?? Is this Motor Kits Compatible With My BiKE? The length of the bottom bracket (BBS) is. Matching the bicycle the length of the bottom bracket is 68-73MM. Matching the bicycle the length of the bottom bracket is 83-100MM. If the length of the bicycle bottom bracket is 83MM, you need to add 210MM washers. If the length of the bicycle bottom bracket is 90MM, you need to add 110MM washer. Matching the bicycle the length of the bottom bracket is 110-120MM. If the length of the bicycle bottom bracket is 110MM, you need to add 110MM washer. 36V 250W 350W 500W/48V 750W:The length of the bottom bracket is 68-73mm 48V 1000W:The length of the bottom bracket is 68mm, 100mm, 120mm. Please forecast whether the sprocket willapproach the chain stay after installing themotor and sprocket. 68m m-73mm Standard JlS4. Inner diameter of the bracket should be no4less than 33.5mm. The parcel will include extra gaskets for 73mm bottom bracket. NOT recommendedto install this motor to bikes with carbonfiber frame in case of damaging the frame.