Condition of cyclist (5)
I believe the answer is:
rider
I believe this clue is a double definition.
'condition' is the first definition.
(condition or specification added to a contract)
'cyclist' is the second definition.
(someone riding a bike)
'of' acts as a link.
(Other definitions for rider that I've seen before include "Appandix, codicil" , "Legal document's additional clause" , "Horseman or cyclist" , "knight" , "in the dressing room before the show?" .)