Thoroughly organise cycling in November briefly (12)

'thoroughly' is the definition.
(eg being thoroughly or convincingly defeated)

'organise cycling in november briefly' is the wordplay.
I cannot really understand how this works, but
'in' is within the answer.
'november' could be 'n' (phonetic alphabet: alpha, bravo, charlie etc.) and 'n' is found in the answer.
This may be the basis of clue (or it may be nonsense).