Strip an old steel road bike to the frame. Work with a shop to equip it with a single-speed drivetrain using the rear wheel listed below, then top it all off with the following components.
1. Wheels: Paul Dorn, co-author of The Bike to Work Guide, recommends a beefy rear wheel to support the extra load (laptop, books, lunch). Have the shop lace up a Miche Primato hub (from $111; miche.it) to a Sun ME14A rim ($31; sun-ringle.com). Retread the bike's existing front wheel.
2. Pedals: Opt for sturdy two-sided BMX pedals like the Diamondback Sounds ($40; diamondbackbmx.com). If you wear cleats, the Shimano PD-M324 ($85, shimano.com) has a clipless attachment on the flip side.
3. Handlebars: Get a riser bar so you'll be more upright and visible in traffic (from $13; xlc-parts.com).
4. Lights: The main idea is to be seen. Knog offers some of the best, easiest-to-mount LED lights (from $16; knog.com.au).