In general a quick hot airflow is sufficient for shinking the pipe not affecting so much what is inside. Anyway, I do not feel confortable on using it as the isolator, particularly in your case, where due to the shaking of the byke, this may subject the assembly to a repetitive attrition; I consider it to be only a finishing jacket, being the electric isolation as a 'plus' since it is not uncommon for these pipes to tear with any salient sharp tip of the weld or wire, but if you take proper care, it may work pretty nice.