Aluminium full-suspension electric mountain bike Trek Powerfly+ FS 4 grey: Bosch CX 600 Wh, 130/120 mm, 25.28 kg

Trek Powerfly+ FS 4 Mercury: the first step towards a full-suspension e-MTB

The Trek Powerfly+ FS 4 Gen 4 is an Alpha Platinum aluminium full-suspension electric mountain bike, powered by a Bosch Performance Line CX motor and a 600 Wh PowerTube battery. It offers 130 mm of travel at the front and 120 mm at the rear, and weighs 25.28 kg in size M according to Trek. Its Mercury/Dark Web finish pairs a light, mercury-like metallic grey with deep black sections.

Technical specifications

Who is it for?

For the hiker or occasional mountain biker who wants to discover the trails of the hinterland without dreading the climbs, and for whom a non-assisted mountain bike limited their rides. It also suits a couple where one partner rides less often and wants to keep up.

The LVR workshop view

Alpha Platinum, the aluminium behind the FS 4. Trek uses its Alpha Platinum aluminium for this frame, one notch below the Alpha NEXT Platinum of the alloy Fuel+ models. On this FS 4, two frame details matter day to day: the RIB 2.0 battery comes out in one piece for charging at home, held by a second latch that stops it from falling out, and the Motor Armor skid plate protects the Bosch motor from stones flicked up under the bottom bracket.

Put simply: the FS 4 puts the money where it matters on a first full-suspension e-MTB, namely the Bosch CX motor, front and rear suspension and four-piston brakes. The 10-speed CUES drivetrain and 600 Wh battery stay simple; they are also the two areas that set this version apart from its bigger siblings.

The Bosch CX is the benchmark motor for powerful e-MTBs: its assist builds progressively with your effort, which avoids jolts in hairpins. Like any e-bike type-approved in Europe, it delivers 250 W rated and cuts the assist at 25 km/h. On the rocky tracks around Béziers, the 120 mm rear suspension keeps the wheel in contact with the ground and the assist stays usable where a hardtail would bounce around.

The Bosch Purion 200 controller stays compact on the bar and displays the essentials: mode, battery level, speed. System updates go through the Bosch eBike Flow app on your phone, and we can also do them in the workshop during a service.

Which Powerfly+ FS should you choose?

Our take: at 25.28 kg in M, the FS 4 is the simplest Powerfly+ FS. For 220 g more, the FS 4 800 Wh gives you an extra 200 Wh of reserve; to move up to 12 speeds and Shimano brakes, the FS 5 drops to 24.58 kg.

Your questions

Why buy from LVR Cycles? As a Trek retailer in Béziers, we hand over your Powerfly+ FS 4 fully set up (suspension pressures, saddle height) with an introduction to the Bosch system and the Flow app.

Please note that the specifications may be changed without prior notice by the manufacturer, based on the availability of components and other factors.