Henry had twelve gears; I used two of them. He had two Biopace chainrings in the front and a six-sprocket cassette in the rear. The Biopace chainrings were a bit egg shaped and meant to maximize the number of gear teeth meeting chain links during one’s downstroke — I think that was the idea anyway. Regardless, the front derailleur barely moved and the rear wasn’t much better. The shift levers were attached to the downtube, and the exposed wires ran down the underside of the frame around the bottom bracket. The derailleurs needed work when I bought the bike, and it would be a while before they got the attention they deserved. I could only downshift the front chainrings and most of the time tried my best to not bump that lever. The rear could actually move back and forth but alignment was terrible. Sprockets one and three were my dogs. Two would slip into one or three, and four through six could hold when I physically held the lever, but the sound was awful. There are worse bicycle sounds - screeching brake pads on rims, for example. The pain of a grinding gear change is partly existential; it’s the sound of failure.
When Henry’s rear wheel got stolen a couple of years later, I was inspired by necessity to never have a quick-release element on any bike I park in a city ever again, and more importantly to improve my bicycle maintenance game. Henry got a complete overhaul. I tuned up the derailleurs as best I could. Sprocket two continued to slip though, and I had the new problem where I could over shift. When downshifting to sprocket six - the big boy - the derailleur could go too far throwing my chain over the cassette into the spokes. That’s a bad problem. Between these less-than-ideal conditions and the force of habit, I kept using the same two gears for 98% of all riding applications.
In New York City, you don’t need a lot of gears. Our hills aren’t so bad. Mostly they’re bridges. If you can do without multiple speeds, a world of bike joy opens to you. The single greatest benefit to riding a single-speed bike is the maintenance. The cables and moving parts required to shift gears are some of the most delicate, futzy, pain-in-the-ass parts of bicycle. When you switch to a single speed, not only do you eliminate the fail factor of those futzy parts, the drivetrain you’re replacing them with can be more robust. You don’t need a long skinny chain capable of slipping up and down a big cassette; you can ride a KMC K1 wide with no slack and bring as much torque to the party as you want.
Bikers roll up (or cinch down) their right pant leg because of chain grime. Tire dust and road dirt accumulate on a greasy chain. Multi-speed bikes have longer, looser chains that move sideways every time you switch gears, and anything the chain touches will get gunked. Maybe if one were wiping and cleaning a chain on the regular it would be less of a problem, but even if your chain is pristine you’re likely getting lube on your trousers. Just because you rolled up your trousers doesn’t mean you’re in the clear. You’re going to get gunked sometime, whether it’s your socks or your skin.
I rode around the City with a rolled pant leg for almost ten years before I tried a single speed. I wish I would have done it sooner.