The e-MTB market is certainly changing. While at one point we would see enormous, weighty beasts, with fat batteries and motors, we’re now seeing a new sub-genre of MTBs and e-MTBs.
Specialized has been at it with its SL versions of its popular e-MTBs, but the competition hasn’t backed down, either. Trek has been working hard to cement its place in the “halfway house” sector of electric mountain bikes; those which have electrical features, but don’t compensate on a natural ride feel or weight.
One of its responses to this new area of e-MTBing is the Fuel Exe 9.9 XX1 AXS. But does it reach the mark? And how does it compare to the other players in the market? In our Fuel EXe 9.9 XX1 AXS review, we’ve put the hours in on the trails to hopefully preempt as many of the potential questions you might have as possible.
Join us, then, as we delve into this Trek e-MTB…
Our Verdict
Has Trek achieved what it wanted to with this bike? Absolutely! The company has nailed it, creating a versatile, playful, lightweight e-MTB, which handles like a dream.
It bridges the gap nicely between the MTB and e-MTB world, and at times, you forget you’re actually riding an e-MTB at all.
The bike isn’t completely lacking in the assistance area, either; it has a decent motor, epic display and has a natural feel to its power delivery. However, the price is thoroughly upsetting – it’s extortionate and the tyres let it down.
Tweak the price and the tyres and you’ll have the full package and a bonafide market leader.
Peaks:
- Weight
- Handling
- Motor display
- Natural ride feel
Troughs:
- Price
- Tyres
- Motor power
- Battery range
Trek Fuel EXe 9.9 XX1 AXS
Price: $16,250
Weight/Frame
The Fuel EXe 9.9 XX1 AXS has a fully carbon OCLV frame, which adds to a total bike weight of 18.45kg (we reviewed the bike in the medium size). It’s a real achievement by Trek to keep that weight down, and all the cabling is routed internally, giving the bike a refined finish.
Perhaps you’re wondering what the geometry is like on this Fuel EXe? Well, it’s definitely worth highlighting how hard the company has worked to try and offer a tailored feel to the bike.
They’ve offered 8 different framing sizes from which to choose, including two different types of small, medium, large and extra-large frames – all of which have slightly different geometry. It’s a clever move to try and give the rider ultimate handling ability while out on the trail and make the most of that light, playful weight.
The finish on the EXe 9.9 XX1 AXS looks very similar to non-electrical assisted Trek e-MTBs.
On the trail, the bike handles impeccably downhill and is well-balanced. It’s also easy to manipulate through the twisty sections and it feels light-footed on the climbs, too. The modest weight for an e-MTB still takes it over many conventional MTBs, but that keeps you planted to the trail and you feel secure out there while moving at pace.
Battery
Trek went a bit “left field” with its choice of battery partner, looking to TQ, a company that’s more commonly known for its work in aviation and robotics. The battery the company went for was TQ’s 360Wh battery; it’s clearly not a monster of a battery, but it’s still not completely insignificant, either.
On our review rides, we managed to knock out around 35km on one charge, with over 1,200m of climbing.
ℹ️ It’s an important time to reflect on what you’re looking for from an e-MTB. If you want a bike which will assist you all day long without pause for thought, then you’ll be barking up the wrong tree by going for the Fuel EXe 9.9 XX1 AXS.
As we’ve tried to make clear from the start, this bike is in the “halfway house” genre, offering elements of assistance, but still having a similar feel to a conventional e-MTB. If it was paired with a bigger battery, you would find the weight spiking and you lose a lot of that playfulness..
Trek went a bit “left field” with its choice of battery partner, looking to TQ, a company that’s more commonly known for its work in aviation and robotics. The battery the company went for was TQ’s 360Wh battery; it’s clearly not a monster of a battery, but it’s still not completely insignificant, either.
On our review rides, we managed to knock out around 35km on one charge, with over 1,200m of climbing.
Motor
Trek looked to TQ again for its motor pairing for the Fuel EXe 9.9 XX1 AXS. The bike comes with TQ’s HPR50 motor, which kicks out 50Nm of torque. We’re impressed with that power delivery from a bike weighing under 19kg.
It’s quite a bit more powerful than some of the bikes in Specialized’s SL ranges, which only kick out 35Nm of torque, and you can feel that welcome difference out on the trails. It’s a beauty of a motor, which operates near-silently, adding to that impression that you’re riding a normal MTB.
You have 3 modes of power delivery to flick between – Eco, Mid and High – and it’s delivered in a very natural way. A stroke of the peddle immediately engages the electrical assistance (when it’s switched on), which is very handy when you’re looking for a boost on the climbs – there’s no hesitation and you find the motor’s output reliable as a result.
