Tho only way I could accurately access this situation would be to make an on site inspection. That said, Yes the rope should be replaced as soon as possible. Has the problem just surfaced in the last few months? Or has it slowly been growing since the installation? I would love to see a couple more photos, one with a
bit longer section of the rope shown on both sides of the damage and one showing the rope and lock at the same time with the curtain in the 'on
spike" position, so I could see exactly where the damage is in relation to the curtain position. I would gather that the damage is shown with the curtain in the "down" position. What does the rope look like when the curtain is in the "other" position, i.e. all the way out? To be honest, unless the lock is defective with broken or jagged, sharp pieces in the cam, I find it difficult to imagine how it is causing the damage shown. It looks like a rope I replaced a few years ago and we found that one of the operators liked to run the
line at speed, then slam the brake on to stop the motion. In order for that to work for him, he had over tightened the adjusting screw on the brake. I'm not saying that is the case here, only that it resembles a similar incident a while ago. If you are in a position to do so,
and have a "qualified" person to do it, have that person completely secure the
arbor in an approved manner for the operation, remove the rope from the bottom of the
arbor and pull it through the lock. Now examine the interior of the lock for sharp or un-finished edges and surfaces. This may not solve your problem, but it is about the best I can do long distance.
As for the spiking method, I detest tape. It leaves goo on the rope, often slips along the rope or come off at the most inopportune time. Best way to
spike is to use a short length of brightly colored ribbon. Twist the
lay of the rope slightly open, using your hands or a rope
fid, and insert the ribbon so it sticks out about 1-2 inches on each side of the rope. The ribbon is easier to see coming even at high speed, and no, it does
not get caught in the pulleys or locks!
Stage Set X can be spiked with 1/4" ribbon or heavy knitting yarn, by using a large, rounded
point needle, one about 6-9 inches long and about the diameter of a 10d
nail with an eye, to work the casing apart and the ribbon or yarn through the outer casing.