>>1785559>flatGet a fixie, less shit to go wrong when your income depends on your bike, less repair costs, it'll teach you to ride well, its light, practically disposable and its fun
Meaningful upgrades:
>good tyres.23-28mm. Something that'll hold up to city debris, last a while, corner well and grip in wet, without being some meme heavy rock solid shit. These will also make your nimble thin tyres feel as comfy as a much thicker tyre and make you roll faster. Gatorskins, GP 4seasons, GP4000, buy once and cry once.
>carbon seatpost.Chink specials are fine, these will deflect a lot more than alloy and absorb road buzz, letting you do longer delivery days with less fatigue. Paint it silver so it won't get stolen.
>big flat pedalsMore efficient with more contact area, more foot positions for all day riding with less fatigue, better grip on foot
>fendersOkay, maybe less necessary if you go for a fixie, but something like SKS Chromoplastics/Raceblades or Crud Mk3s will mean much less time fucking around cleaning your drivetrain, less wet clothes sapping your heat when waiting for orders and less wet shoes needing rotating and drying daily.
>LightsDon't be a fag and skip lights, dress in bright colours too. If you're starting out you want to be seen not look cool.