Well it was a youtube gimmick, just a proof that wood-on-wood isn't as high friction as people think.

But there were wooden bicycles without ball bearings in real-life history and they worked with the infrastructure they had. How well they worked is a different thing, but still it proves "no tech to build a bicycle" isn't the reason we waited for bicycles for thousands of years.

We had people jumping off towers with wooden wings for centuries before aeroplanes were made after all ;)

It would be perfectly possible for Romans to make bicycles from technological POV. Just wouldn't make sense because 2 slaves with some chair on sticks were cheaper.

BTW - first real world mass-produced bicycle added ball bearings after several years:

> On the new macadam paved boulevards of Paris it was easy riding, although initially still using what was essentially horse coach technology. It was still called "velocipede" in France, but in the United States, the machine was commonly called the "bone-shaker". Later improvements included solid rubber tires and ball bearings.

https://en.wikipedia.org/wiki/History_of_the_bicycle#1860s_a...

I completely agree with you, slaves were a major cultural and economic motivation behind technological innovation (or lack thereof). Consider the aforementioned example of the cotton gin, which used rather simple tech to replace slaves. This device was only invented when slavery became legally dubious. If Romans (or Greeks, or Egyptians, or the Chinese, etc) of antiquity could have opened their eyes beyond the use of slavery as a source of power, technological innovation would almost certainly have improved

To amplify number 2; I just spent a week in Rome; Cobblestone would seemingly destroy the fragility.

Anecdotally, on a bike ride recently, on a modern bike, hopping an inch curb snapped a chain.

Modern bikes are built yo tight tolerances for their purpose. Taking an inch curb in a mountain bike is nothing, taking it in an ultra weight optimized road bike is a different story.

Road bike chains aren't that delicate. It sounds to me like this person's chain was already old and near EOL. An inch curb on a road bike isn't that big a deal either, unless maybe it's a time-trial bike or something. The main problem with road bikes is that the wheels aren't as rugged as mountain bike wheels.

3. The test ride was down a hill. It is hard to judge without being there, but that is probably a 5% grade or so (see 6:54 in the video)