The parts. The material. Positioning of the chains and brakes. Handlebar position. Pedal tech. Many more bikes have batteries on them.
There’s a lot of changes to bikes that putting a 1900s bike to a modern one, and it’s the difference between comparing the Wright brothers plane and a modern personal plane today.
The bicycle hasn’t changed its basic design in 135 years.
Yes the frame is now welded but most bikes still have the cup and cone bearings that were the limitation of engineering in the 19th century.
I don’t know if this counts.
The parts. The material. Positioning of the chains and brakes. Handlebar position. Pedal tech. Many more bikes have batteries on them.
There’s a lot of changes to bikes that putting a 1900s bike to a modern one, and it’s the difference between comparing the Wright brothers plane and a modern personal plane today.