Best documented frame/bike designs

In the spirit of this forum (learning from each other), the idea of this thread is to collect links to bikes/frames whose design is particularly well documented with details about:

  • intended use case,
  • concept,
  • design choices incl. tube diameters and wall thicknesses, butting and the reasoning behind those decisions,
  • types of heat treatment
  • geometry,
  • detailed pictures
  • etc.

I have not seen this done better than by Fairlight Cycles:

Their All Road bike:

Their Gravel/Touring bike:

Their low trail Gravel/Touring bike designed for front loaded luggage:

Their XC MTB:

Particularly noteworthy are their dropouts which allow for flatmount and post mount calipers.