Now days when shopping for a winch, you have to decide wether your line will be the traditional steel cable or the new lightway synthetic rope.
The steel is for some a trusted natural old friend. Yes, it is heavy, but it takes a lot of abuse without issues. Although when it fails, and it eventually all do, could snap causing severe damages. Thats one of the reasons we all put weight on the lines, specially when using steel cables.
When we talk about synthetic rope, one could argue that Kevlar is a good option above steel. But when comparing the two, Kevlar tends to absorb 3.5% of its own weight in water while Dyneema absorbs no water, maintaining its performance in humid or wet conditions. Kevlar is considered 7 times stronger than steel, while Dyneema is 15 times stronger than steel, making it the world’s strongest fiber.
Keep in mind synthetic rope are susceptible to sun damage, so you need to keep it cover, specially during the summer. Steel’s worst enemy is rust. Newer synthetic lines are now UV resistance, but they still have a certain level of weakness on harsh weather compared to steel. Also in extreme hot temperatures, the fibers of synthetic lines will start to deteriorate.
Steel lines will always require gloves in order to handle it safely, and although gloves are recommended always when working with your winch, shackles or snatch block to protect your hands, a synthetic line is always less aggressive in your skin.
Steel is harder to repair on the trail compared to synthetic. Keep in mind, while mending rope or cable on the trail should only be done as a temporary fix, it’s something to consider.
Steel cable is deadly when it snaps at you at speed, but also synthetic lines could hurt somebody, so always be safe, stay away from the line’s direction, and always use a weight over the line to force it to go down in the event of failure.
Modern winches now use a synthetic line from Dyneema. Specifically the model sk75. Here is a short video that compares how this synthetic line compares to steel.
There is no right or wrong, it all depends how much you care about one aspect over the other. Weight, durability, maintenance, keep all these factors in mind when ready to buy your new line!