The Trek Powerfly+ FS 4 Gen 4 is what Trek calls a full-power, full-suspension e-MTB. For $4,499.99 you get Bosch’s Performance Line CX motor, a 600Wh battery, 130mm of travel up front and 120mm in back. That’s less travel and less battery than Trek’s Rail+, but the Powerfly+ is $500 cheaper. I haven’t ridden it. The closest bike I’ve filmed is the Aventon Ramblas, a mid drive hardtail, and I’ll compare them below with the full-suspension bikes already on this site. Everything here comes from Trek’s product pages, checked on Oct 28, 2026 and linked at the bottom.
What it’s built for
Trek pitches the Powerfly+ FS as a bike for alpine adventures and rough trails. With 120mm of rear travel, it sits between the Marlin+ hardtails and the longer-travel Rail+. It’s Class 1: pedal assist up to 20 mph, with no throttle. Trail rules for e-bikes vary, so check before you ride. Our e-bike classes guide explains the classes.
On Oct 28, 2026, every size and color was out of stock on Trek’s site, so you may need to order through a store or wait.
Motor and battery
Trek’s torque numbers don’t fully agree. The spec summary gives a range of 85 to 120 Nm. A feature blurb says the motor ships at 85 Nm and can be tuned up to 100 Nm and 750W in the Bosch eBike Flow app. Expect 85 Nm out of the box, and ask a Trek store what your bike can be tuned to.
The 600Wh Bosch PowerTube sits inside the down tube. Trek’s RIB 2.0 design lets you remove it for charging, with a second catch so it can’t drop out. Trek doesn’t list a range. A 250Wh PowerMore extender is available, and Bosch’s 2A charger is included. The controls are the Purion 200, and the eBike Flow app adds custom assist settings, ride tracking and navigation.
Suspension and frame
The fork is a RockShox Recon Silver with 130mm of travel, an air spring and a lockout. The rear shock is a RockShox Deluxe Select R. The aluminum frame has Trek’s Active Braking Pivot, which Trek says lets the suspension respond to braking and pedaling separately. It also has a Mino Link to adjust the geometry and mounts for a rack and mudguards. Trek offers a suspension calculator to help set the sag for your weight.
Parts
- Brakes. Tektro Gemini SL 4-piston hydraulic brakes with 203mm rotors. Trek’s description names a different Tektro 4-piston model, the HD-M5140.
- Gears. Shimano CUES 10 speed with an 11 to 48 cassette, which Trek picked for durability.
- Wheels and tires. Bontrager Gunnison Pro XR tires at 2.4 in, set up tubeless with sealant included. Size S rolls on 27.5 in wheels, and M to XL on 29 in.
- Dropper. A Bontrager Line Dropper with 100mm of travel on the S and 170mm on M to XL.
Trek lists 56.4 lb for a size M, set up tubeless. The total limit is 300 lb, including the bike, which leaves about 244 lb for the rider and gear.
How it compares
Against the Trek Rail+ 5 Gen 5: it uses the same CX motor family, with an 800Wh battery, a 160mm fork and 160mm of rear travel, and weighs 54.64 lb in size M. It was $4,999.99 on Oct 28, 2026. For $500 more, the Rail+ has more battery and much more travel at about 2 lb less. The Powerfly+ is the shorter-travel bike for less money.
Against the Cannondale Moterra Neo 4: it’s also a Performance Line CX bike with a 600Wh battery, listed at $4,499 on Oct 26, 2026, when it was out of stock online. The two match closely on paper, so the choice may come down to which one your local shop can get.
Against the Aventon Ramblas, which I filmed: the Ramblas is a hardtail with a coil fork and no rear suspension. Aventon now sells it as the Ramblas ADV and lists 100 Nm, a 708Wh battery and about 54 lb. On paper, the Ramblas has more battery and torque. The Powerfly+ adds rear suspension and Bosch’s system.
Trek’s Rail+ 8 Gen 5 uses the same 800Wh, 160mm platform as the Rail+ 5 with a RockShox Lyrik fork, a Super Deluxe shock and SRAM Eagle 70, at $5,999.99 and 54.42 lb. If you’d rather ride a hardtail, the Marlin+ 8 is Trek’s top Bosch hardtail.
FAQ
Have I ridden the Powerfly+ FS 4 Gen 4?
No. This page is based on Trek’s product pages, checked Oct 28, 2026.
How much torque does it have?
Trek’s spec summary says 85 to 120 Nm. A feature blurb says 85 Nm out of the box, tunable to 100 Nm in the eBike Flow app. Ask a Trek store for the setting that applies to your bike.
How much travel does it have?
130mm up front and 120mm in back.
Does it have a throttle?
No. It’s a Class 1 pedal assist bike that helps up to 20 mph.
Is it in stock?
Not online. Every size and color was out of stock on trekbikes.com on Oct 28, 2026.
Pros and cons (from the specs and sources)
Pros: Bosch Performance Line CX on a full-suspension Trek for $4,499.99; 130mm fork and 120mm rear travel; removable 600Wh battery with a safety catch; 4-piston brakes with 203mm rotors; dropper post; tubeless setup; rack and mudguard mounts; $500 less than the Rail+ 5.
Cons: out of stock online on Oct 28, 2026; 600Wh and no range figure; 56.4 lb; 300 lb total limit; no throttle; Trek’s torque and brake listings conflict.
Who it’s for
On paper, the Powerfly+ FS 4 fits trail riders who want full suspension and a strong Bosch motor without paying for a longer-travel bike, and who are happy with 120mm of rear travel instead of the Rail+‘s 160mm. If you want more travel and battery, the Rail+ 5 is $500 more.
Price
$4,499.99 on trekbikes.com as of Oct 28, 2026, out of stock online that day.
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