Synthetic Rope For Winching

Every four-wheeler at some point needs to use a winch. The type of rope used is vitally important. I suggest synthetic rope, even though it’s more expensive than steel and is susceptible to abrasions. It’s far stronger: A 3/8” synthetic rope of Amsteel-Blue has an average breaking strength of 19,600 pounds and a minimum breaking strength (MBS) of 17,600 pounds. The equivalent MBS in 3/8” steel rope is about 14,400 pounds.

Heavy Damaged

That added strength is crucial when winching is required. The line / cable in a winch rigging is generally the weakest point in the system. The best information I can find is that the safety margin (SM) for Amsteel-Blue is 5:1. Do the math. The working load limit (WLL) is recommended at 3900 pounds using the average Break Strength. We can exceed that using winches rated at 9,000; 9,500, 10,000 and 12,500 pounds. On the last wrap on the bare drum, the winch manufacture is guaranteeing its winch will pull that rating. So, at best on a straight line pull we have a safety margin of barely 2:1.

Do not use any recovery gear you do not know the rating. The formula for the relationship between Minimal Breaking Strength, Working Load Limit, and Safey Margin is:  Safety Margin = MBS / WLL. If you know any two you can calculate the one missing.

There are many products marketed to the recreational wheelers, that do not meet the OSHA standard for labeling sewed or attached to the item that provides the rating info. If by chance you acquire such a product, transfer the rating information from the packaging on to the product with a magic marker.

Check the rating on gear supplied by others for a recovery. If no rating, use your gear or walk away. Of course, explain the issue! “I have no way to know how strong this recovery gear is.”

Most common synthetic winch rope

The most popular brand of synthetic winch rope is AmSteel-Blue. Manufactured by Samson (, AmSteel is a 12-braid rope made with Dyneema® fiber.

Samson makes two versions of this rope of interest to us, Amsteel and AmSteel-Blue. Amsteel is made from Dyneema SK60 fiber, while AmSteel-Blue is constructed of the SK75 fiber. According to the manufacturer, SK60’s strength is about 20% lower than SK75’s, which is why I suggest using AmSteel-Blue.

One thing I really like about Samson is that they test their ropes with the splice in it. That’s “real world” testing, because nearly all applications require an eyelet loop splice. This is an industry standard that all quality synthetic rope manufactures should follow.

Incidentally, AmSteel-Blue isn’t always blue. It’s available in a variety of colors.

Another option for synthetic rope is Technora®. Manufactured by a subsidiary of Teijin Limited, Technora isn’t quite as strong as Amsteel-Blue. It is a Armid class of fiber. It has about 40% less strength then of the ultra-high-modulus polyethylene (UHMPE) class for Amsteel-Blue.

Overview of the supply chain for clarification

The different fibers are manufactured by several companies. DSM makes Dyneema. Technora is manufactured by Teijin.

Individual rope companies use these fibers to make 12 strand braded rope. Amsteel-Blue is woven into rope by Sampson Rope. Need a 600-foot reel? Purchase direct from Sampson.

Many, many companies buy the 600-ft reel and cut the winch lines and extension lines to length. They also add the eye splice, abrasion sleeve and end stopper.

Most winch manufacturers offer both synthetic rope and steel line. Request synthetic rope when you place your order.

You can also buy synthetic rope from various retailers. But request a length that is shorter than what you’d buy if considering steel rope. For example, if a winch would normally be loaded with 100 feet of steel rope, go with about 90 feet of synthetic. This is due to the abrasion sleeve that comes with the synthetic rope. Usually 3 to 5 feet long, that sleeve helps protect the rope from sharp and abrasive surfaces (rocks, gravel and such). You need to account for its thickness when reeling in the rope. Winch manufacturers take this into consideration when installing synthetic rope.

If purchasing from a retailer, an interesting suggestion but perhaps not practical, is to request a splice on both ends. That will save you a step if you have a short break by just swapping ends. It might be difficult to start the first wraps with a splice.

The Committee

At times, I feel it must have been a committee that made up the rules for synthetic rope use. Much like the California legislator put the southwest turn of California’s eastern border in the middle of Lake Taho without consulting a map.

The concern for the committee was winches of the day used the winch drum as a heat sink. No problem for steel wire but this could possibly damage synthetic line. Dyneema degrades at 150 degrees Fahrenheit. Today, more manufactures are moving the braking system (the source of the heat) outside the drum. Nevertheless, our recreational winches were not designed for lowering people or vehicles by powering out over the braking system. If you only power out 5 – 10 feet to reduce tension and de-rig, overheating should never be a problem.

In fact, a solution that frosts my butt, is using Technora on the first layer on the drum (Technora deforms at 500 degrees Fahrenheit) mated to AmSteel-Blue for the remainder. To match the strength of the AmSteel-Blue, the Technora needs to be a thicker diameter. This creates a real difficulty to “dress” the AmSteel-Blue tightly on the drum so you do not get “diving” when winching from a higher-level layer of wraps.  Diving is when the line splits or buries between lower wraps.  Sampson rope recommends a minimum of 100 to 200 pound of resistance on the rope (or more approaching the WLL if possible) when it is wound in to avoid diving.

