Powerfly FS+ 8 Gen 4
Trek
Trail
Powerfly FS+ 8 Gen 4 is an alloy electric trail mountain bike (2025), by Trek, from the Powerfly lineup. Rider-wise, it fits a wide range of riders thanks to its fit flexibility, with a setup that gives you a balanced riding position, and is well suited to natural trails and mixed off-road terrain. The main strengths in the metrics are strong climbing friendliness for sustained uphill riding, a balanced ride feel between comfort and directness, and good fit flexibility for dialing in rider position. What it gives up slightly is a value score that depends more on priorities than pure price efficiency. Compare this bike across categories on MatchBikes.com to see whether a nearby segment gives you a better fit.
Rating

Score Summary
Performance
Built for speed and efficiency
Fit
Dialed-in Fit & Comfort
Value
Battery
Specifications
General
Frame
Drivetrain
Wheels
Brakes
Cockpit
Seat
E-Bike Components
Geometry
| Measurement | 15.5" | 17.5" | 19.5" | 21.5" |
|---|---|---|---|---|
| Stack Reach Ratio | 1.405 mm | 1.398 mm | 1.362 mm | 1.332 mm |
| Bottom Bracket Height | 330 mm | 335 mm | 335 mm | 335 mm |
| Front Center | 745 mm | 766 mm | 799 mm | 832 mm |
| Rake | 49 mm | 50 mm | 50 mm | 50 mm |
| Trail | 123 mm | 125 mm | 125 mm | 125 mm |
| Stack | 597 mm | 629 mm | 647 mm | 666 mm |
| Reach | 425 mm | 450 mm | 475 mm | 500 mm |
| Top Tube Length | 563 mm | 595 mm | 630 mm | 654 mm |
| Seat Tube Angle | 77 ° | 77 ° | 77 ° | 77 ° |
| Seat Tube Length | 380 mm | 400 mm | 420 mm | 450 mm |
| Head Tube Angle | 65 ° | 66 ° | 66 ° | 66 ° |
| Head Tube Length | 130 mm | 110 mm | 130 mm | 150 mm |
| Chainstay Length | 458 mm | 461 mm | 461 mm | 461 mm |
| Wheelbase | 1201 mm | 1223 mm | 1257 mm | 1290 mm |
| Bottom Bracket Drop | 30 mm | 45 mm | 45 mm | 45 mm |
| Standover Height | 756 mm | 780 mm | 775 mm | 778 mm |
| Wheels | 27" | 29" | 29" | 29" |
| Rider Min Height | 155 cm | 164 cm | 175 cm | 187 cm |
| Rider Max Height | 166 cm | 178 cm | 189 cm | 195 cm |




























































