First: If your helmet is less than 5 years old, then Cairns will replace it under warranty.
Second: Depending on how much "wire" is showing, the helmet can be repaired. I have repaired numerous helmets using a high temp. epoxy, molded into the contour of the helmet.
I have yet to have, or anyone else that has had me rebuild their helmet have a problem under extreme heat.
Some will say that fixing a leather helmet that is missing leather, unserviceable, but epoxy is stronger/longer lasting than leather. The only way you can tell with my repairs is the scroll work cannot be fixed/replaced.
Any questions, email ENG54INE@COMCAST.NET
I have pictures of other helmets that I have done.