Looking at upgrading my rear shock on my Engwe engine pro. Saw on Amazon a lady do hers on same bike and she told me what size and bushings to get. JFOYH 150mm 1000lbs coil - oil adjustable . Looking to improve my ride because all my back surgeries I've had and I like riding smooth ground for you know health. So has any of you done or think about coil oil shocks? Some say air is a pain and others say cost .