Back in 2022, Trek was the launch partner for the ultra-compact TQ-HPR50 motor. The bike in question was the brand new Fuel EXe, and in many ways the TQ eco-system was a major step forward in terms of noise reduction, power delivery, display metrics and ultimately, discretion.

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The TQ-HPR50 motor isn’t much bigger than a bottom bracket

Two short years later, and the market for the best lightweight, mid-power e-bikes has changed beyond recognition. And with the TQ-HPR50 motor delivering a very light touch to the assistance level, can 50Nm of torque and a claimed 300 watts peak power convince anyone to part with their hard-earned cash? Especially now that there are much easier ways to “earn” your turns? A few examples of which also feature in this MBR SL E-Bike of the Year test. In short, maybe. But I’ll get to that later.

There are few clues that this Trek Fuel EXe 9.7 has a motor.

Frame and geometry

While the TQ motor has been reframed within the mid-power e-bike class, not much of anything has changed to the Fuel EXe since I last tested it. Travel on the frame is still 140mm, and all models use 150mm forks, even if I think the geometry and handling would be better with a 160mm travel fork fitted as standard. That’s unlikely to happen now though, as Trek recently introduced the Slash+ enduro bike, which also uses the TQ-HPR50 motor, albeit with a much bigger 580Wh battery.

High/Low geometry settings: You choose

But let’s get back to the Fuel EXe. Trek offers the bike in four frame size and you have the option of a full carbon or aluminium chassis depending on price. It comes with full 29in wheels as standard, but the frame has Trek’s signature Mino-Link asymmetric flip chips at the rocker-link assembly for geometry adjustment, or for partial correction of the BB height and angles when switching to an MX wheel format (27.5in on the rear). The bike ships in the low/slack setting, and unless you’re running the shock too soft or swapping to MX, I recommend leaving it there.

Trek’s signature ABP suspension on the 140mm Fuel EXe is super effective

The alloy frame mirrors the carbon one, and both use Trek’s signature ABP (Active Braking Pivot) suspension layout. In simple terms, having the rear most pivot concentric to the rear axle transforms the seatstay into a floating brake mount, which, in turn, allows Trek to define the braking characteristics more independently from the suspension behaviour. In fact, there’s a similar suspension configuration on the Orbea Rise LT in this test, but the shock is horizontal rather than vertical.

The vertical shock layout isn’t ideal for fitting a range extender

The main disadvantage of the vertical shock position on the Trek, at least on an e-bike, is that you can’t position the range extender low in the frame to help offset the additional weight, like you can on the Orbea, Specialized or Whyte. Why is this so important? Well in our range test, the TQ-equipped Trek with its 360Wh removable battery, had the worst range. But how bad can it be? How about 811m of vertical, compared to just over 1,200m on the Fazua-equipped Santa Cruz Heckler SL. Even the Specialized Turbo Levo SL level went further with its puny 320Wh battery.

With the compact TQ motor the Trek Fuel EXe 9.7 could easily pass for an analogue bike

Trek Fuel EXe 9.7 Need to know

• E-bike version of the Fuel EX
• Compact TQ-HPR50 motor with 50Nm / 300watts
• Removable 360Wh battery
• Full carbon frame with 140mm travel
• 29in wheels, with flip-chip for MX
• Fox Rhythm fork gets 150mm travel
• Optional 160Wh range extender
• Shimano XT/SLX 12-speed drivetrain
• Range: 811m vertical
• Weight 19.66kg (43.34lb)
• Sizes S, M, L, XL
• Currently discounted to £3,999

Motor and battery

TQ claims to have the lightest, quietest and smallest e-bike system in class. So let’s take a closer look at the numbers. The motor alone weighs a mere 1,850g, so it’s roughly 850g lighter than the full power Shimano EP801 motor on the Orbea Rise LT.  That alone is a considerable weight saving right there.

The 360Wh removable battery simply slides out the bottom of the down tube

And while TQ offers three different battery options; 250Wh, 360Wh, and 580Wh, the Trek Fuel EXe is powered by the removable 360Wh battery that weights 1,834g. The integrated 420Wh battery on the Orbea Rise LT weighs 1,950g, so again the TQ system offers Trek a 116g weight saving. In total then, the Trek has a 966g weight saving over the full-power Orbea, but at 19.66kg for the complete bike, the Trek is actually marginally heavier than the Orbea. So what’s going on? Well some of that extra fat on the Trek will be down to the lower end specification, but I also believe it’s due to the Trek Fuel EXe’s frame weight. Making the battery removable adds weight for sure, but the Trek also feels substantially more solid than the Orbea, even though it is a shorter travel bike.

