Fixed-gear bikes, also known as "fixies," are generally legal in most countries. However, local laws and regulations may require bicycles to have certain safety features, such as brakes, reflectors, or lights. For fixed-gear bikes, some jurisdictions require at least one functioning brake, typically a front brake, to be considered road-legal. It's essential to check the specific laws and regulations in your area to ensure your fixed-gear bike complies with local requirements. Keep in mind that riding without brakes or necessary safety features can be dangerous, and it's always a good idea to prioritize safety when cycling in any environment.