9 Lessons We’ve Learned About Our 2020 Trek Fuel EX Test Bike

The not-so-minor details


2020 Trek Fuel EX 9.8


Trek Bicycles Australia



$6,999 AUD (stock build)


12.9kg (current build)


- Hugely capable for a 130mm travel trail bike
- The stiff & responsive chassis
- Supremely balanced & versatile handling
- The suspension is so plush and well controlled
- Improved pedal efficiency and support
- Lifetime frame & carbon wheel warranty


- Poor-fitting downtube trapdoor
- The stock Bontrager dropper post is sluggish and sloppy
- Carbon wheels are quite harsh

Wil Bids Adieu To The 2020 Trek Fuel EX 9.8 Long-Term Test Bike

When I think of the archetypal trail bike, Trek’s Fuel EX is one of the first names that springs to mind. And it should do, since it’s been kicking up the dirt for more than a few years. Launched all the way back in 2005 as the trail-offshoot of the Top Fuel race bike, the original Fuel EX was equipped with a generous 100mm of suspension travel, 26in wheels (of course), and it had quick releases front and rear. Since it was born during a time where we wanted as many gears as possible, it also had a 3×9 drivetrain. After 15 laps around the sun though, things have changed just a little.

The 2020 Trek Fuel EX is now the 9th iteration of the platform. It’s still a trail bike through-and-through, but compared to the original it’s got a lot more muscle. Having hit its teenage years, the Fuel EX is bigger on travel, bigger on wheelsize, bigger on geometry, and it’s equipped with almost every conceivable mod-con there is available today. There are 15 less gears though.

2020 trek fuel ex 9.8 red
For 2020, Trek has launched the 9th iteration of the Fuel EX platform. Still a trail bike, just A LOT more capable!

Flow’s Fearless Leader, the Marvellous Mick Ross, went to the launch for the Fuel EX last year, and came away thoroughly impressed. Shortly afterwards, we received a Fuel EX 9.8 test bike for a proper long-term review on Aussie soil. After the first six weeks together, I posted my initial thoughts and suspension setup notes in a mid-term review. I’ve been riding the heck out of it since, and I’ve also been using it to test a variety of other components, including Curve’s carbon Dirt Hoops, the Shimano SLX 1×12 drivetrain and Shimano SLX 4-piston disc brakes.

To say we’ve gotten to know each other over the past six months would be a hefty understatement. We’ve had our disagreements, which you’ll read about in more detail below, but I’ve also learned a lot. And so with Baby Blue due to head back to the mothership, I thought it would be an appropriate time to detail those learnings before we part ways. For now at least.

2020 trek fuel ex 9.8 wil harcourt
We’ve been testing a Fuel EX 9.8 on home trails for the past six months.
2020 trek fuel ex 9.8
Being a long-term test bike, the Fuel EX has had a load of various parts strapped to it for separate reviewing.

Before going any further, we’ll stipulate that this bike first started out as a stock Fuel EX 9.8. If you want a refresher on what that looked like and what parts come on it for the $6,999 sticker price, check out the first look story here. Otherwise, read on to see how it’s currently setup.

2020 Trek Fuel EX Current Build Specs

2020 trek fuel ex 9.8
The Fuel EX is currently wearing a OneUp cockpit, DMR Deathgrips and a Funn dropper post.
2020 trek fuel ex 9.8
The new frame is noticeably stiffer, and that’s complemented by the big Fox 36 fork.

1. This Is Trek’s Stiffest Fuel EX To Date

No doubt about it, the latest Fuel EX chassis is the most robust of the lot. I’ve ridden every iteration of the Fuel EX since 2009, and it’s gotten bigger and burlier with each redesign, but this latest model takes the beefcake. The OCLV full carbon frame on the 9.8 (also used on the cheaper 9.7 and more expensive 9.9 models) is huge in every way. Everything about it is oversized, including that massive Straight Shot downtube.

Push it into a high-speed berm, and it simply doesn’t flinch. At all.

