Gymnast needs this money in the bank (7)
I believe the answer is:
balance
I believe this clue is a double definition.
'gymnast needs this' is the first definition.
(a gymnast must have good balance)
'money in the bank' is the second definition.
(cash balance)
(Other definitions for balance that I've seen before include "Scale for weighing" , "Equilibrium or symmetry" , "It weighs - the remainder" , "Libra - amount in account" , "Cab lane (anag)" .)