Passive vs Active Protection: The Fundamental Distinction
Traditional (trad) climbing protection divides into two fundamental categories: passive and active. Understanding the distinction shapes every gear purchase decision you'll make.
Passive protection holds itself in place mechanically through shape and wedging — nuts, hexes, tricams, and big bros. They have no moving parts, are lighter, cheaper, and more reliable in cracks with consistent width. Downside: they require finding placements where the shape of the crack matches the shape of the piece.
Active protection — spring-loaded camming devices (SLCDs, colloquially "cams" or "friends") — use spring-loaded lobes that expand to fill irregular cracks. They work in a much wider range of crack shapes and sizes. Cams are more versatile but heavier, more expensive, and have more failure modes if placed incorrectly.
Cams: Spring-Loaded Camming Devices Explained
Cams work by pushing their lobes outward against the sides of a crack. The cam angle — the angle between the lobe face and the stem — determines the friction coefficient and holding power. Cams with a 13.75-degree angle (the theoretical optimum) hold equally well whether the rock is wet or dry.
| BD C4 Size | Range (inches) | Range (cm) | Common Use |
|---|---|---|---|
| 0.3 | 0.4" – 0.7" | 1.0 – 1.8 cm | Finger cracks, seams |
| 0.5 | 0.5" – 0.9" | 1.3 – 2.3 cm | Thin hand cracks |
| 0.75 | 0.8" – 1.3" | 2.0 – 3.3 cm | Mid-hand cracks |
| 1 | 1.0" – 1.7" | 2.6 – 4.3 cm | Hand cracks (most common) |
| 2 | 1.5" – 2.5" | 3.8 – 6.4 cm | Wide hand / fist cracks |
| 3 | 2.1" – 3.6" | 5.3 – 9.1 cm | Fist to wide fist |
| 4 | 2.9" – 5.0" | 7.4 – 12.7 cm | Off-width (wide climbing) |
Most trad routes at moderate grades (5.7–5.10) require cams in the 0.5–3 range. Sizes 0.3 and below are specialty items for thin seams. Sizes 4 and above are for off-width terrain.
Nuts and Hexes: Passive Protection Fundamentals
Nuts (also called wired nuts, stoppers, or chocks) are tapered aluminum pieces threaded on a wire loop. They're placed by sliding them into a crack at the widest point that will pass, then tugging down to seat them in a constriction. The nut is held by mechanical compression against the sides of the constriction.
A standard nut set covers sizes from approximately 5mm to 40mm. Most sets number sizes 1–13 in small, medium, and large ranges. For beginners, sizes 4–10 (covering medium cracks) see the most use on moderate trad routes.
Hexes are larger passive pieces with a hexagonal cross-section that can be placed in both passive wedge mode and active camming mode. They fill the size range between nuts (up to ~35mm) and small cams (starting around 25mm), making them useful on routes with larger crack features.
Building Your First Trad Rack
A beginner trad rack should cover the range of crack sizes on the routes you plan to climb. For most moderate granite or sandstone routes in the US, the following provides excellent coverage:
- Nuts: 1 full set (sizes 1–13) + doubles in sizes 5–9
- Cams: BD C4 or equivalent in sizes 0.5, 0.75, 1, 2, 3 (doubles in 0.75 and 1 recommended)
- Quickdraws: 8–10 alpine draws (longer than sport draws for reducing rope drag)
- Slings: 4–6 shoulder-length (120cm) slings with locking carabiners for anchors
- Cordelette: 7m of 7mm cord for building anchors
- Nut tool: For removing stuck placements
Placement Basics: What Makes a Good Placement
A good trad placement holds in the direction of the expected load, is seated in a stable constriction or cam range, passes a firm tug test, and has no obvious failure modes (fragile rock, loose flakes, over-cammed lobes).
For nuts: the wire should exit perpendicular to the crack, the nut should be fully seated in the constriction (not teetering on the edge), and tugging the wire firmly should not dislodge it. For cams: lobes should contact the rock at the middle of their range (not fully retracted or fully extended), the stem should not be bent around a corner, and all lobes should touch the rock evenly.
Top Picks 2026
Black Diamond C4 Cam Set (0.5–3) EDITOR'S CHOICE
The C4 is the benchmark against which all other trad cams are measured. The double-axle design gives an unusually wide cam range, and the dyneema sling reduces weight without sacrificing durability. Sizes 0.5 through 3 in a 5-cam set covers 95% of moderate trad routes in North America. It's expensive to build a full rack at once — buy 2–3 sizes that match your local rock and expand over time.
~$75/cam Check Price on Amazon
Black Diamond Stopper Nut Set BEST VALUE
The BD Stopper set is the most widely used nut set in trad climbing. All 13 sizes ship on individual carabiners for easy racking. The tapered design holds well in both converging and parallel-sided cracks. At $55 for the full set, it's by far the most cost-effective trad gear purchase you can make — passive protection lasts decades.
Sources & Further Reading
- Rock and Ice Magazine — Gear Guide: Trad Protection (2025)
- Black Diamond Equipment — C4 Technical Documentation
- American Alpine Club — Trad Climbing Safety Guidelines
- Mountaineers Books — Rock Climbing: The AMGA Single Pitch Manual
- UIAA — Passive Protection Standard (EN 12270)
