The Powerfly electric bikes from Trek feature a dependable Bosch drive system that adds an extra kick of power when you need it most. From singletrack rides to your favorite off-road terrain, the 4 and FS 4 e-bikes will keep you riding strong.
It’s one of the best budget mountain bikes with an electric motor that Trek offers, but that doesn’t mean the Powerfly 4 is any less capable on the trails. This bike is just as sensible for new riders as it is for more experienced cyclists. Compared to its pricier siblings, the Powerfly 4 has a slightly smaller battery and more basic, yet still very dependable, components.
A well-rounded selection of parts delivers the performance you crave without driving up the bike’s price tag. This is most evident with the bike’s sleek Bosch Performance CX motor, which boasts a durable magnesium motor body and 250 watts of power. While 250 watts might seem quite tame compared to some of the beefier 750 and 1,000-watt motors on our list, this Bosch motor delivers up to 85 Nm torque for increased power, especially at lower cadences, and tops out at 20 miles per hour. In other words, you’ll still take most of the credit for a hard day of work in the saddle while having that extra boost of power as a backup when you need it most.
A dependable Bosch Purion controller keeps you focused on the essentials with minimal disruption. In addition to Walk Assist, the controller offers a smart eMTB mode that provides the necessary power for your terrain.
Another noteworthy feature is the bike’s Removable Integrated Battery (RIB). A built-in handle makes it easy to remove and charge the battery. The battery is hidden inside the frame for maximum protection and can be removed without tools. Plus, this design makes it easier to install a water bottle cage.
A 10-speed Shimano Deore M4100 cassette (11-46) provides a greater gear ratio for your favorite trails, so you don’t have to worry about losing speed as you rapidly transition from a fast and flat track to a steep climb.
Other drivetrain components include a dependable 10-speed KMC X10 chain, FSA Bosch CK-220 (36T ring) crank with 165mm length, a 10-speed Shimano Deore M4100 shifter and a Shimano Deore M5120 rear derailleur.
No matter how rough or technical the terrain gets, the bike’s SR Suntour XCM 34 front fork with preload and lockout keeps you comfortable. The fork on the extra-small frame has 80mm travel, while the small through extra-large bikes boast 120mm travel. There’s also a slight difference in tires between the extra-small and small bikes, which run Bontrager XR3 Comp 27.5 x 2.35-inch tires, and the larger 29 x 2.30-inch tires on the medium through extra-large models.
Technical details aside, the Powerfly is a comfortable and confident bike that’s built for extended use on your favorite trails. Seemingly small details matter more when you head out for a day of exploring, such as Trek’s innovative built-in wiring that allows you to power your bike’s lights using the motor. There’s also plenty of room to install a rear bike rack and fenders.
Upgrade to the Powerfly FS 4 if you’re looking for a full-suspension electric mountain bike.