For 2020, the Fuel EX skips the Full Floater suspension design in favour of a fixed lower shock mount, much like the Remedy and Slash before it. Trek has finally ditched front derailleur compatibility, which has allowed the main pivot to be built much wider than before. The result of these two changes is a big lift in chassis stiffness. From the plump tapered head tube, down to the 92mm wide bottom bracket shell, and all the way back to the Boost 148x12mm ABP dropouts, the Fuel EX delivers a stout and responsive feel. Push it into a high-speed berm, and it simply doesn’t flinch. At all.

Also amplifying the Fuel EX’s stiffness is the Bontrager Line Carbon 30 wheelset. The carbon rims use the same mould that Bontrager has been using for quite a while, with a 29mm internal width and a 30mm deep profile. Along with the 28 J-bend spokes and high-flange hubs, it’s a very stiff and responsive wheelset, but it isn’t exactly compliant. Being on the lighter side however, I’ve found them to be quite harsh, with a lot of deflection when barrelling through rock gardens. This was made very apparent during some back-to-back testing with both the Curve Dirt Hoops and DT Swiss EXC 1200 wheelsets – both of which also use carbon rims, but ride significantly smoother.

2020 trek fuel ex 9.8 bontrager xr4 team issue 29x2.6in tyre tire
Bontrager’s Line Carbon 30 wheels are stiff and responsive, but in our testing, they certainly aren’t what you’d call compliant.

Up front, the Fox 36 fork is an excellent accompaniment to the Fuel EX. Even aesthetically, it’s just a better match for the mahoosif frame. Unfortunately the 36 is only found on the 9.8 and 9.9 models, with the cheaper Fuel EX’s coming with a slimmer 34. It’s not that the 34 is a bad fork, we’re big fans here at Flow, it’s just that if you’re going to really push this bike to its outer limits, then you’ll appreciate the extra strength up front. And I say that as a 68kg weakling – bigger folks will notice the improvement in tracking even more.

2. It’s Also The Most Efficient Too

This bike has a lot more surge at the pedals than its predecessor. The stiffer chassis and carbon wheels no doubt help with the responsive feel under power, but the new Fuel EX is inherently more efficient too. According to Trek, there is 10% more anti-squat through the travel compared to the 2019 Fuel EX. On top of that, the move away from the Full Floater suspension design means there’s more spring support from the shock too, so you don’t have to rely on the RE:aktiv damper to provide efficiency. If you’ve ridden previous EX’s and found them to feel a bit dumpy or wallowy, then you’ll be impressed with the more pert performance of the new 2020 model.

The improved pedal efficiency and spring support means I’ll use the Open position about 90% of the time, only flicking into Trail or Firm modes for smooth climbs or long road sections.

On the previous Fuel EX, I would typically ride with the shock’s blue compression lever set to the middle Trail position about 90% of the time, flicking it into the Open position for rockier descents. With this Fuel EX however, that ratio has flipped. The improved pedal efficiency and spring support means I’ll use the Open position about 90% of the time, only flicking into Trail or Firm modes for smooth climbs or long road sections.

2020 trek fuel ex 9.8 harcourt wil
With the new 1X specific frame, Trek has tuned the suspension kinematics to provide more support and better pedal efficiency.
2020 trek fuel ex 9.8
The Fuel EX delivers 130mm of rear travel, though for the 2020 model the Full Floater linkage has gone in favour of a stiffer fixed shock mount and a wider main pivot. Anti-squat increases by around 10%.
2020 trek fuel ex 9.8 thru-shaft re:aktiv shock
Compared to previous Fuel EX’s we’ve tested, the new model is much better behaved in the Open mode.

While neither approach is right or wrong in my opinion, the improved efficiency does make the RE:aktiv damper somewhat redundant. Riding choppy off-road sections, either uphill or downhill, you’re much better off leaving the shock in the Open mode. There’s otherwise too much feedback through the suspension, and traction suffers. It isn’t quite as drastic as Specialized’s Brain damper, but it’s uncomfortable enough that I’d recommend running the shock wide open on rocky terrain.

