Descending
55
A solid all-round descender (66.5° head angle, 100mm) — capable in the rough and steep without being an all-out bruiser.
Trek
Powerfly FS 2024
Discontinued✎Full Power · Cross-CountryLegacy · 1.6/10iFreshness 1.6/10
How current the bike is — newer chassis, motor and battery score higher. 10 = brand-new, 0 = legacy.
How current the bike is — newer chassis, motor and battery score higher. 10 = brand-new, 0 = legacy.
Dependable alloy trail bike with modest travel and reliable Bosch power
Motor
Bosch Performance Line CX Gen 4 · 85Nm · 600W↗
Battery
Bosch PowerTube 500 · 500Wh
Travel F/R
120/100mm
Wheels
29F / 29R✎
Frame
Aluminium✎
Weight
24.64 kg
Price
From £0
From £4,400
EMTB Forums verdict
The Trek Powerfly FS was Trek's full-suspension full-power trail eMTB, sitting one step up from the hardtail Powerfly. The Alpha Platinum aluminium frame runs 120mm up front and 100mm of rear travel through Trek's ABP rocker-link suspension, a comparatively short-travel setup aimed at cross-country and flowing trail riding rather than aggressive enduro work. Trek's Smart Wheel Sizing fits 29in wheels on M/L/XL and 27.5in on XS/S, with a 66.5 degree head angle and 76 degree effective seat angle across the range.
Power came from the Bosch Performance Line CX (Gen 4) motor rated at 85 Nm. The FS 4 Gen 3 and FS 9 Equipped Gen 3 ran Bosch's Smart System electronics, while the carryover FS 4 Gen 2 used the earlier Bosch CX with a Purion display. Batteries were the Bosch PowerTube 500Wh on the FS 4 builds and the larger 625Wh on the FS 9 Equipped. All packs use Trek's tool-free Removable Integrated Battery (RIB) system.
The 2024 lineup spanned the value-focused FS 4 (Shimano Deore 10-speed, SR Suntour fork and shock, Tektro brakes) up to the FS 9 Equipped, which added a wireless SRAM GX Eagle AXS drivetrain, RockShox SID Lux shock, SRAM G2 RS 4-piston brakes plus a rack, lights, kickstand and fenders for commuting duty on the same trail frame.
The Powerfly FS has since been discontinued and replaced by the current Bosch Smart System Gen 5 Powerfly FS+ generation. There is no forum owner data attached to this entry.
Geometry read
What the numbers mean on the trail
Computed from this bike's geometry, spec and build kit — reach, wheelbase, chainstay, head and seat angles, travel, motor, weight and the fork/tyre/brake spec — and worked out per size, because a fixed chainstay can make an S and an XL feel very different.
Size
Wheels
Playfulness
53
A fair bit of pop, but happiest on flowing trail rather than trials moves.
Size balance
68
Rear-long with a planted front in L (FC:RC 1.64) — easy to weight the front and quick to turn, though it can feel light at the back at real speed.
Technical climbing
77
Bosch Performance Line CX Gen 4 and a steep 76° seat angle keep the weight planted over the front — a proper winch. 600W of peak power and 85Nm of torque — a strong full-power motor.
No single standout trait — a balanced, versatile bike.
The numbers are well balanced for its category.
How it stacks up vs other Full Power · Cross-Country bikes (from 130 bikes in the database)
Weight24.64 kg1.0 kg heavier than average
Battery500 Wh186 Wh below average
Motor torque85 Nmabout average torque
Value for money11/100from £4,400 · most Bosch Performance Line CX Gen 4 bikes ~£3,499
Computed from geometry + spec, not a paid review. Scores are guidance, not gospel.
💬 Forum discussion
Trek Powerfly FS 2019 - scrapping/tinny noise
8 replies · 5.5k views · last reply 86 months ago
Join the discussion →
“I used to get a tinny rattle from my rear disc @ ~15mph on my LT7. Changed to some different discs and the noise has gone.”
