Box Three Prime 9 ebike replacement sprockets
The Box Three Prime 9 ebike rated drivetrain is both durable and affordable. However, with high power motors, you will still wear out the higher (smaller) gears on the rear cassette. Fortunately, Electrify Bike Co. has arranged with Box to sell these as a set of 4 sprockets for just $20 so you can just change them out when they start to slip.
Includes Gears: 12 - 14 - 16 - 18 (not the full cassette as pictured)