Troublemaker in bar friend sorted out (9)
I believe the answer is:
firebrand
'troublemaker' is the definition.
(I know that firebrand is a type of troublemaker)
'bar friend sorted out' is the wordplay.
'sorted out' is an anagram indicator.
'bar'+'friend'='barfriend'
'barfriend' anagrammed gives 'FIREBRAND'.
'in' is the link.
(Other definitions for firebrand that I've seen before include "One who stirs up trouble" , "Troublemaker" , "Energetic person often fomenting trouble" , "Agitator" , "Rabble-rouser" .)