47% off

Trek Powerfly FS 4 Gen 2

By Trek
$2,499.93 $4,749.99
SKU: 1042878 // Barcode: 601842358221
View details
Powerfly FS 4 is a full suspension electric mountain bike built to tackle rugged trail adventures. The plush suspension setup soaks up rough terrain, and the powerful Bosch electric drive system boosts your capacity to crush climbs and mile after mile of singletrack.
  • For e-MTB, full suspension is a game-changer: it soaks up rugged terrain so you can ride the Bosch pedal-assist system to its full potential
  • Treks 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 to remove the battery without tools, and lets you mount a water bottle cage—even on full suspension e-MTBs
  • The dropper post lets you lower your saddle on the fly so its out of the way on descents
  • The Purion controller has Walk Assist and an intelligent eMTB mode that automatically delivers the right amount of power based on your terrain
  • Powerfly FS frames feature a curved top tube that makes standing over the bike easier. Plus, Smart Wheel Sizing means youll get the fastest wheel that fits—29˝ wheels on larger frames, 27.5˝ wheels on smaller frames

Bosch Performance Line CX motor

Bosch Performance Line CX sets the standard for eMTB performance with up to 85Nm of torque and an intelligent eMTB mode with Extended Boost that automatically adjusts the amount of assist based on the terrain.

Custom eMTB Lite mode

Trek eMTBs feature a custom eMTB Lite mode in place of Tour mode. It gives you more natural-feeling power delivery and longer battery life.

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.

Compliant with leading safety regulations

The e-systems on Trek and Electra e-bikes are third-party tested to meet the latest e-bike safety regulations, including the stringent UL 2849 certification — so all you have to worry about is where your e-bike will take you next.


Frame Alpha Platinum Aluminum, Removable Integrated Battery (RIB), tapered head tube, internal routing, Motor Armor, magnesium rocker link, rack and fender mount, ABP, Boost148, 100mm travel
Fork SR Suntour XCR 34, air spring, LO R damper, hydraulic lockout, tapered steerer, 41mm offset, oversized crown for eMTB, Boost110, 15mm bolt-on thru axle, 100mm travel
Shock SR Suntour Edge R, 190mm x 45mm
Tire Bontrager XR3 Comp, wire bead, 30tpi, 27.5x2.35
Hub Front Bontrager sealed bearing, alloy axle, 6-bolt, Boost110, 15mm thru axle
Hub Rear Bontrager Approved DC-3248, sealed bearing, alloy axle, 6-bolt, Shimano 8/9/10 freehub, Boost148, 12mm thru axle
Rim Alex MD35, tubeless compatible, 32-hole, 35mm width, Presta valve
Rim Strip Bontrager TLR
Spokes 14g stainless steel, black
Skewer Rear Bontrager Switch thru axle, removable lever
Shifter Shimano Deore M4100, 10 speed
Rear Derailleur Shimano Deore M5120, long cage
Crank FSA Bosch CK-220, 36T ring, 165mm length
Cassette Shimano Deore M4100, 11-46, 10 speed
Chain KMC X10, 10 speed
Chainring FSA, 36T, steel
Brake Rotor Tektro, 6-bolt, 203mm
Pedal VP-536 nylon platform
Saddle Bontrager Arvada, steel rails, 138mm width
Seatpost TranzX JD-YSP18, 100mm travel, internal routing, 31.6mm, 361mm length
Seat Collar Bolt-on, 36.4mm
Handlebar Bontrager alloy, 31.8mm, 15mm rise, 720mm width
Stem Bontrager Comp, 31.8mm, Blendr compatible, 7 degree, 60mm length
Headset FSA IS-2
Grips Bontrager XR Trail Comp, nylon lock-on
Fender Trek Powerfly 29 custom fender
Battery Bosch PowerTube 500Wh
Motor Bosch Performance CX, magnesium motor body, 250 watt, 85 Nm, 20mph or 32km/h max assist
Charger Bosch compact 2A, 100-240V

Geometry Chart

XS (27.5" WHEEL)S (27.5" WHEEL)M (29" WHEEL)L (29" WHEEL)XL (29" WHEEL)
B B Drop 2.4
B B Height 33.2
Chainstay Length 46.8
Eff Seat Tube Angle 76.0°
Eff Top Tube 55.4
Frame Reach 40.5
Frame Size Letter XS
Frame Size Number 14.5
Frame Stack 59.9
Head Angle 66.5°
Head Tube Length 14
Offset 4.4
Seat Tube 36.8
Seat Tube Angle 68.3°
Standover 69.1
Trail 10.7
Wheelbase 117
Wheel Size 27.5"
B B Drop 2.4
B B Height 33.2
Chainstay Length 46.8
Eff Seat Tube Angle 76.0°
Eff Top Tube 56.4
Frame Reach 41.5
Frame Size Letter S
Frame Size Number 15.5
Frame Stack 59.9
Head Angle 66.5°
Head Tube Length 14
Offset 4.4
Seat Tube 39.5
Seat Tube Angle 68.3°
Standover 69.1
Trail 10.7
Wheelbase 118
Wheel Size 27.5"
B B Drop 3.9
B B Height 33.5
Chainstay Length 47
Eff Seat Tube Angle 76.0°
Eff Top Tube 58.9
Frame Reach 43
Frame Size Letter M
Frame Size Number 17.5
Frame Stack 63.7
Head Angle 66.5°
Head Tube Length 13
Offset 4.4
Seat Tube 42
Seat Tube Angle 67.5°
Standover 71.2
Trail 11.4
Wheelbase 120.6
Wheel Size 29"
B B Drop 3.9
B B Height 33.5
Chainstay Length 47
Eff Seat Tube Angle 76.0°
Eff Top Tube 62.1
Frame Reach 46
Frame Size Letter L
Frame Size Number 19.5
Frame Stack 64.6
Head Angle 66.5°
Head Tube Length 14
Offset 4.4
Seat Tube 45
Seat Tube Angle 67.5°
Standover 71.6
Trail 11.4
Wheelbase 124
Wheel Size 29"
B B Drop 3.9
B B Height 33.5
Chainstay Length 47
Eff Seat Tube Angle 76.0°
Eff Top Tube 64.6
Frame Reach 48.5
Frame Size Letter XL
Frame Size Number 21.5
Frame Stack 64.6
Head Angle 66.5°
Head Tube Length 14
Offset 4.4
Seat Tube 50
Seat Tube Angle 67.5°
Standover 71.3
Trail 11.4
Wheelbase 126.5
Wheel Size 29"