Unusual sort of bar rider jumped (4,4)
I believe the answer is:
rare bird
'unusual sort' is the definition.
(I've seen this in another clue)
'bar rider jumped' is the wordplay.
'jumped' indicates anagramming the letters (I've seen 'jumping' mean this).
'bar'+'rider'='barrider'
'barrider' is an anagram of 'RARE BIRD'.
'of' is the link.
(Other definitions for rare bird that I've seen before include "Unusual type" , "the talking point of twitchers?" , "Exceptional person" , "Exceptional thing" .)