Notes on installation: It is important to use blue (do not use red) Locktight on the large round fixing nut. I also use it on the final locking nut. Sometimes the amount of threads left after tightening the large retaining nut are to few, if that is the case leave the locking nut off. Make sure the motor is even and firm against the down tube. There will be times when you may have to remove anything that is blocking the motor from fitting level on the down tube. If you have shift or brake cables running down the down tube and under the bottom bracket shell, make sure the motor is not inhibiting their smooth movement. When needed, I will cut down the cable guide to accommodate the motor. Also, I place a piece of hard rubber between the motor and the down tube to allow a little space for the cables to move smoothly. By the way, 8Fun and Bafang are the same company. Motors that are sold in Europe are called 8Fun. Why? Who knows.