Flip-flop hubs are a thing: https://cyclistzone.com/what-is-a-flip-flop-hub/ https://cyclistzone.com/what-is-a-flip-flop-hub/ In my case (scroll back 35 years

Flip-flop hubs are a thing: https://cyclistzone.com/what-is-a-flip-flop-hub/ https://cyclistzone.com/what-is-a-flip-flop-hub/ In my case (scroll back 35 years), I would ride a fixed gear around the city, but change to the single-speed freewheel for Toronto's legendary "Doughnut Ride" that left Laird & Eglinton every weekend rain or shine, snow, sleet, or hail. In very olden times, riders would dismount and flip their wheels around in the middle of a Grand Tour before climbing the big mountain. But in contemporary riding, flip-flop hubs are just a convenience of sorts that make it easy to decide what gear you want to use for each ride, I have never flipped the wheel in the middle of a ride. p.s. I still have one bike with a flip-flop hub: It's a 24" trials bike, and while I run an 18t freewheel on the cranks, the flip-flop lets me choose between a 15t for pure trials work or a 12t for goofing around and having a tall enough gear to ride places, like on my local double black-diamond MTB trails.