Joe’s first design was a piece of art, this second Joe’s design is definitely a piece of machinery, with its sharp angles and CNC look. Personally I do not find it aesthetically pleasing, the sharp angles look alarmingly like stress-raisers to me and I dislike the way the parallelogram spring sticks out at one end.
Technically it has a single sprung pivot, with the guide pulley offset from the sprung pivot by about 18mm. Both pulleys use sealed bearings. It looks as though you could completely disassemble it, but you would have fun playing with tiny circlips. It is light but not earth-shatteringly so.
Beautifully made, but slightly underwhelming.