Another real achievement from the TQ motor is that you don’t have any lag when you stop peddling either – the assistance stops as you stop, which means you don’t have a slice of overrun, which can cause problems and create unpredictability out on the trails.
ℹ️ We’re very fond of this motor, but just like the battery, you have to be aware about what you’re going for here – it isn’t designed to be a full on powerhouse, it’s meant to be a middle ground between a full e-MTB and a normal MTB.
Motor Display
The motor display on the Fuel EXe 9.9 XX1 AXS is another fantastic piece of kit. It’s integrated into the top-tube of the frame and is pretty advanced compared to some displays, such as the Shimano EP8.
We’re delighted to see a percentage figure of battery left, which some motor manufacturers still fail to do. You also get many customisable features, including an estimated range figure, information on your power output, speed, the distance you’ve covered, RPM and many other slices of data.
It’s really quite an advanced display and it’s fair to say we’re big fans. You can also hook the bike up to the company’s Trek Central smartphone app and download all of your ride data.
Suspension
The Fuel EXe 9.9 XX1 AXS comes with 150mm travel at the front and 140mm travel at the rear. It’s fitted with RockShox Lyrik Ultimate, AirWiz, DebonAir spring forks and RockShox Super Deluxe Ultimate AirWiz shocks with RCT2 dampers.
It’s a well-balanced suspension setup, which works well with the bike’s geometry. It comfortably copes with fast-flowing trails packed with obstacles, as well as aggressive cornering. It’s also helped by the bike’s weight, which although in the playful bracket, still also offers a planted footing on the trail.
It could potentially falter on the biggest drops and gnarliest full-gas descents, but Trek has placed this bike admirably in the enduro section of the market and it does the job well. At times, you genuinely forget you’re riding an e-MTB; it handles beautifully and has the light-footedness of a normal MTB.
Wheels/Tyres
The Fuel EXe 9.9 XX1 AXS is fitted with 29in Bontrager Line Pro 30, OCLV Mountain Carbon wheels at both the front and the rear. We’ve talked about the bike’s planted feeling on the trail and the larger wheels help achieve this, whilst also giving you plenty of clearance to get up and over obstacles.
This Trek e-MTB comes with Bootranger SE5 Team Issue tyres. Now, we have a problem with these. We ended up getting a few punctures on our review rides and found ourselves slipping out when really giving the bike a good thrash around, particularly into sharp corners.
The bike is absolutely bang-on in other areas and many of its other features lend itself to be ridden aggressively, but the tyres don’t match that. They need more bite and traction into the dirt. They’re one of the few let downs in this Trek e-MTB review.
With this poor tyre performance in mind, why not check out our guide on the 10 Best Electric and Standard Mountain Bike Tyres for Road and Trail?
Brakes
The Fuel EXe 9.9 XX1 AXS comes with SRAM Code RSC hydraulic disc brakes. These are a decent pairing to the power output that the motor kicks out. They never feel overfaced or incapable of bringing the bike to halt.
Drivetrain
The Fuel EXe 9.9 XX1 AXS comes with a 12-speed SRAM Eagle XG-1299 cassette and SRAM XX1 Eagle AXS rear derailleur. They do the job nicely.
Price: $16,250
Ok, the price is absolutely eye-watering, there’s no getting away from that. We know that it’s an absolutely enormous investment, but you’re getting a seriously good bike for that price – it’s an absolute belter to ride.
It’s let us down in the tyres department and Trek could definitely improve that area, however, it’s only a slight failure in what is otherwise a bang-on bike.
It’s also more expensive than some of its competitors in this “halfway house” area, which we’ll come to more in our comparison section.