Oh, and one other thing – the Firm mode doesn’t totally lock out the rear suspension. Unlike the fork, which has a rock-solid lockout, you’ll still get shock movement when pedalling hard out of the saddle. On the flipside, it also means the suspension will still work if you forget to flip the blue lever back to Open before you hit a descent.

3. The New Suspension Design Isn’t Quite As Floaty

Though Trek says the leverage curve is almost identical between the 2019 and 2020 Fuel EX designs, the new bike has traded up some of the floaty-ness that we loved about the old model. This tradeoff has been made in favour of greater mid-stroke support, which provides the pert pedalling performance mentioned above. It also gives the rider more feedback in peak-load scenarios, like pummelling through a berm at high speed, or pushing off lip on the trail. On modern flow trails, this bike is simply faster and more responsive.

However, on really turbulent sections of trail, there isn’t quite the same marshmallow-bottomlessness that the suspension on the old Fuel EX oozed so effortlessly.

Despite using full travel regularly, I can’t recall one occasion where I hit full bottom-out – it’s smooth and progressive as you get towards those final millimetres. However, on really turbulent sections of trail, there isn’t quite the same marshmallow-bottomlessness that the suspension on the old Fuel EX oozed so effortlessly. It doesn’t feel quite as ‘deep’ as the previous bike, with a bit more feedback from the trail. This is more noticeable on my home trails, which are natural and very old-school, admittedly with a distinct lack of soil and an over-abundance of rocky chunder.

It is still very smooth compared to the competition, particularly on this 9.8 model with the fast-moving Thru Shaft shock damper. Since there’s no IFP with the Thru Shaft design, the shock is able to react very quickly, with minimal hesitation in both directions. Along with the stronger support, the suspension on this bike is very well balanced for contemporary trail riding.

4. Confidence Levels Are At An All-Time High

The Fuel EX has always punched above its weight. For a 130mm travel trail bike it is hugely capable, with its supple suspension and muscly chassis delivering oodles of confidence.

The suspension is richer and more effective than Giant’s Trance 29, the chassis feels more solid than the Specialized Stumpjumper, and the handling is far more planted than the Canyon Neuron. I am yet to ride the new Norco Optic (we have one on the way), but I’m eager to see how that compares.

2020 trek fuel ex 9.8 dt swiss exc 1200 carbon wheels
The slacker head angle, chunkier fork and reduced offset provide a big boost in front-end stability. Trek hasn’t gone so slack to make the steering floppy though. It’s a nice balance.

In particular, the front end feels like it’s from a much bigger bike. The 36mm fork chassis feels especially stout in this short offset and 140mm travel guise, and the 66° head angle kicks out the front wheel far enough, without suffering from chopperitis.

Directly compared to the 2019 Fuel EX, the new bike has a lot more trail – 119mm vs 103mm, about a 15% increase. That means there’s more inherent damping to the steering, with a stronger willingness for the front wheel to stay pointing ahead. It keeps things steadier at high-speed, without the floppier steering of a slacker head angle on the flats and climbs.

So if you wanted to push into mini-enduro territory, which this bike is plenty capable of, you could buy a 150mm air shaft to jack up the Fox 36.

Worth mentioning is that Trek has cleared this frame to run up to 150mm of travel up front. So if you wanted to push into mini-enduro territory, which this bike is plenty capable of, you could buy a 150mm air shaft to jack up the Fox 36. And while you’re at it, you could always throw in a GRIP2 damper too if you wanted to go nuts. The Fuel EX is certainly ready for it if you are.

5. The Geometry Is Spot-On, And Easily Adjustable Too

I like that Trek didn’t go overboard with the geometry update for the new Fuel EX. It gave it all the usual nip-tucks, but it didn’t push things out so far as to water down this bike’s all-round capabilities.

