There are all kinds of bikes you could ride in the city – and some which you shouldn't — but as far as a serious commuting rig is concerned, I think it boils down to the two types you can see above: vintage steel road bikes and hybrid bikes.
Their main distinguishing difference is riding stance; a road bike you ride stretched out, while a hybrid you ride with a more upright posture. Choosing the one that is right for you means finding your preferred trade-off between speed and comfort.
The case for stretching out
Road bikes are designed to go fast. Since most of your pedal power goes into parting the incoming air stream when you're at speed, curved road handlebars are so designed in order to lower the frontal area you present to the wind, which lowers the air drag. In terms of cost and availability, an older lugged road bike made of quality steel tubing from Europe or Japan can be sourced through your local online classifieds at a reasonable cost. In particular, the mid-tier road bikes of the "sports-touring" variety – churned out in the millions during the "Bike Boom" of the 70s – generally feature frame eyelets and braze-ons that make attaching fenders or carriers a snap.
On the flip-side, a road bike can take some getting used to. Road saddles are narrower and longer, exerting more pressure on your pubic bone. Another annoyance is the fact that brake levers are harder to reach if you're not riding in the lower part of the bars, called the drops. Vintage road bike purists may sneer, but swapping out the curved road handlebars for flat bars is a perfectly acceptable upgrade for an urban road bike.
The case for riding upright
Hybrid bikes are the late-80s bastard child of mountain bikes (which are themselves distant relatives of the balloon-tire cruiser bikes your parents rode in their youth). They have a wider range of gears than road bikes, and their beefier saddles are built with more support for your buttocks, since your upright stance leads to a different weight distribution.
Another advantage of hybrids is that some are made from lighter materials, such as aluminium. Your back will certainly thank you if you need to lug your ride up and down stairs on the reg. Nonetheless, aluminium bikes can be a harsher ride, because the frame material is stiffer than steel. And while aluminium doesn't soak up bumps in the road the same way that steel does, the wider tires hybrid bikes are generally fitted with do mitigate some of this.
There is no right answer to which type of bike is best for you for daily commuting use. If you're considering joining our ranks, do try out these two different styles, and choose the one (or more than one) that feels right for you. And remember — the optimal number of bikes you should own is always n+1 (where n is the number of bikes you own now).
[Image by author]