JetBlack S1 Sport Turbo
This intro trainer is about as simple as it gets, but it's good enough if it's all you can afford. The simple rectangular-section steel frame, metal roller, magnetic resistance engine and small flywheel come assembled, which is a get-on-and-go bonus. The small flywheel means it picks up speed fast, with no wheel slip. And there's enough resistance to get you sweating with a compact chainset. Best for short intervals rather than long sit-and-spin sessions.