> As for ball bearings these are incremental improvements not a necessity (see horse chariots and carriages with wheels used for millenia before we had ball bearings). For another example see medieval wooden windmills - all cogs and bearings made from wood with some animal fat and skin for bushings and lubrication - worked well enough for centuries.
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>> Anyone accustomed to modern practice finds it hard to believe that wood-on-wood could function as a bearing at all. This primitive arrangement was improved in a few cases by the addition of a leather bushing. Lubrication in the form of animal fat or tallow is known to have been used, although the exact composition has not been determined.
You'll notice that your examples involve a lot of power driving the mechanism - a team or horses or a windmill can overcome the kind of friction a wood-on-leather bearing implies. If you've ever ridden a bicycle where the fender was rubbing on the wheel, you'll know that human power is much more limited.
1. The bike looks super wobbly and seems like it takes a lot of effort to just make it function properly. Yes, it is an example of a wooden bicycle, but it is not an example of a useful wooden bicycle. It seems like it probably has a pretty short working life and low speed. In short, it's worse than just running.
2. The bike is being run on a paved road. All of my earlier criticisms get magnified by the stress of taking the bike off road. Yes, dirt roads are a thing. No, they are not nearly as smooth as asphalt. Also, much like carts, a bicycle like that would start to put ruts in a dirt road.
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.
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
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.
It's not just wood. It's thin wood glued together .. but yes .. a wooden bike is possible .. but there is a reason why nobody does use it in everyday life.
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>> Anyone accustomed to modern practice finds it hard to believe that wood-on-wood could function as a bearing at all. This primitive arrangement was improved in a few cases by the addition of a leather bushing. Lubrication in the form of animal fat or tallow is known to have been used, although the exact composition has not been determined.
You'll notice that your examples involve a lot of power driving the mechanism - a team or horses or a windmill can overcome the kind of friction a wood-on-leather bearing implies. If you've ever ridden a bicycle where the fender was rubbing on the wheel, you'll know that human power is much more limited.