Following pictures describe proper loop cording of one hole nunchakus
This is most reliable cording I know. All my daily practicing nunchakus are corded this way and were never repaired. I can guarantee minimum 5 years of intense training before you will even start thinking of replacing the cord.
This is replaceable cording. Loop can be easily taken off with pliers.
Assembling/disassembling Loop Nunchakus (Airport connection)
Other Cording Types
Classic 3 holes nunchaku (Okinawa) cording
Classic 2 holes nunchaku cording