hi! additional info is welcome here, but meanwhile, you may be interested in these

• Why didn't the Romans invent the bicycle?

• Did the Romans have the technical prowess to build functional bicycles?

some bicycle history

• What was necessary for the bicycle?

• How old is the concept of the "bicycle" or at least some form of mechanical transportation under your own power?

From an engineering point of view the materials required to build a bicycle weren't invented yet, specifically the steel used for the bearings, chain and sprockets.