Climb and balance (5)
I believe the answer is:
scale
This clue is a double definition.
'climb' is the first definition.
(I know that scale is a more specific form of the action climb)
'balance' is the second definition.
(I've seen this in another clue)
'and' acts as a link.
(Other definitions for scale that I've seen before include "Relative extent as of laces" , "Deposit formed in a kettle or on teeth" , "An ordered series of units for measurement purposes" , "Relative magnitude" , "Climb; overlapping plate" .)