Fractured rib racing with bikes on some French peninsula (8)
I believe the answer is:
brittany
'french peninsula' is the definition.
(Brittany is a peninsula in France)
'fractured rib racing with bikes on some' is the wordplay.
'fractured' is an anagram indicator.
'racing with bikes' becomes 'TT' (Isle of Man Tourist Trophy bike races).
'on' is a charade indicator (letters next to each other).
'some' becomes 'any' (similar in meaning).
'rib' is an anagram of 'bri'.
'bri'+'tt'+'any'='BRITTANY'
(Other definitions for brittany that I've seen before include "Tiny brat (anag) - region of France" , "Province of northwestern France" , "French region where Breton comes from" , "Bratty in northwestern France" , "Region of northwest France" .)