Cold beer needed after second climb (5)
I believe the answer is:
scale
'climb' is the definition.
(scaling is a kind of climbing)
'cold beer needed after second' is the wordplay.
'cold' becomes 'c' (eg on taps).
'beer' becomes 'ale' (I've seen this before).
'needed after' is a charade indicator (letters next to each other).
'second' becomes 's' (common abbreviation).
'c'+'ale'='cale'
'cale' put after 's' is 'SCALE'.
(Other definitions for scale that I've seen before include "little plate" , "Doh, re, me etc" , "Ratio between size and representation, on map say" , "Size ratio; skin flake" , "Tones rising maybe" .)