You wouldn't expect this bend on trip (8)
I believe the answer is:
windfall
'you wouldn't expect this' is the definition.
(a windfall is an unexpected source of money)
'bend on trip' is the wordplay.
'bend' becomes 'wind'.
'on' is a charade indicator (letters next to each other).
'trip' becomes 'fall' (fall is a kind of trip).
'wind'+'fall'='WINDFALL'
(Other definitions for windfall that I've seen before include "Apple blown from a tree" , "Bonus not expected" , "bonanza" , "unexpected blessing" , "Lucky bonus" .)