Gear for backward runner? (7)
I believe the answer is:
reverse
'gear' is the definition.
(I know that reverse is a type of gear)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for reverse that I've seen before include "Backtrack" , "Transpose" , "Upset" , "Countermand" , "Back (of a coin or medal)" .)