sidecars

A sidecar is a one-wheeled passenger compartment attached to the side of a motorcycle, scooter, or bicycle. It has its own wheel, frame, and suspension, and can be detachable or permanently affixed. A sidecar increases seating capacity and provides cargo space, but it also affects handling and weight distribution. Sidecars are a common feature of vintage motorcycles and remain in contemporary use in certain regions and for particular bikes.

Historically, sidecars emerged in the early 20th century for passenger transport and light cargo and later declined in general use as cars became more widespread. Variants include fixed and detachable units, with some designs offering steerable or semi-flexible connections. The added mass on one side changes steering and stability, requiring riders to adjust their technique, especially during turns and braking. Proper mounting, balance, and alignment are important for safe operation.

In software engineering, the sidecar pattern involves running a separate process or container alongside the main application within the same deployment unit. The sidecar provides ancillary services such as logging, monitoring, authentication, proxying, or data transformation. It communicates with the primary process over localhost or shared resources. Benefits include modularity, reusability, and isolation of concerns; drawbacks include resource contention, complexity, and coordination overhead.

Sidecar also refers to a classic beverage, the Sidecar cocktail, traditionally made with cognac, orange liqueur, and lemon juice, shaken or stirred and served in a sugar-rimmed glass.