LOW Profile Nylon Traveller Car With Lacing Eye

We have these fitted to our sliding doors on our Broom flybridge motor cruiser. They are fine when newly fitted but despite cleaning the tracks they run on if any dust or dirt gets on the track despite constant cleaning and lightly spraying with PTFE the travellers begin to break up. The plastic outer cover becomes slightly open at the ends and the roller bearings begin to fall out over time. To replace the whole system is extremely expensive so we unfortunately have to tolerate changing them periodically. We are constantly on the lookout for a more reliable system.