Do they absolutely require it though? Looking at images of the first bicycles, they seem quite crude: https://upload.wikimedia.org/wikipedia/commons/8/8d/Draisi

Do they absolutely require it though? Looking at images of the first bicycles, they seem quite crude: https://upload.wikimedia.org/wikipedia/commons/8/8d/Draisine_or_Laufmaschine%2C_around_1820._Archetype_of_the_Bicycle._Pic_01.jpg https://upload.wikimedia.org/wikipedia/commons/8/8d/Draisine... The earliest ones don't even have pedals. The Romans had wheels and carts that seemed to work. It doesn't seem like a huge leap to put a human on them.