The charging port is above the bottle cage on the down tube, and never quite feels like it’s fully closed.

The real kicker though, is that the Trek came dead last in the range test. It only managed 811m of vertical compared to 955mm from the Orbea, and 1,215m from the Cannondale Moterra SL. With such poor range, either TQ’s battery management software is overly cautious, or the dual harmonic design of the compact TQ motor isn’t very efficient. Either way, you’re going to want the range extender or a second battery with the Trek Fuel EXe. The 160Wh range extender is similar in size to a 500ml water bottle and costs almost £500. Also with the range extender fitted, the weight of the bike creeps up 20.76kg. So not ideal.

All of the metrics in one easy-to-read display.

In terms of power, the TQ-HPR50 motor offers three modes: simply called 1, 2 and 3. When in the lowest power setting, it’s actually hard to tell if the motor is even switched on. Seriously, it’s so quiet, and because it’s only providing 120 watts of assistance, it’s not much stronger than a good tailwind. So the first power setting is basically a limp mode. Even in full power, the TQ motor is only going to deliver 300watts at best. I was constantly monitoring the metrics on the top tube display during the range test, and it’s clear that the motor will give you a continuous output of 300 watts. So half that of the Bosch SX-equipped Whyte E-Lyte 150 RSX and Shimano EP801 bikes in our 2024 SL E-bike of the Year test.

Compact and robust, the TQ remote is totally sorted

The small handlebar remote switch feels really good when toggling between the different settings, and the monochrome display in the top tube has ANT+ connectivity for use with your smartphone. All of the ride metrics on the display are really easy to read, and there’s 10 bars and a percentage readout for battery life, which I was constantly monitoring. You can also use the remote to toggle between the different screens on the display, or activate walk mode.

Suspension

When I last tested the Fuel EXe, it was the all-singing-all-dancing 9.9 XX1 AXS model and I complained that the RockShox shock was seriously over-damped, especially in rebound. Switching to the Fox Float X on the EXe 9.7 has totally rectified that, and I’m now mid-range on rebound, which is exactly where an 85kg rider should be. Best of all, the 140mm rear suspension, and overall feel of the bike, is every bit as enduro-focused as before.

X marks the spot for a easy and affordable suspension upgrade.

With no sag gradients on the body of the Fox shock, setting the sag on the Trek is tricky. So you need to remember that the shock stroke is 60mm, and work backwards from there. Set it too soft and the suspension will feel harsh. I found the sweet spot to be around 28% sag. Being a Performance level shock there’s no low-speed compression adjuster, but as one of our viewers kindly pointed out, you can remove the plastic cover on the reservoir of the shock and retrofit a dial for fine tuning the low-speed compression damping. Instantly upgrading the shock to Performance Elite level for under £40. Bonus.

The Fox Rhythm fork get 150mm travel, but not the latest friction-reducing tech

The basic 150mm travel Fox 36 Rhythm fork on the Trek Fuel EXe doesn’t get the snazzy lube channels, or bleed ports, found on the higher-end Fox 36 forks in this SL e-bike test. It still has a smooth, plush action though, even if it doesn’t have the same level of support as the Grip 2 and Grip X damped forks.

A 160mm travel fork would help boost the front-end height on the EXe.

And that’s the primary reason why I think the Fuel EXe would benefit from a 160mm travel fork. With the current setup, I was running the fork firmer to get the support I wanted, and the stem at full height, just to keep my weight more centred when descending.

Components

From the get-go I had issues with the Shimano Deore four-piston brakes. The rear brake pumped up on descents and both brakes exhibited the usual variable bite point that plagues a lot of Shimano’s brakes. A quick bleed eliminated the pump, but the lever feel was always temperamental, even if the brakes had ample stopping power thanks to the big 203mm rotors.

Once again I had issues with the Shimano hydraulic brakes on the Fuel EXe.

