jerkoz, are the ropes breaking or cutting through? If the cords are breaking anywhere in their length and not from cutting on a edge of the rope that touches the mount, then you have some suspect rope. You can buy a better quality rope and try that. However, if the rope is being cut a little at a time, you need to fix that cutting edge first...or buy rope by the 100 rolls.
You can buy some stainless steel cable and attach that. But it will also scrap off finishes when it touches any metal part. The subtle vibrations will see to that. But that will work and be flexible is you buy a small gauge cable. Could even buy plastic covered steel cable of a light gauge and use that as well. Just remember the larger the gauge, the stiffer the cable. So for a trolling motor setup, keep the plastic covered cable on the light size to still be flexible. JMHO