MAHLE SmartBike Systems X20 Ebike Hub Motor - Class 1 20mph 55nm 28h Straight-Pull 12x142mm Thru-Axle Cassette Body Not IncludedMAHLE Smartbike Systems X20 Ebike Hub Motor Class 1 20mph 55Mm 28h Straight Pull 12x142mm Thru Axle Black. The MAHLE X20 Hub motor provides assistance in a compact unobtrusive package. The 36V 250W motor offers up to 55nm of torque to assist up to 20mph. This cutting edge system is designed for high performance Gravel Road and Cross Country bikes. The entire package when paired with the wiring and battery weighs in at just 3. 2kg and is drag free when