Staff with energy travelled by bike (4)
I believe the answer is:
rode
'travelled by bike' is the definition.
(I've seen this before)
'staff with energy' is the wordplay.
'staff' becomes 'rod' (I've seen this before).
'with' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mc2).
'rod'+'e'='RODE'
(Other definitions for rode that I've seen before include "Went by horse" , "did some travelling" , "Travelled on horse" , "Came by bike" , "Was passenger" .)