A soft one can be quietly downtrodden (5)
I believe the answer is:
pedal
'a soft one can' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for pedal that I've seen before include "Lever worked by foot" , "sustained note" , "part of organ" , "Power a bike" , "Of or relating to the feet" .)