Trek Powerfly FS+ 6 Gen 4 review

Where the Powerfly FS+ 6 Gen 4 fits

The clearest match is long mixed-terrain rides and trail-centre days where an 800Wh reserve matters more than minimum weight. Compare the complete specification and available independent coverage before choosing a size or variant.

Motor, controls and UK legality

The available specification does not identify the motor precisely. The controls are Bosch Purion 200.

Bosch Performance Line CX supplies full-power support for sustained climbs and technical starts. It is a more forceful proposition than the HPR60 Fuel+, with a correspondingly less analogue-like ride.

The motor’s tunable modes and hill-oriented features broaden its use, but the strongest settings consume energy and accelerate wear. The 12-speed gearing helps keep cadence suitable.

For use as an electrically assisted pedal cycle in Great Britain, the maximum continuous rated motor power must not exceed 250W, assistance must cut out by 15.5mph and the pedals must be able to propel the bike. Check the label and delivered configuration rather than relying on a category name.

Battery, charging and realistic range

The listed battery is Bosch PowerTube 800 Wh, smart system. No numerical range is stated in the accessible listing; route, rider, weather and assistance level materially affect distance

An 800Wh removable battery is the defining upgrade over the FS+ 4 models, bringing meaningful margin for vertical gain and longer days.

Capacity is not free: it adds mass and takes longer to replenish than 600Wh. Real range still depends on support level, gradient, rider and conditions.

Use only the approved compatible charger, charge away from escape routes and stop using a battery that is damaged, swollen, leaking or unusually hot. Ask for the replacement-pack price and warranty conditions before the original battery becomes a problem.

Frame, fit and ride character

The frame specification is Alpha Platinum Aluminium, Removable Integrated Battery (RIB 2.0), tapered headtube, guided internal routing, Motor Armor, angle-adjust headset, Mino Link adjustable geometry, adjustable leverage rate, 34.9 mm seat tube, ABP, UDH, rack and mudguard mounts, Boost 148, 120 mm travel. Fork and suspension details are Fox AWL Rail HD, Rail 2.0 damper, tapered steerer, 44 mm offset, Boost110, 15 mm Kabolt axle, 180 mm direct mount, 130 mm travel; Fox Float Rhythm, 2-position damper, 210x50 mm. The tyres are Bontrager Gunnison Pro XR, Tubeless Ready, dual compound, aramid bead, 60 tpi, 29x2.40.

The e-bike-specific Fox AWL 130mm fork and Float Rhythm shock are a more controlled package than the entry Recon build, while preserving the platform’s versatile short-travel remit.

Shimano four-piston brakes and a 29in wheel format support confident trail use. This remains less descending-focused than the 160mm Rail+ family.

Brakes, transmission and everyday equipment

The bike uses Shimano 4-piston hydraulic disc, M6100 lever, M6120 calliper. Transmission is Shimano SLX M7100, 12-speed; Shimano XT M8100, long cage; Shimano Deore M6100, 10-51, 12-speed. The equipment information is Bontrager Line Dropper, 170 mm travel, MaxFlow, internal routing, 31.6 mm.

The SLX shifter and cassette with XT rear mech form a durable mechanical 12-speed setup. Removable battery design simplifies charging and replacement planning.

The large battery and full suspension make transport and stairs awkward. Owners should account for pivot, suspension and high-load drivetrain servicing.

What the published evidence tells us

The recorded price for this build is £4,049. Prices can differ by colour or size, and stock can change; a discount against a reference price does not by itself establish value.

The exact specification is verified through the seller and Trek’s current FS+ 6 page.

Independent Bikeboard testing of a current Powerfly platform praised the newer Bosch CX system’s quieter, smoother delivery. That test is relevant to the drive family but not proof of this exact suspension tune or complete build.

Advantages and disadvantages

The useful comparison is whether the complete build suits the regular route, storage and service plan. A premium motor cannot compensate for poor fit, while a modest component can be entirely sensible on the right type of bike.

• Advantage: Large removable 800Wh battery
• Advantage: Full-power Bosch CX motor
• Advantage: Upgraded Fox suspension
• Advantage: Dependable Shimano mechanical drivetrain
• Disadvantage: Large battery adds mass
• Disadvantage: Shorter travel than a Rail+
• Disadvantage: Mixed SLX/XT rather than a full premium group
• Disadvantage: Ongoing full-suspension maintenance

Buying checks and RideIn verdict

Confirm the exact product code, frame size, colour, battery capacity, assistance configuration and included equipment before paying. Ask who will handle electrical diagnosis, warranty labour and replacement components, then test the brakes, controls and fit before committing to regular use.

The most broadly sensible FS+ for long-range trail and adventure use, with the battery and suspension upgrades that matter more than electronic shifting.