Carabiner Size
Carabiners come in a variety of sizes. Large ‘biners are typically easier to handle and easier to clip (they have larger gate openings), and they can hold more gear inside. They are commonly used with belay and rappel devices. Smaller ‘biners are lighter and take up less room on your rack, but they can be harder to clip.
Gate open clearance, provided in millimeters, is something you may want to pay attention to when looking at the size of a carabiner. This number refers to the width that the gate can open, plus the depth and shape of the bottom of the carabiner below the gate. Generally the smaller the carabiner, the less clearance it offers.
Too little gate-open clearance may lead to your finger getting stuck between the gate and the carabiner body while clipping; too deep a clearance can also make the carabiner difficult to clip. An ideal amount makes clipping the ‘biner easy.
Carabiner Weight
In general, the less weight you carry with you as you climb, the better. But lighter carabiners are not always best. Superlight carabiners are often smaller, which can make them harder to use when you’re clipping the rope or a bolt. Also, lightweight carabiners often use narrower rod stock, which can mean lower gate-open strengths and shorter lifespans. Narrow ‘biners can also cause more rope wear, since the narrow ends can act like edges, biting into your weighted rope as it slides past.
Carabiner Strength
Carabiners are rated for strength in three directions: lengthwise (major axis), sideways (minor axis) and while open (major axis open or “gate open”). These ratings are typically marked on the spine of the carabinerAll climbing carabiners pass UIAA and CE standards, which means they are plenty strong enough as long as you use them correctly. Gate-open strength and minor-axis strength are where you see the most variation.
Here’s how you might use strength ratings: If you’ve narrowed your search to a few different carabiners that will work well for your style of climbing, look at the strength ratings as one of the final decision points. If one carabiner provides everything you need and is stronger than the others, then you might as well go with that one. Keep in mind that smaller and lighter carabiners are generally weaker than bigger, heavier ones, but not always.
A note about gate lash: The dynamics of just about any climbing fall can cause gate lash, which can reduce a ‘biner’s overall strength to its open-gate strength, creating a higher likelihood that the carabiner could break. It can occur when:
- A gate’s inertia overcomes the spring tension holding it in place
- A gate collides with another object
To protect yourself against this type of carabiner failure, choose carabiners with specific gate designs (such as a wiregate) and/or stiff spring tensions. You can also opt for carabiners with locking gates and/or high gate-open strengths (REI provides both gate-closed and gate-open strength ratings on the product page Specs tab). Ask an experienced REI salesperson for recommendations.
Your safety is your responsibility. No article or video can replace proper instruction and experience. Make sure you practice proper techniques and safety guidelines before you climb.