Police detained two teens, aged 16 and 19, after a 14-year-old boy was threatened with a knife and had his bike stolen in Newhall Car Park, in Newhall Street in the city centre, on January 16.
The arrests come after a West Midlands Police inquiry relating to a different knifepoint robbery when a teenager was threatened with a knife and his bike was stolen, in Rectory Park, Broomie Close, Sutton Coldfield, last August.
Ansel Causer, aged 19, from Sutton Coldfield, and the 16-year-old, who cannot be named due to his age, were remanded to appear before Birmingham Magistrates Court on January 18.
Jerimiah Hollinghead-Scott, aged 18, also of Sutton Coldfield, was also charged with two counts of robbery and knife possession the following day. He will appear in court at a later date.
The arrests followed an investigation led by the force's Gangs Team and Robbery Team in Birmingham.