A few years ago, I realized that I had enough parts on hand for a complete bike, so I threw it together. The rear hub was an old Bendix coaster.

It's fun to ride, and maybe I get a certain Luddite satisfaction from getting around on such a primitive machine. No surprise, it also happens to be my lightest bike.

But... I'm not a super strong rider, and there are hills in my area that I can barely climb at all on the bike. A few of those and it starts to get old. So I've still got my geared bikes for longer rides.