Citi Bike will finally begin its long-awaited expansion into the Bronx and upper Manhattan later this year, but a broader, deeper expansion into Brooklyn and long-suffering Queens will take another four years.

City — and "Citi" — officials will gather in the Bronx on Tuesday morning to herald the expansion of the Citi Bike zone, but Streetsblog obtained a truncated preview that reveals a few choice details from the Lyft-owned company, including the depth and timeline of the expansion.

Some neighborhoods won't get Citi Bike until 2023 — and some won't get it at all (sorry, Bay Ridge).