Sell part of bike, by the sound of it (6)
I believe the answer is:
peddle
'sell' is the definition.
(I know that peddle is a more specific form of sell)
'bike by the sound of it' is the wordplay.
'bike' becomes 'pedal' (synonyms).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'pedal' is a homophone of 'PEDDLE'.
'part of' acts as a link.
(Other definitions for peddle that I've seen before include "Sell from door to door" , "Sell (drugs or something hot?)" , "Travel around selling small items" , "Go from place to place selling" , "traffic" .)