When you call roadside assistance, like CoachNet, they will want to know IF you have a spare, either mounted on rim or unmounted. They will mount an unmounted tire for free or install your spare tire for free. They will also bring out a replacement tire, either new or used, depending on what is available. You will pay for that tire and sometimes will have no choice as to what brand of tire it is. If the tire that failed is under some kind of a warranty, you will have to find a place to store it in your coach until you can take it to a dealer to get reimbursed.