Fuel EXe 9.9 XX1 AXS Facts & Figures
Size Configurations
| SIZE | RIDER HEIGHT | INSEAM |
|---|---|---|
| S | 155 – 165 cm 5'1″ – 5'5″ | 74 – 78 cm 29″ – 31″ |
| M | 165 – 176 cm 5'5″ – 5'9″ | 79 – 83 cm 31″ – 33″ |
| L | 177 – 188 cm 5'10” – 6'2″ | 84 – 89 cm 33″ – 35″ |
| XL | 188 – 195 cm 6'2″ – 6'5″ | 89 – 91 cm 35″ – 36″ |
| SIZING TABLE | ||||||||
|---|---|---|---|---|---|---|---|---|
| Frame size number | 15.5″ | 15.5″ | 17.5″ | 17.5″ | 19.5″ | 19.5″ | 21.5″ | 21.5″ |
| Frame size letter | S | S | M | M | L | L | XL | XL |
| Geometry position | High | Low | High | Low | High | Low | High | Low |
| Wheel size | 29″ | 29″ | 29″ | 29″ | 29″ | 29″ | 29″ | 29″ |
| Seat tube | 38 | 38 | 41 | 41 | 43.5 | 43.5 | 47 | 47 |
| Seat tube angle | 69.3° | 68.8° | 69.8° | 69.3° | 70.8° | 70.3° | 71.3° | 70.8° |
| Effective seat tube angle | 77.3° | 76.8° | 77.3° | 76.8° | 77.3° | 76.8° | 77.3° | 76.8° |
| Head tube length | 10 | 10 | 11 | 11 | 11 | 11 | 12 | 12 |
| Head angle | 65.3° | 64.8° | 65.3° | 64.8° | 65.3° | 64.8° | 65.3° | 64.8° |
| Effective top tube | 57.2 | 57.3 | 59.9 | 60 | 62.9 | 63 | 65.6 | 65.8 |
| Bottom bracket height | 34.1 | 33.4 | 34.1 | 33.4 | 34.1 | 33.4 | 34.1 | 33.4 |
| Bottom bracket drop | 3.2 | 3.9 | 3.2 | 3.9 | 3.2 | 3.9 | 3.2 | 3.9 |
| Chainstay length | 43.8 | 44 | 43.8 | 44 | 43.8 | 44 | 43.8 | 44 |
| Offset | 4.4 | 4.4 | 4.4 | 4.4 | 4.4 | 4.4 | 4.4 | 4.4 |
| Trail | 12.4 | 12.7 | 12.4 | 12.7 | 12.4 | 12.7 | 12.4 | 12.7 |
| Wheelbase | 118.7 | 118.8 | 121.6 | 121.7 | 124.6 | 124.7 | 127.6 | 127.6 |
| Standover | 73.2 | 72.6 | 73.3 | 72.7 | 73.9 | 73.3 | 75.9 | 75.3 |
| Frame reach | 43.4 | 42.8 | 45.9 | 45.3 | 48.9 | 48.3 | 51.4 | 50.8 |
| Frame stack | 61.6 | 62 | 62.5 | 62.9 | 62.5 | 62.9 | 63.4 | 63.8 |
*All measurements provided in cm unless otherwise stated.
Full Specs
| FRAMESET | |
|---|---|
| Frame | OCLV Mountain Carbon, removable battery, internal routing, alloy rocker link, 34.9 mm seat tube, upper chain guide mount, 55 mm chainline, Mino Link, ABP, Boost148, UDH, 140 mm travel |
| Fork | RockShox Lyrik Ultimate, AirWiz, DebonAir spring, Charger 3 RC2 damper, 44 mm offset, Boost110, Maxle Stealth, 150 mm travel |
| Shock | RockShox Super Deluxe Ultimate AirWiz, RCT2 damper, 205 mm x 60 mm |
| WHEELS | |
| Wheel front | Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless-Ready, 6-bolt, Boost110, 15 mm thru-axle |
| Wheel rear | Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, Rapid Drive 108, 6-bolt, SRAM XD driver, Boost148, 12 mm thru-axle |
| Skewer rear | Bontrager Switch thru-axle, removable lever |
| Tyre | Bontrager SE5 Team Issue, Tubeless Ready, Core Strength sidewalls, aramid bead, 120 tpi, 29×2.50 |
| *Tyre part | Size: S, M, L, XL Bontrager TLR sealant, 180 ml/6 oz |
| Size: S, M, L, XL Quarq TyreWiz tyre pressure monitors | |
| DRIVETRAIN | |
| Shifter | SRAM Eagle AXS, wireless, 12 speed |
| Rear derailleur | SRAM XX1 Eagle AXS |
| Crank arm | E*thirteen E*spec Race carbon, 34T, 165 mm length |
| Chainring | SRAM X-SYNC, 32T, alloy |
| Cassette | SRAM Eagle XG-1299, 10-52, 12-speed |
| Chain | SRAM XX1 Eagle, 12-speed |
| Max. chainring size | Max: 34T Min: 30T |
| COMPONENTS | |
| Saddle | Bontrager Arvada, austenite rails, 138 mm widt |
| *Seatpost | Size: S RockShox Reverb AXS, 100 mm travel, wireless, 34.9 mm, 340 mm length |
| Size: M RockShox Reverb AXS, 150 mm travel, wireless, 34.9 mm, 440 mm length | |
| Size: L, XL RockShox Reverb AXS, 170 mm travel, wireless, 34.9 mm, 480 mm length | |
| *Handlebar/stem (integrated) | Size: S Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 35 mm stem length |
| Size: M, L, XL Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 45mm stem length | |
| Grips | Bontrager XR Trail Elite, nylon lock-on |
| Brake rotor | SRAM 6-bolt, 200 mm |
| Brake set | SRAM Code RSC 4-piston hydraulic disc |
| ACCESSORIES | |
| *Battery | Size: S, M, L, XL TQ 360Wh |
| Size: S, M, L, XL SRAM eTap battery pack (with charger) | |
| Motor | TQ-HPR50, 50 Nm, 250 watt maximum continuous rated power, 300 watt peak power |
| Computer | TQ LED display with Bluetooth & ANT+ connectivity |
| *Electronics | Size: S, M, L, XL TQ 4A charger |
| Size: S, M, L, XL SRAM AXS aux power cable | |
| Tool | Bontrager BITS integrated multi-tool |
| WEIGHT | |
| Weight | M – 18.45 kg / 40.68 lbs (with TLR sealant, no tubes) |
| Weight limit | This bike has a maximum total weight limit (combined weight of bicycle, rider and cargo) of 136 kg (300 lb). |
*All measurements provided in cm unless otherwise stated.
