in place during fast descents without strangling
- Chest pocket stowed a gel + key without bounce
Windproofing & Breathability
- Cut icy wind well on ridgelines
- Remained breathable at sustained pace—even on climbs
- Never felt boiled-in compared to heavier Gore-Tex shells
Packability
- Folds into its own zipped chest pocket
- Compresses to palm-size
- Tucks into a vest pocket or frame bag in seconds
This is a true throw-in-and-forget-it waterproof shell.
Use Case Scenarios
| Activity | Suitability Rating |
|---|---|
| Trail & fell running | ⭐⭐⭐⭐⭐ |
| Fastpacking & thru-hikes | ⭐⭐⭐⭐☆ |
| Race vest emergency shell | ⭐⭐⭐⭐⭐ |
| Road running (wet, windy) | ⭐⭐⭐⭐☆ |
| Alpine scrambling | ⭐⭐☆☆☆ |
Not designed for durability-heavy use (e.g. bushwhacking, pack-strapped scrambling), but excels in any fast, light, and wet scenario.
Compared to Similar Jackets
| Jacket | Montane Minimus Nano | Inov-8 Stormshell | Salomon Bonatti Trail WP |
|---|---|---|---|
| Weight | ~100g | ~175g | ~210g |
| Waterproof Rating | 20,000 mm | 20,000 mm | 10,000 mm |
| Breathability | 20,000 g/m²/24h | 20,000 g/m²/24h | Moderate |
| Fit | Close athletic | Relaxed | Trim athletic |
| Packability | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐☆ | ⭐⭐⭐ |
Verdict: The Minimus Nano is the most stripped-back and ultralight. It gives up features for weight but outperforms when you don’t want to notice your shell is there.
Pros & Cons
Pros
- ✔️ Incredibly lightweight and packable
- ✔️ Excellent waterproof and breathability stats
- ✔️ Race-ready fit—no excess bulk
- ✔️ Simplified design with no noisy Velcro
- ✔️ Packs into its own pocket
Cons
- ❌ Not built for abrasion or heavy use
- ❌ Lacks hand pockets or hem adjustment
- ❌ Pull-on style less convenient than full zip for some
- ❌ Limited warmth—purely an outer shell
Final Thoughts
The Montane Minimus Nano Pull-On is the kind of shell you barely notice until you need it—then it delivers. For trail runners, fastpackers, and alpine minimalists, it’s one of the smartest just-in-case rain solutions out there.
Sure, it trades off durability and adjustability for outright weight and packability, but if your priority is moving fast, light, and dry, this jacket has earned its stripes. Whether you’re chasing a PB, a summit, or a weather window, the Minimus Nano is a shell worth carrying—even when you don’t think you’ll need it.
