singlespeed

Singlespeed refers to a bicycle configuration that uses a single gear ratio, with one front chainring and a single rear cog, and no derailleur or multiple sprockets. The rider remains at a constant gear, selecting cadence to match terrain. This setup is used on purpose-built singlespeed bikes and on some conversion bikes that remove gears from a standard bicycle.

Two main varieties exist: fixed-gear and freewheel. In a fixed-gear (fixie) system the rear cog is directly attached to the wheel, so pedaling drives the wheel and coasting is not possible. In a single-speed with a freewheel, the rear hub allows the wheel to turn without pedaling. Some bikes use flip‑flop hubs that can be swapped between fixed and freewheel configurations.

Most singlespeed bikes simplify maintenance, with fewer moving parts and no derailleurs or gear shifters. Frame end options affect chain tension: horizontal dropouts or track ends allow easy tensioning; vertical dropouts often require chain tensioners. Proper chainline and tension are important for performance and longevity, as a loose chain can skip or derail, and an overly tight chain increases wear.

Advantages include simplicity, lighter weight, lower cost, and easy maintenance, making them popular for urban commuting and track riding. Disadvantages are limited gearing, reduced performance on hills, and less versatility across varied terrain. Braking requirements vary by jurisdiction and setup, with many riders using at least one brake on fixed or freewheel configurations.

Singlespeed design has roots in track cycling and urban cycling cultures, and remains a niche but enduring option for riders seeking simplicity.