The 2019 Trek Powerfly 4 is an e-MTB that is built with parts that hold up, like a dependable 9-speed Shimano drivetrain, a 100 mm suspension fork, fast-rolling wheels & a Bosch Performance CX motor that assists up to 15.5 mph. Powerfly 4 is our most affordable electric mountain bike. This e-MTB is built with parts that hold up, like a dependable 9-speed Shimano drivetrain, a 100 mm suspension fork, fast-rolling wheels & a Bosch Performance CX motor that assists up to 15.5 mph. This bike expands your boundaries & lets you travel to destinations that you never thought youd reach on a mountain bike. A durable Alpha Aluminium frame with a Bosch Performance CX 250-watt motor that assists up to 25 km/h, an ergonomic Bosch Purion controller, & a long-range semi-integrated 500 Wh battery thats secure while youre riding but easy to remove for charging. Plus, a smart e-MTB mode that manages the assist level automatically, a Shimano drivetrain, an SR Suntour XCM fork & hydraulic disc brakes. Our most affordable electric mountain bike is equipped with rugged parts & a high-end Bosch motor, battery & controller for confidence & a fun boost on the trails & roads. This Bike Is Perfect For Youre sold on the e-bike revolution & want the capability & versatility of a mountain bike at a price that doesnt resemble the car youre trying to use less. You want bigger, better trail adventures & know that an e-MTB is the best way to get them. Key Features This bike expands boundaries: the top-notch Bosch system is equally suited to commuting, recreation & a ridiculously fun time on the trails The proven Bosch electric-assist system is natural & intuitive & makes you feel like you have super-charged legs This bike is built for the long-haul: it comes with a 500 Wh battery, the longest-range available from Bosch