“Changing the appearance and structure in a way affecting driving safety” is the definition of illegal modification. Awnings, larger batteries, dazzling lights, loudspeakers and lengthened e-bike frames all fall within the scope of the definition. Full story (in Chinese) via this link; read about Nanjing introduced as never before via this link.
Strict Investigation as to Illegal Modification of E-bikes Launched in Nanjing
