Are there Open-source bikes? By 'open-source', I mean where people see the internals of each other's designs, and build on each other's works, as they do in science (or in 'open-source' software development).

I am a bit tired of 'black box, it's just magic' methods where I'm expected to simply believe in something, without being able to see exactly what that thing is and how it works.

I think it is very cool to reuse ideas and plans: so are there 'open-source' bike designs?
openbike.org (itself open) has inspired independent projects such as Jetrike (whose author makes plans available).
Expired patents may also count as open source because inventions must be fully disclosed. See for example a linked braking system from 1978, Calderazzo's US Patent #4102439, which makes it very difficult to flip yourself over the bars. (I read about this in Bicycling Science by David Gordon Wilson, Jim Papadopoulos, &amp; Frank Rowland Whitt.)