Trek Powerfly FS+ 8

The Trek Powerfly FS+ 8 is the full-power e-MTB for rides that start with a big climb, wander through miles of forest tracks and still leave plenty in the tank for a favourite trail-centre loop. Its Bosch Performance Line CX smart system supplies 85 Nm of assistance, while the removable 800 Wh Bosch PowerTube battery makes long days and off-bike charging far more practical. With 120 mm of rear suspension, it is aimed at covering distance and enjoying moderate singletrack rather than impersonating a downhill bike.

Compare live UK Trek Powerfly FS+ 8 prices

There are two current electronic-shifting packages under the same Powerfly FS+ 8 name, both with an official UK RRP of £5,250. Choose by the drivetrain and brake package shown on the offer, rather than the name alone: one uses Shimano XT Di2 and Shimano XT four-piston brakes, while the other has SRAM GX Eagle AXS T-Type shifting and SRAM DB8 four-piston brakes. Gloss Lava/Matte Dark Web normally identifies the SRAM build, while Blue Sage/Catalina Fog identifies the Shimano version. Mulsanne has appeared across more than one catalogue period, so the drivetrain is the more reliable clue.

What is the latest Trek Powerfly FS+ 8 generation?

Trek calls the current platform the Powerfly+ FS 8 Gen 4. It keeps an aluminium frame, Trek's removable RIB 2.0 battery integration and practical mounting points, then combines them with full Bosch power and electronic 12-speed shifting. The result makes sense for riders who want an assisted mountain bike that can handle a long countryside outing, repeated climbs and a sensible amount of day-to-day utility with compatible luggage or mudguard kit fitted.

Gen 4 frame, sizing and likely ride character

The Gen 4 frame uses 120 mm of rear travel, an ABP suspension arrangement and a Fox Float Rhythm shock. That is enough suspension to smooth out roots, braking bumps and rough tracks while keeping the bike's character more responsive than a long-travel e-MTB. The SRAM GX AXS build has a confirmed 130 mm Fox Rhythm 36 fork. Fork travel on the current Shimano XT Di2 build needs confirming against the exact offered bike and size, particularly for size S, so a generic 150 mm claim should not be treated as settled.

Wheel format follows frame size rather than personal preference. Size S uses 27.5-inch wheels and a 100 mm dropper post, helping smaller riders get a proportionate setup. Sizes M, L and XL move to 29-inch wheels with a 170 mm dropper, bringing more rollover on longer routes. The frame is not designed to swap between wheel diameters or create a mixed-wheel arrangement.

On flowing trails and linking tracks, the Powerfly's moderate travel, Bosch assistance and upright-enough climbing position should make it an easy bike to place and keep moving. It has the capacity for blue and red trail-centre routes within your skill level, repeated climbs and all-day exploration. Steep, broken descents ask more of its 120 mm rear platform than they do of a longer-travel machine, so riders whose weekends revolve around aggressive descending will benefit from a more descent-led design.

Shimano XT Di2 vs SRAM GX AXS builds

Current Shimano XT Di2 build: This package combines Shimano XT Di2 electronic shifting with a Shimano 10-51-tooth cassette, Shimano XT four-piston brakes and 200 mm rotors front and rear. It uses Bontrager Line TLR 30 wheels with a Rapid Drive 108 rear hub. Trek claims a 24.88 kg weight for a size M with tubeless sealant and no inner tubes.

SRAM GX AXS build: The alternative uses SRAM GX Eagle AXS T-Type electronic shifting and a 10-52-tooth cassette, paired with SRAM DB8 four-piston brakes. It has Bontrager Line Comp 30 wheels and the confirmed 130 mm Fox Rhythm 36 fork. Its claimed size-M weight is 24.48 kg. Both packages retain the same 800 Wh battery, 120 mm rear travel and size-specific wheel arrangement, so the choice is chiefly about the drivetrain, braking and wheel specification you prefer.

UK maintenance, battery care and practical ownership

The 800 Wh battery can be removed for charging or storage, which is handy when the bike lives in a shed, garage or vehicle. UK motor assistance cuts out at 25 km/h, so the bike's mass becomes more noticeable on faster tarmac links or whenever you are pedalling without assistance. At roughly 25 kg complete, it is also a substantial lift for stairs and vehicle racks. If you transport it by car, use a carrier whose individual-bike rating comfortably exceeds 24.88 kg and follow any battery-removal instructions for that rack.

PowerMore range extension is compatible for unusually long days, but it is an aftermarket addition requiring the PowerMore battery, a 100 mm reversed cable and mounting hardware. Compatible racks and full mudguards are also optional rather than supplied equipment. A compatible 600 Wh battery can create a lighter setup for shorter rides, provided the correct RIB 2.0 hardware is used where needed.

Like any full-suspension e-MTB, this is happiest with regular attention rather than a winter of neglect. Wet, gritty riding calls for frequent drivetrain cleaning plus periodic checks of brake pads, suspension pivots and the battery interface. Factor in Bosch-system support and fork and shock servicing as part of ownership, particularly if the bike will see plenty of muddy miles.