Trek Powerfly FS 4

Long climbs, lumpy bridleways and rough forest tracks are much more inviting when the bike takes some of the sting out of them. The Trek Powerfly FS 4 is Trek's value-led full-suspension, full-power e-MTB for riders who want that extra comfort and traction without stepping into a premium long-travel build. It makes particular sense if you are moving on from an e-MTB hardtail, returning to riding, or planning bigger mixed-surface days where a removable battery and a calmer ride matter more than a low headline weight.

What is the latest Trek Powerfly FS 4?

The familiar Powerfly FS 4 name remains useful, but Trek officially calls the current bike the Powerfly+ FS 4 Gen 4. It is a full-suspension platform with 130 mm of fork travel and 120 mm at the rear, plus the Bosch Performance Line CX smart system. The current frame uses Trek's RIB 2.0 removable battery arrangement, so you can take the main battery indoors for charging, storage or transport rather than having to park beside a socket.

This is an adventure-minded e-MTB rather than a gravity race bike. The suspension, dropper post and trail tyres should make roots, ruts and broken tracks less tiring, while the Bosch assistance helps keep a long day moving when the route turns steep. It is well matched to light singletrack and recreational descending, but regular enduro racing, big jump lines, downhill tracks and repeated bike-park laps call for a longer-travel machine with more specialised suspension.

Compare the current configurations by battery and equipment

The useful first choice is stored energy. The entry-level configuration has a 600 Wh PowerTube battery, while clearly named 800 Wh versions carry the larger battery. The 800 Wh option stores 200 Wh more energy, which can be valuable for longer, hillier days, but no battery capacity promises a fixed mileage: rider weight, climbing, temperature, tyre pressure, surface and assistance setting all have a say.

Next, decide whether practical equipment belongs on the bike from day one. Equipped versions arrive with integrated lights, mudguards, a rack and a kickstand, making them especially appealing for touring, everyday errands and rides that begin on wet lanes before heading onto a bridleway. The other configurations have frame mounts for a rack and mudguards, but those fittings are not the same as having the complete utility package supplied.

The 600 Wh base build is the fully detailed component reference, pairing its Bosch system with Shimano CUES LINKGLIDE 1x10 gearing, four-piston Tektro brakes, a RockShox Recon Silver RL fork and a RockShox Deluxe Select R shock. The 800 Wh and Equipped configurations retain the Gen 4 adventure platform, but their remaining component lists can differ between offers. Battery capacity and factory equipment are the dependable way to separate them before comparing the finer details.

Frame, wheel sizes and ride feel

An Alpha Platinum Aluminium frame, Boost thru-axles, guided internal routing and Trek's Active Braking Pivot form the backbone of the current platform. It is a substantial bike rather than a light, poppy trail toy, and that mass combines with the full-suspension layout to favour a planted, confidence-building character over rapid direction changes. On a long, rough route, that can mean less battering through your hands, feet and lower back.

Frame size changes more than reach. Size S uses 27.5-inch wheels and a 100 mm dropper on the fully specified 600 Wh base build, giving shorter riders a distinctly more compact package. Sizes M, L and XL use 29-inch wheels and have 170 mm droppers on that build. Choose the frame size for fit rather than with plans to swap wheel formats later, as Trek does not support an alternative wheel-size conversion.

Climbing is a major part of the Powerfly's appeal. The Bosch Performance Line CX system on the 600 Wh base build has a 250 W rated continuous output and leaves the factory at 85 Nm. Compatible Bosch smart-system installations may allow a software setting of up to 120 Nm where the drive unit, software and bike approval permit it. Higher assistance can make steep climbs easier, but it also uses more battery energy and can increase drivetrain wear, so the standard setting remains the sensible place to begin.

Charging, storage and wet-weather ownership

The base 600 Wh build weighs 24.58 kg in size M, including tubeless sealant and without inner tubes. That is quite manageable once rolling with motor assistance, but it is a meaningful consideration for stairs, ceiling storage and loading a vehicle. Ground-level storage is the easy win, and removing the battery before lifting can make handling less awkward. An e-bike-rated rack is the appropriate choice for car transport.

With the specified 2A charger, Bosch publishes approximately 9.1 hours to charge a fully empty 600 Wh battery and approximately 12.4 hours for an 800 Wh battery. This suits an overnight routine far better than a last-minute top-up before a ride. The 600 Wh base build also has a 136 kg maximum total weight, including bike, rider and cargo; rack capacity on Equipped versions needs to be treated separately from that total.

British winter riding brings ordinary e-MTB maintenance into focus. Keep an eye on brake-pad wear, chain wear, suspension pivots and the battery interface after muddy or wet outings. The CUES LINKGLIDE transmission on the detailed 600 Wh base build is a sensible mechanical setup for e-bike loads, but it still benefits from regular cleaning and timely chain replacement. A Bosch PowerMore 250 can be added for occasional longer rides, though it is not supplied and needs the correct 100 mm reversed cable and mounting hardware.

How Gen 4 differs from the previous Powerfly FS

A previous Powerfly FS 4 Gen 3 can still be a worthwhile lower-cost route into full-suspension e-MTB riding, but it is an older platform rather than the same current bike. Gen 3 used 100 mm of rear travel and 120 mm at the fork, an earlier RIB battery system and older geometry. Battery capacities across that family reached up to 625 Wh. Keep those bikes separate from the current Powerfly+ FS 4 Gen 4 when weighing up suspension, battery fit and frame features.