Daily Manhattan bike commuter here. You can commute on any bike that rides, but what I find helpful are: Gears, disc brakes, fenders, a rack, pannier, lights, and suitable clothing for cold or rainy weather. My bike came with gears and disc brakes; everything else I've added.
Despite my commute being mostly flat, gears are still quite useful in getting started from the frequent stops on my commute. Disc brakes work better than older alternatives and are especially better in rain. Being able to stop quickly when you need to is very important. Everything else should be explanatory.
I personally wouldn't get any use out of a bike computer or phone handlebar mount. Seems like an unnecessary complication and annoyance.
Do you have any recommendations for breathable rain gear? I basically can't use my rain gear unless its below 40 degrees, because I'll be drenched in sweat. I'd rather just change into dry clothes when I get there.
I also second the fenders, if you live somewhere that isn't California, you need fenders if you're going to ride. A seatpost mounted fender is better than nothing, but full coverage fenders with a mudflap will keep your shoes and face dry.
Despite my commute being mostly flat, gears are still quite useful in getting started from the frequent stops on my commute. Disc brakes work better than older alternatives and are especially better in rain. Being able to stop quickly when you need to is very important. Everything else should be explanatory.
I personally wouldn't get any use out of a bike computer or phone handlebar mount. Seems like an unnecessary complication and annoyance.