— thewildblue · ♥ 3 · most-liked post
Geometry · hover a row to highlight the measurement on the bike
| XS | S | M | L | XL | |
|---|---|---|---|---|---|
| Reach | 405 mm | 415 mm | 430 mm | 460 mm | 485 mm |
| Stack | 599 mm | 599 mm | 637 mm | 646 mm | 646 mm |
| Seattube | 368 mm | 395 mm | 420 mm | 450 mm | 500 mm |
| Chainstay | 468 mm | 468 mm | 470 mm | 470 mm | 470 mm |
| Headtube Angle | 66.5° | 66.5° | 66.5° | 66.5° | 66.5° |
| Seattube Angle (eff) | 76° | 76° | 76° | 76° | 76° |
| Wheelbase | 1170 mm | 1180 mm | 1206 mm | 1240 mm | 1265 mm |
| Headtube | 140 mm | 140 mm | 130 mm | 140 mm | 140 mm |
| BB Height | 332 mm | 332 mm | 335 mm | 335 mm | 335 mm |
| Standover | 691 mm | 691 mm | 712 mm | 716 mm | 713 mm |
| Front Centre | 702 mm* | 712 mm* | 736 mm* | 770 mm* | 795 mm* |
| FC:RC | 1.50 | 1.52 | 1.57 | 1.64 | 1.69 |
Trims · 3
FS 4 Gen 3 £4,400 | FS 9 Equipped Gen 3 £5,550 | FS 4 Gen 2 £0 | |
|---|---|---|---|
| Motor | Bosch Performance Line CX Gen 4 · 85 Nm · all trims | ||
| Battery | Bosch PowerTube 500 · 500 Wh · all trims | ||
| Travel F/R | 120/100 mm · all trims | ||
| Frame | Alpha Platinum Aluminium · all trims | ||
| Fork | SR Suntour XCR 34, air spring, LO R damper, hydraulic lockout, tapered steerer, 120mm travel (XS & S: 520mm axle-to-crown, M & up: 545mm axle-to-crown) | SR Suntour Zeron 35, air spring, LO R damper, hydraulic lockout, tapered steerer, 44mm offset, 120mm travel (XS & S: 520mm axle-to-crown, M & up: 545mm axle-to-crown) | SR Suntour XCR 34, air spring, LO R damper, hydraulic lockout, tapered steerer, 120mm travel (XS & S: 520mm axle-to-crown, M & up: 545mm axle-to-crown) |
| Shock | SR Suntour Edge R, 190mm x 45mm | RockShox SID Lux Select+, 190 x 45mm | SR Suntour Edge R, 190mm x 45mm |
| Headset | FSA IS-2 · all trims | ||
| Stem | Bontrager Comp, 31.8mm, Blendr compatible, 7 degree (XS/S 60mm) | Bontrager Elite, 31.8mm, Blendr light mount, 7 degree rise (XS/S 60mm) | Bontrager Comp, 31.8mm, Blendr compatible, 7 degree (XS/S 60mm) |
| Handlebar | Bontrager alloy, 31.8mm, 15mm rise, 720mm width | Bontrager Rhythm Comp, alloy, 31.8mm, 15mm rise, 750mm width | Bontrager alloy, 31.8mm, 15mm rise, 720mm width |
| Grips | Bontrager XR Trail Comp, nylon lock-on | Bontrager XR Endurance Comp, lock-on | Bontrager XR Trail Comp, nylon lock-on |
| Saddle | Bontrager Arvada, steel rails, 138mm width | Bontrager Commuter Comp | Bontrager Arvada, steel rails, 138mm width |
| Seatpost | TranzX JD-YSP18 dropper (XS/S/M 100mm, L/XL 130mm), internal routing, 31.6mm | Bontrager Line Dropper (XS/S/M 100mm), internal routing, 31.6mm | TranzX JD-YSP18 dropper (XS/S/M 100mm, L/XL 130mm), internal routing, 31.6mm |
| Brakes | Tektro HD-M275 hydraulic disc | SRAM G2 RS 4-piston hydraulic disc, SRAM 200mm rotors (frame max 203mm) | Tektro HD-M275 hydraulic disc |
| Rear derailleur | Shimano Deore M5120, long cage | SRAM GX Eagle AXS | Shimano Deore M5120, long cage |
| Crank | FSA Bosch CK-220, 36T ring, 165mm length | SRAM X1 1000, 165mm length | FSA Bosch CK-220, 36T ring, 165mm length |
| Shifters | Shimano Deore M4100, 10 speed | SRAM GX Eagle AXS, 12 speed | Shimano Deore M4100, 10 speed |
| Cassette | Shimano Deore M4100, 11-46, 10 speed | SRAM Eagle XG-1275, 10-52, 12 speed | Shimano Deore M4100, 11-46, 10 speed |
| Chain | KMC X10, 10 speed | SRAM GX Eagle, 12 speed | KMC X10, 10 speed |
| Drivetrain | Shimano Deore M5120, long cage; FSA Bosch CK-220, 36T ring, 165mm length; Shimano Deore M4100, 10 speed; Shimano Deore M4100, 11-46, 10 speed; KMC X10, 10 speed | SRAM GX Eagle AXS; SRAM X1 1000, 165mm length; SRAM GX Eagle AXS, 12 speed; SRAM Eagle XG-1275, 10-52, 12 speed; SRAM GX Eagle, 12 speed | Shimano Deore M5120, long cage; FSA Bosch CK-220, 36T ring, 165mm length; Shimano Deore M4100, 10 speed; Shimano Deore M4100, 11-46, 10 speed; KMC X10, 10 speed |
| Wheels | Alex MD35, tubeless compatible, 32-hole, 35mm width | Bontrager Line Comp 30, Tubeless Ready (XS/S 27.5in, M/L/XL 29in) | Alex MD35, tubeless compatible, 32-hole, 35mm width |
| Tyres | Bontrager XR3 Comp, 30tpi (M/L/XL 29x2.30in, XS/S 27.5x2.35in) | Bontrager LT4 Expert, reflective strip, 60 tpi (M/L/XL 29x2.40in, XS/S 27.5x2.40in) | Bontrager XR3 Comp, 30tpi (M/L/XL 29x2.30in, XS/S 27.5x2.35in) |
| Weight | 24.64 kg | 26.98 kg | 24.83 kg |
| Price | £4,400 | £5,550 | £0 |
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