Massively beats cycling our trikes after vacation (5)
I believe the answer is:
routs
'massively beats' is the definition.
(to rout is to beat decisively)
'cycling our trikes after vacation' is the wordplay.
'cycling' indicates an anagram.
'after vacation' suggests removing the centre (the inside letters must vacate).
'trikes' with its middle taken out is 'ts'.
'our' with letters rearranged gives 'rou'.
'rou'+'ts'='ROUTS'
(Other definitions for routs that I've seen before include "Utterly defeats" , "Thoroughly defeats" , "Decisively defeats" , "drubbings" , "old parties" .)