In my case it has led to a sudden urge to build a
parts bin weight weenie cycling vacation special.
Motivated by seeing mrs non-fixie enjoying
her little red RIH, I decided I too needed a sub-10kg bike for our next vacation trip (whenever that may be).
I didn't want to spend any money before being reasonably sure I was onto something, so for now I made do with what I had available: a scruffy Reynolds 531 frame with eyelets and room for fenders, Birmalux seatpost, CLB brakes and levers, Suntour Cyclone derailleurs, Bluemels mudguards, Stronglight cranks.
According to my cheap luggage scales it weighs exactly 10kg as pictured, which is a full kg lighter than any of my other 25" fendered bikes.
I just took it for a short test ride, and it feels rather nice. Light and responsive, without any of the nervousness I was half expecting. It corners beautifully. That narrow saddle needs to go, though.
The CLB brakes are a nice surprise. They are very light, but feel quite solid and the braking compares favorably to the MAFAC's I am used to.
The levers feel nice too, even without hoods.
There is still some work to do. To be able to add a bottle cage, bar tape and swap the too narrow Arius for a comfy Brooks I need to shave off at least another 200g ...