The present invention is a derailleur for moving a chain to a different sized sprocket in a drive sprocket nest comprising: a feed arm for directing onto one of multiple sprockets within the drive sprocket nest when the feed arm is rotatably mounted at a pivot end onto a frame of a vehicle; a take up roller attached to the feed arm supporting the chain so that when the take-up roller moves laterally the chain moves from one sprocket to another sprocket in the drive sprocket nets; a roller feel sprocket supporting the chain so that the chain contacts over ½ the perimeter of the sprocket contacting the chain in the drive sprocket nest; an opposite chain guide end attached to the feed arm so that the chain guide end traces a path substantially parallel to a tangent to the outer periphery of the drive sprocket nests.