How to Choose Arborist Rope

What makes arborist rope different

Arborist rope is built for the specific demands of tree climbing: running over bark and friction savers, gripping friction hitches and devices, and holding up to sap, grit and daily abrasion. A climbing line is life-support equipment, so it must be approved for climbing by its manufacturer and meet the strength requirements in ANSI Z133.

There is no single best rope. The right arborist rope depends on whether you climb on a moving rope system or a stationary rope system, which hitch or device you use, and how you like a rope to handle. This guide covers the decisions in order. You can browse by type in our climbing rope section.

Static vs low-stretch rope

Arborist climbing lines are low-stretch or static. That is different from the dynamic ropes rock climbers use. Low-stretch lines give a little when loaded, which some climbers find comfortable on a moving rope system. Static lines stretch less, which makes ascending more efficient on a single rope because less of each step goes into stretching the rope.

Many SRS climbers prefer a firm static line, while many MRS climbers like a rope with a bit more give and a cover that holds a hitch well. Either way, a climbing line is not designed to catch a fall the way a dynamic rope is, so avoid any slack that could let you drop onto your system.

If you are just starting out, a lot of climbers recommend learning on a classic 16-strand line with a friction hitch. It teaches you how a hitch grabs and releases, it is forgiving of small mistakes in tending, and it wears well. Many climbers later add a firm static line for SRS once they move to mechanical devices.

16 strand vs 24 strand and other constructions

16-strand ropes have a cover of 16 thick strands over a core. They are durable, forgiving with friction hitches and a classic choice for moving rope climbing. Their cover texture can be less smooth in some mechanical devices.

24-strand ropes use more, finer strands, giving a smoother, rounder rope that tends to run well in mechanical devices and gives smooth hitch performance. Kernmantle static ropes have a tight cover over a load-bearing core and are common for SRS. You will also see 12-strand and double-braid lines, mostly used for rigging. Learn more in 16-strand and 24-strand climbing rope.

• 16 strand: durable, hitch-friendly, a classic MRS choice
• 24 strand: smooth, round, often device-friendly
• Kernmantle static: firm, low stretch, common for SRS
• Double braid: mainly for rigging, not climbing

Diameter and hardware compatibility

Diameter is where many climbers get into trouble. Most arborist climbing lines fall between about 11 mm and 13 mm. Every mechanical device, rope wrench, pulley and friction hitch has a range of rope diameters and constructions it works with, and the manufacturer lists them. A rope that is too thin can slip; a rope that is too fat can bind and be hard to tend.

Also note that two ropes with the same listed diameter can feel very different because of cover firmness and construction. Before you buy, read the instructions for your device and check the rope maker's compatibility notes. When in doubt, test the combination low to the ground with a qualified person before you climb on it.

Hitch cord matters too: it should be a smaller diameter than your climbing line and made from a material that handles the heat of descending. Ask the cord maker which climbing lines it pairs with.

Length, color and spliced eyes

A 150-foot rope covers most residential trees when climbing doubled. Single-rope climbers can often use a shorter line for the same tree, but many still buy 150 or 200 feet for flexibility. Longer ropes cost more and weigh more in the bag.

Bright colors and patterns make a rope easier to see against foliage and easier to tell apart from rigging lines on the ground. A sewn or spliced eye on one end saves tying a termination knot, keeps the end compact and lets it pass through some hardware more easily. Splices should be done by a qualified splicer and follow the rope maker's procedure.

Buy a little more rope than you think you need. A line that is just long enough leaves no room to cut out a damaged section, to work a wider spread or to reach the ground from a high tie-in. Make sure there is always a stopper knot or other means to keep the tail from passing through your system, and that your rope is long enough to reach the ground from the highest point you plan to tie in.

Matching rope to MRS and SRS

On a moving rope system, the rope runs over a branch union or through a friction saver, and you advance a hitch or device as you climb. The rope sees a lot of movement and heat at your hitch, so a durable cover and good hitch grip are priorities. Many MRS climbers like a slightly softer rope that their hitch bites into consistently.

On a stationary rope system, the rope is anchored and does not move over the tie-in point. You ascend with mechanical ascenders and descend with a device, so low stretch and consistent diameter matter most. A firmer static or kernmantle rope tends to give efficient ascents and predictable descents in SRS devices.

Many climbers end up owning both: a 16-strand line for MRS work and a static line for SRS access and work. If you can only buy one, choose based on the system you will use most and the device you will use with it. Our static climbing rope section covers popular SRS lines.

Inspection, care and retirement

Inspect your climbing line before every climb by running it through your hands. Look and feel for cuts, glazing, flat spots, lumps, core damage, chemical contamination and excessive fuzzing. Keep the rope in a bag, away from saws, fuel and sun when not in use, and wash it according to the manufacturer's instructions.

Retire a rope that has been cut, shows core damage, has been shock-loaded or contaminated, or has reached the end of its service life per the manufacturer. Never use a retired climbing line for rigging; cut it up so it cannot go back into service by mistake. See rope care and splicing for accessories.

Keep a simple rope log with the purchase date, first use and any notable events such as a hard shock load or contact with a saw. It makes retirement decisions easier and helps crews track which line is which when several look alike.

Common questions

What diameter arborist rope should I buy?

Most climbing lines are between about 11 mm and 13 mm. Pick the diameter your hitch, device and hardware are designed for, as listed by their manufacturers.

Is 16 strand or 24 strand rope better?

Neither is better for everyone. 16 strand is durable and hitch-friendly for moving rope climbing, while 24 strand is smoother and often works well with mechanical devices.

Can I use rigging rope for climbing?

No. Only use rope that the manufacturer has approved for climbing and that meets ANSI Z133 requirements as your climbing line.

How long does arborist rope last?

It depends on use, care and the manufacturer's guidance. Retire any rope that is cut, damaged, shock-loaded or contaminated.