Abstract: A variable ratio transmission for an engine. The transmission comprises a planetary gear system having a planet ring with a plurality of planet gears rotatably connected thereto. The planetary gear system also comprises an outer drum gear and an inner sun gear. There is also a mechanism for providing a variable force against the drum gear so that the sun gear is driven by the engine with a variable ratio. The planet ring acts as an input driven by the engine and the sun gear acts as an output, such as to wheels. It should be appreciated that the input, output and providing mechanism, against the remaining gear, can be interchanged in a variety of ways to achieve the intended result of a variable transmission. Preferably, the providing mechanism provides a continuous variable force against the drum gear so that the transmission can provide a continuous variable ratio output. Thus the transmission can have an infinite number of gears ratios.