Spirit of those cycling? (5)
I believe the answer is:
ethos
'spirit' is the definition.
(thesaurus)
'those cycling?' is the wordplay.
'cycling?' indicates an anagram (I've seen 'cycling' mean this).
'those' with letters rearranged gives 'ETHOS'.
'of' is the link.
(Other definitions for ethos that I've seen before include "Those (anag.)" , "Character of a community or age" , "Spirit (of an age/culture)" , "Typical culture or attitudes" , "Moral significance" .)