Minibike was miserable (5)
I believe the answer is:
moped
I believe this is a double definition.
'minibike' is the first definition.
(moped is a kind of minibike)
'miserable' is the second definition.
(I've seen this before)
'was' is the link.
(Other definitions for moped that I've seen before include "Motor cycle -- sulked" , "moved aimlessly" , "Two-wheeled transport -- was in low spirits" , "Motorised bicycle" , "Light motorbike" .)