There’s a fast, smooth action from the 170mm TranzX dropper post, and while I tend to like a flatter saddle profile, there’s no upsweep at the rear of the Bontrager Arvada saddle, so there is nothing to push against on steeper climbs. And I wanted it, because the lower power of the TQ motor means I would run out of gears pretty fast as the gradient increases, which makes the riding position on the EXe every bit as critical as on an analogue bike. So it’s a good thing that Trek has nailed the seated climbing position with the generous 482mm reach, steep 77.2º effective seat tube angle, and 440mm chainstays.

The low-power TQ motor put less strain on the fragile Shimano XT/SLX drivetrian.

The Shimano XT 12-speed derailleur bolts into a universal derailleur hanger, and overall the shifting performance of the Shimano XT/SLX mix of kit was decent enough. Probably because the lower power TQ motor is not putting the same loads though the chain as the other more powerful bikes in test.

Fast, crisp engagement from the 12-speed Bontrager freehub.

There’s also super-fast 108 point pick-up with the Bontrager rear hub, and while swapping the stock 2.5in Bontrager XR5 Team Issue tyres for our Continental Kryptotal control tyres proved to be a bit of a wrestling match – due to the Bontrager TLR plastic tubeless rim strips making for super tight fit – once the tyres were on, getting them inflated with a floor pump was super easy.

Performance

With the least power and the worst range, it’s easy to hate on the Trek Fuel EXe 9.7. But those two things aside, it’s actually a pretty decent bike. The motor had a really smooth pedalling action, and the frame feels more solid and capable than its 140mm travel suggests. And, if the Trek Fuel EXe was your first ever e-bike experience, you’d be pleasantly surprised.

Climbing

Hit a steep climb and I’d have to rapidly shift up across the 12-speed Shimano cassette to keep the 170mm cranks turning. But as I mentioned earlier, the riding position on the EXe is really good, so even though I was breathing harder than on most of the other bikes, I had no problem keeping the front end down to navigate climbs.

You’ll need plenty of muscle power on the Trek Fuel EXe.

Sure, there’s no overrun from the TQ motor, so when I stopped pedalling, even for a split-second to hop up a rocky step, or over a fallen tree, and the bike stalled, instantly robbing me of my hard-fought momentum. Also, the 300 watts peak power limits the climbs I could realistically tackle on the Fuel EXe. Yes, the climbing performance is still a big step up from an analogue bike, but with half the power of the Bosch SX motor, I struggled to keep up on the climbs, even with the smaller 32t chainring and longer 170mm cranks, especially when I was riding in a lower power mode to help conserve the battery life.

Descending

Hit the descents and the Trek Fuel EXe isn’t going to get left behind. Well, at least not once I’d swapped in our Continental Kryptotal control tyres. The riding position, suspension, and overall feel of the full carbon chassis gave me the confidence to really press on. And with the lighter tune on the Fox Float X shock, it’s now really easy to unweight the bike and move it around. Best of all, it doesn’t seem to have lost any of its raw straight-line speed. So, for a 140mm travel bike, the Trek Fuel EXe really has enduro vibes about it.

Poppy and playful, the Trek Fuel EXe 9.7 is easy to get airborne.

A silent bike is a fast bike, so it helps that there’s zero rattle from the TQ motor when coasting. Which just makes the cable rattle even more annoying. So the first thing I’d do is take the EXe back to the dealer and get it to shorten every cable on the bike to eliminate the noise. I’d also get a second battery. Because, let’s face it, unless you’re really strapped for time, 811m of vertical in full power mode isn’t going to cut it. Also, given the location of the range extender, half way up the down tube, I really think a second battery is the way to go, as it will instantly double the range without messing with the weight distribution of the bike. Especially since, at around £550, they are only a bit more expensive than the range extender.

Full enduro send, even though it’s only got 140mm travel.

With the fork slightly over-inflated, and 28% sag on the rear shock, the suspension on the Trek Fuel EXe felt really well balanced. The 29in wheels definitely took the edges off the bumps on some of the faster, rougher trails, but I’d still expect a higher specification fork on a bike costing £7.6k. I’d also want better tyres and brakes, and ideally more power and range too. I’ve since seen the Trek Fuel Exe 9.7 discounted to £3,999, which make it an incredible bike for the money, but too late to change the 6 rating.

Trek’s Fuel EXe 9.7 has the ride quality, but it desperately needs more power and better range