Learn This: Extension 102

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Every beginning trad climber learns the basics of “extension”—using slings or quickdraws to create more space between the rope and a piece of gear. (Check out Extension Basics for a quick refresher course.) There are three main reasons behind extension—reducing rope drag, keeping pro in its proper place, and preventing the rope from running over sharp edges—and there are plenty of subtleties that can make you a fast, smooth, and expert extender. These tips aren’t just for trad climbers. Bolt-clippers can improve their safety and sending success with these techniques as well.

The Tools

Quickdraws, single-length slings (sometimes called full-length), double-length slings, and carabiners are essential parts of any trad climber’s standard kit. (You’ll also hear slings called runners, which is short for “running belay,” meaning any protection point between stationary belay stances.) With a combination of these four main components, you can extend pieces from three inches to four feet.

Quickdraws are the go-to tool for clipping fixed gear and making short extensions. Draws vary widely in cosmetics and price, but more importantly they vary in their designated purpose. For sport climbing, you want full-size, wear-resistant biners on stiff, beefy slings (think Petzl Express or Trango Smooth draw). For trad, however, much lighter draws work better—featherweight biners on thin, supple slings to reduce bulk and weight and provide a more flexible attachment to nuts (think Black Diamond Oz). For sport and trad, carry at least two different lengths of draws, so you have options if a bolt or gear placement pinches the rope against an edge or leaves a carabiner levering over it. The number of bolts (plus two for the anchor and at least one extra for insurance) will determine how many draws to carry for a sport route, but on trad routes, six to eight dedicated draws is typically about right. If there are any “must-hold” clips (e.g., the first bolt or a piece above a ledge) consider putting a lightweight locker on the rope end of the draw.

Single-length slings should be the mainstay of your sling collection. They’re sized to fit neatly over one shoulder and give approximately 24 inches of extension when clipped with a biner on each end. Standard slings are 48-inch sewn loops, but individual runners can vary a few inches, to better fit larger- or smaller-chested climbers. For versatility, try to mix it up a bit when racking—a few inches of difference in length can come in handy when trying to equalize two placements, and different materials have different uses. Sewn 3/8” (or 10mm) tape is a good standard width for slings, but consider hand-tying a few with a simple water knot, so they can be undone for threading bolts or pitons during unplanned rappels. For even more versatility, tie these slings with 5 to 7mm cord, so they can double as prusiks if necessary or be used as pro when threading narrow holes or slinging chickenheads and knobs. (If your tied slings have been used for a while, make sure you can still get the knots undone before you leave the ground.) Bring at least six single-length slings total, and up to twice that for complex terrain with lengthy pitches, or on long routes if an unplanned retreat seems possible.

Double-length slings provide a whopping four feet of extension and are more useful for rigging and anchors than for extending a single piece of pro. If you extend a piece four feet, you’ve added eight feet to your fall, which is a bit much for safe travel on most blocky trad terrain. However, doubles come into their own when building belay anchors, when slinging cliff-top trees, as mini cordelettes for equalizing placements, and for using in rap anchors (or when creating a mini belay seat, see p. 41). Carry two or three double-length slings, more if you might have to bail.

Carabiners that are loose and not designated for a certain piece of gear are crucial, so carry an assortment to employ during extension. These can be carried a variety of ways: Some people prefer to stack them in sets of five on a gear sling or loop of their harness (clip one biner to the sling or loop and the other biners to that first one), while others prefer to clip a single biner to each sling over the shoulder.

The Rabbit Runner

Learn This: Extension 102

An efficient alternative to the double-length sling is the Rabbit Runner, a 1970s Bill Forrest (legendary Colorado climber who made several major innovations in climbing equipment) design that’s still available from Metolius. A Rabbit uses the same amount of material as a single-length sling, but instead of being sewn into a closed loop, each end has its own small loop to clip a carabiner. Thus, you can use a Rabbit as a normal single-length sling, by clipping it doubled, or extend it single-strand for twice as much extension. Just adding one of these to your standard rack can greatly increase your placement, anchor, and rapping possibilities.

Don’t Over- or Under-Extend

Learn This: Extension 102

Below roofs, before and after significant traverses, placements deep inside a wide crack—all of these situations demand full-length slings. Cams placed in a splitter crack seldom even need a quickdraw, but delicate nut placements in that same situation are best fitted with a flexible draw to keep the rope from dislodging the nut. When learning, I used long runners on almost everything. Now, I use them sparingly. Look below and above your chosen placement to imagine the rope’s path after you clip your piece with a draw or a sling. Is the extension serving a purpose? If not, don’t extend. Adding four feet to your potential fall might mean the difference between a harmless slip and an injury. Sometimes you’ll place a “critical” sling—a single point that protects the second on a traverse or keeps the rope from a razor-sharp edge. In these cases, use two opposite and opposed biners or a locker on the rope, and double up the pro if possible.

Sling Configurations

Learn This: Extension 102

Most of the time you can just clip your chosen sling to the piece of gear and the rope (fig. 6), but there are a few other options if you need to gain or lose a few more inches. If you’re short on biners, try girth-hitching a cam’s sling (fig. 5, but don’t do this with a wired nut; the cinching action of the girth-hitch can cut the sling in a fall). By doubling the runner through the cam’s sling (fig. 3, this works for wires, too) you’ll shorten the extension. Pick just the extension you need and no more. For long routes, speed of placement and re-racking is important. To move fast, add a few extra biners to the rack and nix all girth-hitching. Likewise, when quickdrawing a cam, leave the cam’s biner on the gear. It wastes a biner, but saves time when the gear is re-racked. Small savings add up over the course of a dozen pitches. A standby for rigging full-length slings is the "alpine quickdraw." If you end up with a wrap around one of the biners, take the time to fix it. The wrap can work its way onto the gate, increasing the chances of cross-loading or unclipping. You can improvise a draw by clipping biners to both ends of a wired nut or corded pro, such as hexes.


How many times have you needed a sling, only to find it inaccessibly draped over your wedged shoulder or hopelessly tangled with six other slings and biners? Rack smart to avoid such bondage. The alpine draw setup works well for a few of your full-length slings, but carrying them all that way consumes valuable harness space. The simplest option is over one shoulder—in my opinion, best done without biners, which promote tangles. Another alternative is to carry one “runner runner” over your shoulder, then double the rest of your single-length runners over that runner so they hang on your side, clipping both ends of each hanging runner with a carabiner. To deploy one-handed, simply unclip from one strand and pull. (Check out Learn This: The Runner-Runner a quick demo.) When swapping leads with a partner, I’ll often rack all the quickdraws on a dedicated shoulder sling to speed up changeovers. Since I seldom use my double-length slings except at belays, I carry them tripled, knotted, and clipped to a biner on a rear harness loop.