Trek Fuel EX 9.8 27.5 – first ride review

Mid-wheel rerub rings the changes

Our rating 
4.0 out of 5 star rating 4.0
GBP £3,800.00 RRP | AUD $5,899.00 | USD $5,249.99

Our review

A worthy contender, with dialled angles, dependable kit and a new damper that performs without much fuss
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Trek’s 120mm (4.7in) travel Fuel EX range is being split into 650b and 29in wheeled families for 2015 – “same trail, different riders” is how the the manufacturing titan describes the division. The 9.8 27.5 is the top UK ‘mid-wheeler’, with playful geometry and new suspension technology that has its roots in Formula 1 racing.


Frame and equipment: motorsports pedigree

Trek’s OCLV Mountain Carbon makes up the majority of the chassis, with alloy used for the chainstays. The new Fuel EX uses the same Active Braking Pivot design as its predecessors, based around a concentric rear axle pivot and floating shock, and pairs it with a proprietary dual-chamber DRCV version of Fox’s Float CTD shock.

On the top models, the suspension technology has been taken a step further, thanks to a new partnership with motor racing specialist Penske Racing Shocks. The result is a regressive damper that uses a proprietary air spring and ‘RE:activ’ valve to provide a firm pedalling platform that quickly drops away when the trail turns rough.

Formula 1 derived internals take the shock’s platform damping to another level:
Sterling Lorence

Formula 1 derived internals take the shock’s platform damping to another level

The Fuel EX 9.8 27.5 comes with a full complement of Shimano Deore XT kit, including a double crankset and the very reliable brakes. The Fox shock is matched with a Performance series 32 Float fork up front. Trek’s house brand, Bontrager, supply the wheels, tyres and cockpit kit. The Rhythm Comp wheels and tubeless-ready XR3 Expert tyres seem like a good match, though the 720mm handlebar is on the narrow side.

The ride: a potent grade of Fuel – but more travel would be welcome

The 650b incarnation of the Fuel EX bears little in common with its 29in siblings, and even less with its 26in ancestors. Its DNA, and consequently its ride feel, is most closely related to the 140mm (5.5in) travel Trek Remedy. “Remedy Light” would be a more apt name for this bike.

If there’s a line to be drawn between long-travel XC bikes and short-travel trail bikes, the Fuel EX 9.8 27.5 sits firmly on the trail side of things. With a 68-degree head angle, 338mm (13.3in) BB and 432mm (17in) chainstays, it’s quite a lively ride, and the geometry lends itself to high-speed high jinks. We frequently found ourselves wishing for more than 120mm of front travel – a burlier build option would be welcome.

This fuel lends itself to high-velocity thrills, but its 120mm front travel feels a little meagre:
Sterling Lorence

This Fuel lends itself to high-velocity thrills, but its 120mm front travel feels a little meagre

When it comes to pedalling, the ABP design definitely benefits from the use of platform damping. The effects of the new RE:aktiv valve are most noticeable in the shock’s ‘Climb’ setting – where it provides a very firm platform until you encounter a high-velocity impact, such as a square-edged rock – less so in ‘Trail’ and nearly absent in ‘Descend’. We found ourselves leaving the shock in ‘Climb’ on smoother trails and toggling to ‘Trail’ for mixed terrain.


Unlike inertia valve technology, the transition from the platform to fully open is smooth and seamless – we didn’t experience any initial harshness, nor did the suspension blow through its travel with the first impact.

Product Specifications


Name Fuel EX 9.8 27.5 (14)
Brand Trek

Brakes Shimano Deore XT
Cranks Shimano Deore XT
Fork Fox 32 Float CTD FIT Performance, 120mm (4.7in) travel
Frame Material OCLV Mountain Carbon w/ alloy chainstays, 120mm (4.7in) travel
Front Tyre Bontrager XR3 Expert 27.5x2.35in
Handlebar Bontrager Race X Lite Carbon Riser, 720mm
Rear Shock Fox Float CTD Performance w/ DRCV and RE:aktiv
Rear Tyre Bontrager XR3 Expert 27.5x2.5in
Saddle Bontrager Evoke 3
Seatpost RockShox Reverb Stealth
Stem Bontrager Race X Lite, 70mm
Weight (kg) 12.2
Wheelset Bontrager Rhythm Comp wheels
Year 2014
Weight (lb) 26.8