I am a bike mechanic. This product does not make your bike a fixed gear or a "fixie". It will make a bike that has a freeHUB rear wheel with multiple speeds into a single speed which will still "freewheel" or "coast" like a traditional bicycle. Also, installing this requires a cassette removal tool and a chain whip, two tools that most people are not likely to own. Lastly, this will not work on a bicycle which has a thread on multiple gear freewheel on the rear wheel. It is only for freeHUB rear wheels. An item like this should really be installed by a professional bike mechanic.