The steeper 75° seat angle is a noticeable improvement on the climbs, and for me as a 175cm rider on a Medium frame, I wouldn’t want it much steeper than that. Riders with shorter femurs may disagree, but I like how comfortable this bike is to ride on mellower trails and on the long flattish road commute to and from the trails. The bike is quite roomy with a 440mm reach and the 50mm long stem, so there’s plenty of space to get comfortable.

2020 trek fuel ex 9.8 wil harcourt
The 440mm reach on our Medium test bike is spot-on for this kind of trail bike. It’s comfortable and easy to manage.

You can steepen the angles by half a degree by flipping the Mino Link – a small alloy flip chip found at the top of each seatstay. It’s a very easy adjustment to make on the side of the trail, with only a 5mm hex key required. Flipping the Mino Link into the ‘High’ position also lifts the BB by 6mm, which doesn’t sound like much, until you remember that crank arms are sold in 5mm increments.

Given how easy it is to flip on the side of the trail, it’s a cool feature to experiment with.

I tried both settings regularly, though truth be told, there isn’t a drastic difference between them. Since I have a lot of tech climbs on my local trails, where rainfall has eroded gullies and filled them with loose baby-head sized rocks, the extra pedal clearance from the High position has been my go-to setting. I can notice a bit more pressure on my hands due to the steeper seat angle, but otherwise the bike still descends fantastically, and it also carves corners a little more assertively. Given how easy it is to flip on the side of the trail, it’s a cool feature to experiment with.

2020 trek fuel ex 9.8 mino link
Flipping the Mino Link will raise the BB by 6mm and steepen the angles by half a degree. It’s an elegantly simple design that takes all of a minute to adjust trail-side.

6. Traction Levels Are Off The Charts

Alongside the Fox 36 and thicc frame, the Fuel EX looks even meatier with its big 2.6in rubber. It’s a bold decision to spec such high volume tyres on a mass production trail bike, but remember that the industry was going ga-ga for 2.8-3.0in plus tyres not long ago (where did they go by the way?).

We’re longtime fans of Bontrager’s trail tyres here at Flow, and the XR4 is even better in this big 2.6in size. It’s a versatile tread pattern that performs well in a very wide range of conditions, from off-camber turns on baked-out hardpack through to high-speed charging across loose rubble. With the exception of the gloopiest mud and greasiest clay, these tyres can handle it. And despite having written-off the rear tyre on nearly every test bike over the past six months, I’m still yet to puncture these XR4s. Just as my fingers have typed that out, I know exactly what’s going to happen now though…

The high volume means you’ll want to run these at lower pressures to get the most out of them. Depending on the terrain, I’ve aired them up as low as 18psi on the front and as high as 22psi on the rear. Alongside the supple suspension, they’re a big contributor to the Fuel EX’s overall damping qualities, and they back up the balanced handling with impressive cornering bite.

7. Tyres Make All The Difference

Of course nothing comes for free. The extra damping and traction from the big XR4s mean they’re not the fastest rolling rubber. At 916g & 926g (confirmed) I wouldn’t call them heavy given their size, but there’s obviously more mass here compared to skinnier trail tyres.

To add a bit of zip, I setup the Fuel EX with a pair of 2.4in Pirelli tyres; a Scorpion M up front and a Scorpion R out back. Despite being about the same weight, the Scorpion tyres were significantly faster rolling due to their shallower tread profile and smaller footprint.

But at the very least, a skinnier and lower profile rear tyre will improve this bike’s rolling speed, and it’ll also give you a little more feedback too.

For more cross-country type riding, a tyre change makes a big difference to the bike’s speed, efficiency and even handling too. Along with flipping the Mino Link into the High position, and firming up the rear shock’s compression damping, the Fuel EX becomes better suited to long distance applications. If you really wanted to boost its versatility for tackling multi-day events like the Port to Port without having to invest in a secondary race bike, you could even fit a set of lighter wheels, which Mick is a big fan of.

