Powerfly 4 is our most affordable electric mountain bike. It's built with parts that hold up, like a dependable 9-speed Shimano drive train, a 120 mm SR Suntour fork and a powerful Bosch Performance CX motor. Plus, it features our user-friendly Removable Integrated Battery (RIB) system that's fully encased in the frame yet doesn't require tools for removal. This bike expands your boundaries and lets you travel to destinations that you never thought you'd reach on a mountain bike.

You're sold on the e-bike revolution and want the capability and versatility of a mountain bike at a price that doesn't resemble the car you're trying to use less. You want bigger, better trail adventures and know that an e-MTB with the latest user-friendly tech is the best way to get them.

A lightweight and durable Alpha Platinum Aluminium frame that fully encases a long-range 500 Wh battery for sleek looks and protection on the trail, a Bosch Performance CX (250 W, 75 Nm) motor that assists up to 25 km/h, an ergonomic Bosch Purion controller, a Shimano drive train, a 120 mm SR Suntour XCR fork with lockout and hydraulic disc brakes. Plus, Smart Wheel Sizing means you'll get the fastest wheel that fits - 29? wheels on larger frames, 27.5? wheels on smaller frames.

Our most affordable electric mountain bike is equipped with performance parts, a high-end Bosch motor, powerful battery and intuitive controller for confidence and a fun boost on trails and roads.
- Trek's Removable Integrated Battery (RIB) system looks great and is super user-friendly: it fully hides the battery in the frame for protection, makes it easy remove the battery without tools and lets you mount a water bottle cage
- This bike expands boundaries: the top-notch Bosch system is equally suited to commuting, recreation and a ridiculously fun time on the trails
- The Purion controller has Walk Assist and an intelligent eMTB mode that automatically delivers the right amount of power based on your terrain
- It's equipped with an external charging port for easy charging on or off the bike
- It rides like a trail bike because it is one: Powerfly is built according to Trek's trail heritage with mountain bike tech developed over decades of innovation

Will my bike have a curved top tube?
Smaller frames (S) have a top tube that dips down as it approaches the seat tube. This design makes for a lower standover height, which is good for shorter riders because it allows them to straddle their bike more easily. The larger frames (M and ML) have a straight top tube because taller riders with longer legs typically don't have the same issues with standover height.

New Bosch Performance Line CX
The all-new Bosch Performance Line CX motor is lighter, smaller and quieter than previous versions, for cleaner integration and more nimble handling. It's also more efficient so you can go further on a single battery charge. Use the intelligent eMTB mode to automatically adjust the amount of assist to match the terrain. It's a set-and-forget mode that delivers just the right amount of power so you can focus on enjoying the ride.

Removable Integrated Battery
RIB is a one-piece battery and cover with a built-in handle that can easily be removed and re-installed in the frame with no tools and no hassle. It's the most convenient way to remove your battery for transport, security or just easier charging.

What is the range?
To see how far you can ride your electric mountain bike on a single charge, check out Bosch's range calculator. We've auto-filled the variables for this bike model and the average rider, but you can make adjustments to get your most accurate estimate.