Trek Fuel EX 5 full suspension MTB review

This review first appeared in Issue 45 of BikesEtc magazine

At first glance, the Fuel looks an absolute stunner. Using the same aluminium frame found on Trek’s high-end models, it provides a good dollop of suspension, a well-proven design, and spot-on modern trail geometry.

Still, at this price there are compromises to be made. These see a non-tubeless wheelset and tyres fitted, and a dropper post absent.

Will this put a damper on its forward progress? Only the ride will tell.

Buy the Trek Fuel EX 5 bike from Evans Cycles

The frame

Working on the principle that the strongest way to join two points is with a straight line, the Fuel’s down tube is exactly that.

Branded the ‘straight shot’ design it makes the frame incredibly stiff. A ‘stop chip’ and keyed headset top cap prevent the fork from turning too far and whacking into the down tube.

As a failsafe, rubber bumpers are also applied to the side of the down tube.

Elsewhere, a flippable chip on the swingarm allows easy tuning of the bike’s geometry, slackening the head angle by half a degree and dropping the bottom bracket 10mm.

Trek’s long-serving Active Braking Pivot (ABP) suspension design keeps everything plush, even when yanking the brakes.

Driving a high-spec RockShox Deluxe RL air shock, it produces 130mm of travel that cleverly feels like more when pushed downhill, yet like less when riding uphill.

At the back of the frame, wider, boost standard dropouts also mean you can swap to 27.5in wheels and fat tyres if that floats your boat.

Groupset

Shimano’s Deore groupset may be budget, but it’s got all the most important features of pricier options.

Key among these is the clutch on the rear derailleur, which makes shifting more secure in rough conditions.

Gearing-wise the 10-speed 11-42t cassette is wide enough by itself, so paired to a twin-chainring Race Face Ride crankset the range is huge, making any hill climbable.

The lever design of the Acera brakes are a little clunkier than more expensive models but the power is solid.

Finishing kit

The quality of the finishing kit is high, although crucially the Fuel is missing a dropper post.

Even a basic one adds a phenomenal boost in efficiency and confidence. Fitting one will cost £100-200.

Taking care of steering are 730mm wide bars bolted to a 60mm stem. In the interests of stability we’d like to take a centimetre off the later and add a couple to the first.

The well-padded Bontrager Evoke saddle is likely to suit most riders.

Wheels

With its fantastic frame and suspension Trek has worked the Fuel’s spec very hard. However, there’s only so much you can shake the magic money tree before no more falls out.

This leaves the otherwise richly featured Fuel with a more basic wheelset. Not that there’s anything terribly wrong with them, it’s just that the hubs are a little workaday and the narrowish rims can’t be set up tubeless.

On the plus side, they’re light enough to not hold the bike back.

Equally the non-tubeless Bontrager XR3 tyres are quick rolling and decently grippy, even if their rubber compound isn’t the most naturally tacky. 

First impressions

With a frame that looks like it’s been stolen from a posher bike, the Fuel includes some interesting tech, foremost its unique straight down tube which requires limiting the turning radius of the fork.

In practice, the effect on steering is unnoticeable, and the frame seems extremely tough.

With a better than average shock and 10mm more travel than the norm it feels very slick.

However, medium-width tyres don’t over stress its gnarly side, ensuring the Trek rolls off easily.

Buy the Trek Fuel EX 5 bike from Evans Cycles

On the trail

The Fuel’s frame is plush and capable. The sort of thing you’d be happy to find yourself hacking down the side of a mountain on, somehow it also never makes itself a drag on the more prosaic bits.

Run with the shock wide-open, it tracks through the rough stuff and absorbs bumps both big and small without ever feeling out of its depth.

With a decent 130mm of suspension, it’s worth flipping the lever on the rear shock to stiffen it up for climbing.

This still leaves the suspension active enough to deal with unexpected impacts, but creates a better platform for pedalling.

It’s a very balanced bike in terms of talents. The tyres are all-rounders, too, predictable and striking a good compromise between speed and grip.

Rolling down sketchier bits, we did feel the lack of a dropper post, which would be our first upgrade.

With a wide 11-42t cassette, the Fuel could get away with a single chainring, although a double provides a useful extension of the range for crawling uphill or racing back down.

Handling

The Mino Link chip that sits at the top the Fuel’s seatstays can be flipped to slacken its geometry. Easy enough that you could do so in the car park before riding, it’s a great feature.

Unless you’re racing cross country, we definitely prefer the more confident and stable ride of the laid-back mode.

With such a preposterously stiff frame, the relative twang in the fork is more evident.

Running towards the end of their extension and packing in a centimetre more travel than most, it’s not a huge issue and only just noticeable when rattling through rocky sections.

Equally, a smidge of flex is detectable in the wheels when you throw them sideways. Still, this is really a compliment to the frame, rather than a slight on the components.

More annoying, given how ready the frame is to tear it up, are the narrow bars which stymie the Fuel’s ability to get rad.

Listed at 750mm, but actually two centimetres shorter, they leave the handling twitchy. Swapping them would be cheap, but it’s annoying nonetheless. 

RATINGS

Frame: Strong and light, with a clever suspension system. 10/10 
Components: Huge gearing range makes any hill climable. 8/10 
Wheels: Unexciting but they do the job perfectly well. 7/10 
The ride: Absorbs the bumps on even the roughest trails. 8/10 

Verdict: A great full-sus all-rounder with an innovative frame.  

Buy the Trek Fuel EX 5 bike from Evans Cycles

Geometry

	Claimed	Measured
Top Tube (TT)	595mm	595mm
Seat Tube (ST)	440mm	450mm
Reach (R)	450mm	450mm
Stack (S)	603mm	603mm
Head Tube (HT)	100mm	100mm
Head Angle (HA)	67.7	67.7
Seat Angle (SA)	66.2	66.2
Wheelbase (WB)	1,173mm	1,173mm
BB drop (BB)	30mm	29mm

Spec

Trek Fuel EX 5
Frame	Alpha Platinum Aluminium, Boost thru-axle, Knock Block steerer stop, 130mm travel, RockShox Recon Silver fork, compression and rebound adjust
Rear suspension	RockShox Deluxe RL, 130mm travel
Groupset	Shimano Deore M6000, 2x 10 speed
Brakes	Shimano Acera hydraulic disc
Chainset	Race Face Ride, 36/22t
Cassette	Shimano M6000 10-speed, 11-42t
Bars	Bontrager alloy, 15mm rise, 750mm width
Stem	Bontrager Rhythm Comp, Knock Block, 60mm
Seatpost	Bontrager alloy, 2-bolt head, 31.6mm
Wheels	Bontrager Connection 32h, sealed bearing hubs, Bontrager XR3, 29x2.3"
Saddle	Bontrager Evoke 1.5
Weight	15.25kg (M)
Contact	trekbikes.com