But at the very least, a skinnier and lower profile rear tyre will improve this bike’s rolling speed, and it’ll also give you a little more feedback too. I’ve recently shifted back to running the XR4 on the front, and there’s a 2.3in Maxis Minion DHR II on the rear, which gives a slightly firmer and more direct feel to the back end for those who might find the 2.6in tyres over-damped. I’ve also been testing this bike with a set of DT Swiss EXC 1200 wheels, which we’ll be publishing a full review on soon.

8. It Could Do With Some Refinement

While we’ve enjoyed a mostly fruitful relationship over the past six months, I have had some disagreements with our Fuel EX 9.8 test bike.

The stock Bontrager dropper post is sluggish, and over time it’s developed both fore/aft and rotational play. Given there are plenty of good droppers out there these days, I’d expect it to be better than this. There’s currently a Funn UpDown dropper post in its place, which has been a lot more solid.

As it stands, if you’re bombing high-speed descents in top gear, the chain clangs and echoes through the cavernous carbon frame, emulating the sensation of a loose shock pivot.

The biggest annoyance though has been the excessive chain slap. This is a problem when you’re in the smaller sprockets on the cassette, where the chain hovers mere millimetres above the chainstay. Trek has likely kept the chainstays symmetrical for stiffness, but the drive-side really should be lowered to provide more clearance with the chain. As it stands, if you’re bombing high-speed descents in top gear, the chain clangs and echoes through the cavernous carbon frame, emulating the sensation of a loose shock pivot. Perhaps a thicker chainstay guard or a device like the STFU guide could help Fuel EX owners.

2020 trek fuel ex 9.8 shimano slx 1x12
Chain slap is an issue on this bike.

This means the rear hub ‘floats’ in between the dropouts while you try to locate the axle.

I’ve also found fitting the rear wheel to be more difficult than it should be, as the hub end caps are a smaller diameter than the dropouts. This means the rear hub ‘floats’ in between the dropouts while you try to locate the axle. It’s a bit like fitting a regular front hub to the oversized Torque Cap dropouts on a RockShox fork.

It still fits of course, but it’s a bit faffy, even more-so when there’s a chain and derailleur to contend with. The only reason I can see for the design is if Bontrager and/or SRAM is going to release a rear hub with oversized end caps to fit the oversized dropouts. That’s only a guess though – we’ve had zero clues from either company.

I’ve also had issues with the downtube trapdoor – something I flagged in the mid-term review. The door itself works fine, and the latch is very user friendly whether you’re wearing gloves or not. However, the fit on our trapdoor is slightly loose, and that leads to rattling when you’ve got a full water bottle in the cage.

Trek responded by saying this is the first time it’s heard of the issue, though we’ve spoken with a few different Trek dealers in Australia who have said otherwise. The severity of the play varies from bike to bike, and anecdotally we’ve heard that it’s less of an issue on newer production bikes – perhaps a thicker rubber seal has helped to tighten the fit between the frame and the door, or the tolerances have simply improved.

Still, I’d prefer to have not encountered the problem at all on a $7K bike.

I ended up sticking on some tape to the underside of the door, which has helped limit the movement and noise. And it’s worth noting that the plastic doorframe can actually be removed from the carbon downtube entirely via four bolts, so it could be replaced under warranty if the movement was bad enough. Still, I’d prefer to have not encountered the problem at all on a $7K bike.

The downtube storage is still a good idea though, and I like that I can have the essentials stowed away in the bike so I don’t have to remember them every ride. The soft tool roll that Trek includes with the bike is pretty neat, though it’s a very tight fit for a 20gm CO2 cylinder and a pair of tyre levers in the designated pockets. You’ll also need a lightweight tube – a standard tube is too thick and bulky to fit into the sleeve. Fitting the loaded tool roll into the frame can take some careful negotiation, and removing it requires a bit of force – enough that the red pull-tag has unfortunately ripped off.

2020 trek fuel ex 9.8 storage integrated
I love the concept of the downtube storage, but our test bike had a sloppy fit. It’s possible to replace both components though, and Trek says this would be covered under warranty.

