When your crossbow’s serving goes bad you will need to use the rail lube that the manufacturer recommends for your bow. If you do not have any lube on hand you will need to take a trip to your local pro-shop. The recommended lube can extend the serving life o your bow. If a visit to the pro-shop is not doable you can always use dental floss to replace the worn servings.
Best to pack some dental floss on your hunting trip. While the dental floss is a quick fix be sure to remember the ix is only temporary.
Another reason for finding your crossbows serving is warring or unraveling could possibly be due to puling up on one side of the string a little harder than the other an therefore the cocking device will not be able to contact the serving at the true center. This is where buying a rope cocker and using it with your crossbow will come in handy. The rope cocker will allow you to pull evenly.