I suspect bicycles are one of those things that really seem obvious in retrospect but for some reason were invented well after the time when they were first feasible.
If you gave someone a bunch of gold, the ability to speak fluent Latin, and kicked them back into ancient Rome, I am sure they could commission the creation of a bicycle. It wouldn't be very good (no rubber for the wheels for starters, maybe replace that with several layers of leather? You might be able to make a leather belt-drive too.), but the general idea should have worked.
Another example is the phonograph. You can make a rudimentary phonograph with some very very basic clockwork, some wax, a needle, and a sheet of something taught and thin (I bet parchment would work fine.) The biggest issue would probably be figuring out how to present it without being burnt as a witch. But nobody did it until the late 19th century.
If you gave someone a bunch of gold, the ability to speak fluent Latin, and kicked them back into ancient Rome, I am sure they could commission the creation of a bicycle. It wouldn't be very good (no rubber for the wheels for starters, maybe replace that with several layers of leather? You might be able to make a leather belt-drive too.), but the general idea should have worked.
Another example is the phonograph. You can make a rudimentary phonograph with some very very basic clockwork, some wax, a needle, and a sheet of something taught and thin (I bet parchment would work fine.) The biggest issue would probably be figuring out how to present it without being burnt as a witch. But nobody did it until the late 19th century.