How Does it Compare?
The price of the Fuel EXe 9.9 XX1 AXS is a painful one on the wallet. Trek is far from being the only operator in the “halfway house” e-MTB market, there are other manufacturers who have brought out bikes which bridge the gap between MTBs and e-MTBs.
One of the other best companies in the business at these new wave e-MTBs is Specialized. Its Kenevo and Levo SL rides, targeting the downhill and enduro worlds respectively, are serious contenders. Since the Fuel EXe 9.9 XX1 AXS is more of an all-rounder than a downhill beast, we’ll look at the S-Works Turbo Levo SL.
This is the highest-spec bike in the Turbo Levo range. It comes with a slightly smaller 320Wh battery and a less powerful motor by 15Nm. You get 150mm of travel at the front and rear, offering just a slice more at the rear end than the Trek and a similar 29in wheel setup.
The S-Works comes in at 17.5kg, so slightly lighter than the Trek, however, you get more punch in the motor and battery department with the Trek. The price is a big head turner. At the time of writing, the Specialized is currently heavily discounted on the company’s website, now down to $10,800 from $14,500.
Although we love the Trek, that price saving on the S-Works is too hard to look away from – more than $5,000 cheaper. With that in mind, the Specialized takes it in this highly-sought-after category.
points
Trek Fuel EXe 9.9 XX1 AXS
points
Specialized S-Works Turbo Levo SL
30 facts in comparison
Trek Fuel EXe 9.9 XX1 AXS VS Specialized S-Works Turbo Levo SL
Is the Trek Fuel EXe 9.9 XX1 AXS better than the Specialized S-Works Turbo Levo SL?
- Downhill (DH) full-suspension Frame Material
Downhill (DH) full-suspension vsCarbon fiber - 18.45KG Frame Weight
18.45KG vs17.4KG - 360Wh Battery Size
360Whvs320Wh - 25km/h Top Speed
25km/hvs45km/h - 130KM longer maximum distance per charge
130KMvs130KM
Motor
MotorMAXIMUM TORQUE
50 NmMOTOR POWER
250 WTOP SPEED
25 km/h Versatility
VersatilityGEARS RATIO
Suspension Travel (in mm)
FRAME MATERIAL
Downhill (DH) full-suspensionTires
| Front Diameter | Back Diameter | Front Width | Back Width |
|---|---|---|---|
| 29 | 29 | 2.5 | 2.5 |
| Front Diameter | Back Diameter | Front Width | Back Width |
|---|---|---|---|
| 29 | 27.5 | 2.5 | 2.6 |
Handling
HandlingWEIGHT
18.45 KGSTABILITY IN ANGLE DEGREE
65.3
65.5
Battery
BatteryBATTERY SIZE
360 WhBATTERY WEIGHT
1.8 KGCHARGE TIME
2 hFinal Thoughts
This Trek Fuel is an absolutely beautiful bike, undoubtedly one of the best in the market.
The company came out wanting to smash the growing new market in the “halfway house” sector – lightweight and providing a natural ride feel, while also having e-MTB components. Has it achieved that? Quite frankly, yes!
Trek has created a wonderfully fun bike to ride, which handles like a dream, yet still has a slice of power to get you up the mountains when you’re struggling. It isn’t a bike for those who need a lot of assistance, it’s for riders who want to bridge the gap between a MTB and an e-MTB, and Trek has nailed it.
There are a few tweaks needed, particularly when it comes to the tyres, but overall, the Fuel EXe 9.9 XX1 AXS is a success in terms of how it rides. However, it isn’t cheap and that’s a turn off for us, but what do you think?
Hop aboard one and let us know your thoughts!
“If you enjoyed this review then make sure to check out our other Trek reviews.”