The committee proclaimed “Synthetic rope should only be used with a HAWSE fairlead. Its smooth surface is more conducive to spooling the rope. When used on a roller fairlead, synthetic rope tends to get caught in the corners of the rollers.”

I have never seen or heard of a synthetic line ever being caught in the corner of a roller fairlead.
Many of us only use roller fairleads to reduce friction (heat) on the synthetic line. Pulling a winch line at an angle across a hawse fairlead under a load can degrade the line.

As shown in this picture, some vehicle Winch bumpers are designed with a recessed area to install a roller fairlead flush with the outside edge.  As a result of blindly following the rule “you must use a HAWSE fairlead with synthetic rope”, I see many situations where the roller fairlead has been replaced with a Hawse fairlead. The problem is, if the synthetic rope operates at any angle – anything but straight out from the vehicle – there’s a good possibility it will be cut by edges of the box. Go with a roller fairlead when the bumper has a recessed area for the Fairlead.

As stated above, a major drawback to synthetic rope is that it does not hold up well to abrasive or sharp surfaces.

Under tension, winch lines will cut on a sharp rock, a fairlead backing plate, and even part of a bumper. The abrasion sleeve helps a lot but can’t cover every possible hazard. But definitely use the sleeve. Position it over any rock or abrasive surface the rope is likely to encounter.

Never leave synthetic rope outside of the winch drum when not in use (say, attached to part of the bumper). The exposed rope can be cut easily while going through rough terrain. Always reel in the rope completely. A stopper type termination solves the issue.

Using a Pulley with Synthetic Rope

The Sampson Rope User Manual confirms the loss of strength when a synthetic rope is bent around a pulley. An 8:1 ratio should be considered the minimum ratio of the diameter of the pulley (big D) to the diameter of the rope (little d).

Data compiled by Donald F. Blair of Sierra Moreno Mercantile Co. and Richard Hildebrand of Yale Cordage shows a loss of 5 percent for an 8:1 ratio. The equivalent loss for steel line is about 17 percent.

How to maintain synthetic rope

As with any tool or piece of equipment, inspect the rope thoroughly before use. Be mindful of any breaks or tears. Because it’s a 12-braid line, one broken braid means a 1/12 reduction in the line’s strength. The rope should be replaced.

Synthetic rope develops tufts over time. (Similar to pilling on men’s shirt collars.) Samson offers an Inspection and Retirement Pocket Guide with a series of images depicting different levels of tufting. You can compare your rope’s condition to what’s on their card and decide whether the rope needs replacing. Sampson has an IPhone App which features inspections and retirement criteria. Download from the Apple Store.

Winch ropes get muddy and dirty. Rinse off the dirt with automotive car soap and water, and allow the rope to dry in a cool place. Never use a dryer as it may exceed the critical temperature. If the line is burned or scorched, you might have to retire it. Inspect that section thoroughly.

If a rope breaks, do not tie a knot. Doing so significantly reduces the strength of the rope at that point. (A significant crimp will, as well.) Consider using a remaining section of rope, or buy a new length of line. If there is sufficient undamaged rope, you could splice in an eye or two and use it as an extension. Heck, cut the remaining rope into sections and use it to practice making splices.

Additional suggestions for using synthetic rope

Synthetic rope is lightweight. A typical synthetic winch line might weigh 3 pounds. A comparable length of steel line could weigh as much as 25 pounds.

Pack one or two pieces of extension rope. I favor carrying two 50-foot lengths as opposed to one 100-footer. At some point during the winching process, you need to start shortening the line. It’s a lot easier to take out one 50-foot section than it is to figure out how to remove 100 feet – especially if you’re using a pulley.

Although synthetic winch rope is more expensive than steel – and susceptible to abrasions – it is a far better choice for winching. Consider switching to a synthetic rope for your winch.


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The 2024 schedule of clinics and adventures trips has been posted on the web site.

See the entire 2024 Schedule

May 2024

May 4, 2024 Getting Started Off-Road Driving – LA Area
May 5, 2024 Day 2 Getting Started Off-Road Driving – LA Area
May 4-5, 2024 Getting Started Two Day Package – LA Area
May 7, 2024 Utah Adventure
May 18, 2024 Winching Clinic – LA Area
May 19, 2024 Day 3 Putting It All Together – LA Area
May 25, 2024 Memorial Day Club Run

June 2024

June 1, 2024 Tire Repair and Hi Lift Mini Clinic – LA Area
June 15, 2024 Starting Rock Crawling

July 2024

July 5, 2024 Independence Day Club Run
July 13, 2024 Tire Repair and Hi Lift Mini Clinic – LA Area
July 20, 2024 Starting Rock Crawling

August 2024

August 12, 2024 Rubicon Adventure
August 24, 2024 Sand Dune Off-Road Driving – Oceano Dunes
August 25, 2024 Self Recovery Clinic – LA Area


I hope to see you on the trails!
Tom Severin, President Badlands Off Road Adventures, Inc.
4-Wheel Drive School
Make it Fun. Keep it Safe.

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