Apples and pears up ahead on floor above (8)
I believe the answer is:
upstairs
'floor above' is the definition.
(I've seen this before)
'apples and pears up ahead' is the wordplay.
'apples and pears' becomes 'stairs' (Cockney rhyming slang for 'stairs').
'ahead' is a charade indicator (letters next to each other) (some letters go in front of others).
'stairs' put after 'up' is 'UPSTAIRS'.
'on' is the link.
(Other definitions for upstairs that I've seen before include "On an upper floor" , "in one's mind ..." , "Away from servants" , "Mentally (colloquial)" , "On the next floor" .)