Unrefined cycling centre unknown (6)
I believe the answer is:
earthy
'unrefined' is the definition.
(I've seen this before)
'cycling centre unknown' is the wordplay.
I cannot really see how this works, but
'unknown' could be 'y' (algebra) and 'y' is located in the answer.
The remaining letters 'earth' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
(Other definitions for earthy that I've seen before include "Unenthusiastic" , "Head covering" , "Coarse like the soil" , "Resembling soil" , "Lusty, coarse" .)