“However I will put gears on my bike when I get old and frail”
I’m already old and frail and I still prefer riding a rigid singlespeed. Old and stupid maybe?
Not stupid – sensible. Nothing keeps the whole body in such good condition as riding singlespeed, and it just happens without conscious thought or faff, just ride your bike.
There is a point where you start to weaken, but that’s why god invented the Sturmey-Archer 3 speed hub. 🙂
I’m old enough to remember the following phases of riding SS in the western world:
1. normal (fixed was also normal), derailleurs existed but were for those with pretensions to being fast, and actual racers, but most geared bikes had 3 speed hubs.
2. unusual
3. stupid
4. eccentric
5. niche
6. trendy (but proved too hard for the emaciated fashionistas)
7. just different
But all through those periods, single speed bikes have been the most common sort of bike made, and the most reliable. Folk are riding them long distances, up mountains, loading them with excessive weights, with minimal maintenance, and still managing without gears.