9. There’s A Proper Lifetime Warranty On The Frame AND The Wheels

Being a Trek, the Fuel EX 9.8 frame comes with a lifetime warranty for the original owner. For 2020 models onwards, this warranty now (rightly) covers the swingarm as well as the mainframe. Also new is that if you end up selling your bike, the purchaser of your second hand bike will still have access to a limited frame warranty – specifically three years of coverage from the original date of purchase from the retailer. You can check out the specifics of Trek’s new warranty policy here.

And it’s another big advantage of buying a bike through a bricks & mortar shop rather than online.

Furthermore, Trek also offers a ‘Carbon Care’ program, which means if you damage the carbon frame from a crash, or you scratch your pedal cleat over the top tube, Trek will offer you a replacement part or frame at a discounted cost. This is something you’ll need to do through your local Trek dealer, and it’s another big advantage of buying a bike through a bricks & mortar shop rather than online.

2020 trek fuel ex 9.8
Like the Fuel EX’s frame, Trek’s warranty policy has been beefed up for 2020 to be one of the best in the business.

Something I didn’t know is that the Bontrager Line Carbon 30 wheels are also covered by a limited lifetime warranty, which basically covers you against any manufacturing defects. What’s really cool is that you also get a 2-year crash replacement warranty that covers you for any accidental damage. Misjudge a gap and blow out the tyre and crack the rear rim on a sharp pointy rock? Yep, that’s covered. You’ll either get a free repair or replacement, even if it was just you being stupid. Pretty insane huh? If you don’t believe me, check out the deets on Trek’s Carbon Care Wheel Loyalty Programme.

Aside from the aforementioned harshness, I haven’t encountered any issues with the stock Line Carbon 30 wheelset. At 1908g, they aren’t light wheels, but I do like the fast 54T rear hub engagement, and the TLR rim strips provide an exceptionally tight and reliable seal with tubeless tyres. While I’d personally prefer a set of high quality alloy wheels from a compliance perspective, it’s nice to have the added insurance of Bontrager’s 2-year guarantee on the carbon wheels.

2020 trek fuel ex 9.8
If you’re after a versatile and confidence-inspiring trail bike, they don’t come much more well-rounded than this.

Flow’s Verdict

With this latest iteration of the Fuel EX platform, Trek has delivered the most capable one yet. Indeed I’m struggling to think of a 130mm travel bike that’s as versatile and up-for-it as this.

In its stock configuration, the Fuel EX 9.8 is a brawny trail bike that’s ready for the most technical singletrack you can throw at it. The suspension is highly effective, the front end is thoroughly planted, and the high volume tyres provide exceptional damping with corner-ripping traction. Extend the fork to 150mm, fit a tubeless insert in the back and some stiff-casing tyres, and you’d be ready to front up to an enduro event. With the exception of double black diamond trails at the bigger bike parks, there really isn’t a lot of terrain in Australia that this bike won’t handle.

With its improved pedal efficiency though, there’s a snappier bike lurking beneath the chubby rubber. Flip the Mino Link into the High position, fit some lighter tyres, and it’s possible to set this bike up for more dedicated mile munching. If you wanted to go further, then a set of lighter wheels would really turn it into two-bikes-in-one for entering a handful of events each year like the Port to Port.

It’s certainly a comfortable bike for all-day pedalling, something that’s been achieved by not over-cooking the angles. While Trek has pushed a lot of the mod-con buttons, and improved the Fuel EX in the process, it hasn’t mashed the whole keyboard to push things so far out of whack to reduce the comfort and fun factor on less gnarly singletrack.

And that’s where the beauty of this bike lies. There’s nothing overtly weird or radical about it. It’s immediately comfortable out of the box, and the approachable handling means it’s suitable for a wide range of riders and terrain. The result is a terrifically balanced bike that inspires confidence without asking a whole lot from its pilot. Which to me feels like the archetypal trail bike.

2020 trek fuel ex 9.8 wil harcourt
After six months of testing, it’s time to finally say goodbye to the Fuel EX. Well, for now anyway…

Mo’ Flow Please!

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