It’s true – all dynamic kernmantle ropes are built similarly: every company starts with the same sheath and core nylons, employs a tried-and-true braid and weave, and uses a heat-setting process that gives the rope dynamic properties. And all of these ropes have the same purpose: to catch a fall.

But they’re not created equally. Every rope company has a different definition of performance. As a result, different ropes undergo unique tweaks, many of them proprietary, at every step of the process. The tweaks range from the simple (number of nylon strands that comprise the core) to the complex (dry-treating fibers to offer ideal lubrication for weaving). To achieve a specific set of performance criteria – getting the elongation rating to hit 33 percent while still catching well and being waterproof, for example – attention must be given at every step.

Each manufacturer has a vision of what makes a rope great. This means, no matter the diameter, two ropes from the same company will likely have a similar feel – in handling, catching power, dry treatment – because that company’s general performance criteria, and processes to achieve those results, are unique.

Beginner or pro, knowing more about how rope companies differ may help you choose the right cord to improve your game. I recently spoke with the following rope manufacturers to discuss nuances beneath the sheath.

Bluewater
Goal: To build a consistent rope that maximizes energy absorption.
Process: “It all comes down to process control,” said Bluewater owner Dick Newell. This includes testing every batch of raw materials as well as finished products to ensure quality and consistency. Complete control of the twisting, braiding, and finishing operations guarantees that every rope has the same characteristics, regardless of when they were manufactured, Newell said.
Dick’s Picks: Accelerator 10.5, Eliminator 10.2

Mammut
Goal: To build a balanced rope that has a “good blend of properties that will handle well, last a long time over the life of the rope,” said Dave Furman, hard good category manager at Mammut.
Process: A chemical that “Teflonizes” core fibers is applied during heat treatment. This makes core fibers more slippery, generating less friction during falls and extending the life of a lightweight rope. For consistency, Mammut tests every batch of ropes they produce. Dave recommends comparing technical specs, like true diameter and weight, before buying a rope.
Dave’s Picks: Tusk 9.8, Genesis half ropes 8.5

New England Ropes
Goal: To produce a stiff, durable rope that gives controlled falls and has consistent impact ratings over the rope’s life.
Process: New England Ropes uses mathematical models to develop ideal impact curves (force over time) that maximize long-term consistency. Then they build ropes to match those curves. “It’s not the number itself of the impact rating that’s important,” said Dan Birch, the company’s market manager. A stretchy rope that performs well in the UIAA tests, he said, might absorb a high initial impact force but then exponentially decrease in force held and therefore durability. Also, fine-weave sheath patterns on their Glider Series decrease rope drag by up to 18 percent, so the rope feels lighter while leading.
Dan’s Picks: Glider 10.2, Pinnacle 9.5

Petzl
Goal: To produce ropes extremely consistent in dynamic properties and durability.
Process: Core fibers at Petzl are heat-treated and shrunk evenly, and ropes are tested for consistency at every step. Similarly, with their proprietary dry treatment, they “aim for a consistent amount applied to each strand,” said Eric Wynn, rope product manager for Petzl. “Every fiber is individually treated, both core and sheath.” Petzl ropes are butterfly coiled at the factory to make it easier to uncoil when brand new. This process also helps eliminate kinking.
Eric’s Picks: Fuse 9.4, Nomad 9.8

PMI
Goal: To build a consistent, durable, and supple rope that needs no breaking in.
Process: PMI carefully selects yarn to ensure consistency across batches. Sheath yarn (dry treated even for their non-dry ropes) is woven in a special braiding process designed to give “a supple hand right out of the factory coil,” said Scott Park, sales manager for PMI. The company also is scrupulous about watching retailers’ supply. “We don’t want to see any outdated ropes on the shelf,” Park said. “That helps ensure longevity of every rope in the customer’s hand.”
Scott’s Picks: Spire 10.2, Arete 9.4

Sterling
Goal: “We try to strike a balance between durability, soft catch, and reasonable elongation,” said John Branagan, Sterling’s outdoor products manager.
Process: Sterling focuses on elongation, primarily determined from the number of nylon yarn strands in each core, their TPI (turns per inch; also called “twist level”) and the computerized thermal balance of the yarn during the heat-setting process. Sterling also works with a recycling partner to reformulate their raw material – and your old ropes – into plastic for other industries. [Ropes should be sent to 26 Morin Street, Biddeford, ME 04005 and marked clearly for the rope recycling program.]
John’s Picks: Velocity 9.8, Marathon Pro 10.1

Because there’s often no chance to “test drive” a rope before buying, the online community can be a good resource in discovering which rope is best for you. Remember that every pro usually comes with a con. The advantages listed above are contestable – and are debated heavily within the industry. Dan Birch at New England Ropes recommends thinking about rope manufacturing as “80 percent science and 20 percent art.”