So, you’ve decided it’s time to treat yourself to a new trail bike. Perhaps you’re upgrading from your trusty hardtail, or retiring your old enduro rig for something that excels on a wider range of trails?
Whatever the reason, you’re in for a treat: trail bikes are the most versatile mountain bikes – the jack of all trades, if you like – delivering grin-inducing riding wherever you take them.
The trail-bike experience was shaken up in 2022 with the release of Trek’s Fuel EXe. Dubbed the ‘incognito eMTB’, it made waves with its almost-invisible drive unit and battery, and unobtrusive ride feel.
Not long after the launch of the EXe, Trek released the sixth-generation Fuel EX. With an almost indistinguishable silhouette, the EX is the EXe’s non-motorised stablemate, sharing much of its design, and many of its features and innovations.
Both bikes should be high on your list of considerations, but how do you begin to choose between the two? Well, that depends on you as a rider and what you want from your trail bike. Let’s dive in and find out which of Trek’s trail offerings is for you.
- Read more: Why the only bike you need is a trail bike
What type of riding are you doing?
If we could only choose one mountain bike to ride, it would be a trail bike. While you may be slightly more comfortable riding the gnarliest descents on enduro and downhill bikes, there are very few trails that can’t be tamed with a modern trail bike.
Sure, you’ll have to be more precise with your line choice and riding approach, but the best trail bikes are incredibly capable descenders.
But what makes a great trail bike? Designed to be fun and engaging to ride on mellower trails, while also holding their own in the rough, trail bikes bridge the gap between the lively and responsive handling of lighter, shorter-travel bikes (such as cross-country bikes) and the confident, gnar-taming prowess of long-travel enduro bikes.
If your rides take you on a wide variety of trails, from undulating singletrack to trail-centre, off-piste enduro trails and the odd uplift day, chances are high that you’ll have the most fun on a capable trail bike.
Trek’s Fuel EX and EXe define this progressive trail bike category, combining capable geometry and suspension with a low overall weight and responsive handling. They share many of the same features, which we’ll explore later, and their main difference lies largely out of sight.
The Fuel EXe’s hidden power is its TQ HPR50 motor. Using a unique harmonic pin ring transmission, which makes it smaller, lighter and quieter than conventional eMTB drive units, the TQ motor delivers 50Nm of torque to help you pack more trails into your ride.
TQ explains the harmonic pin ring system as two gears that sit on a central axis and are connected by a transmitter called a pin ring. According to TQ, not only is the HPR system efficient and maintenance-free, but it can also be made to be very compact.
Paired with a 360Wh internal battery, the HPR50 motor gives you a claimed two to five hours of assisted riding. If that doesn’t sound long enough, Trek has you covered with an optional 160Wh extender, bumping the Fuel EXe’s range up to between three and seven and a half hours.
Geometry
A bike’s geometry largely determines how it will feel on the trail – it’s a crucial piece of the puzzle, effectively creating the foundations of its character.
Modern trail bikes have adopted geometry that, until recently, would have been reserved for enduro bikes, bringing slack head angles, roomy reach figures and steep seat tubes to a lighter, shorter-travel package.
The Fuel EXe, which comes in sizes small, medium, large and extra-large, with reach figures ranging from 427mm to 507mm, ticks those boxes perfectly.
As you’d expect from Trek, there’s a Mino Link (a flip chip located at the seatstay/rocker pivot), which can be flipped to sit the bike in either the low or high setting.
This alters the head and seat angles by 0.4 to 0.5 degrees (depending on size) and the bottom bracket height by around 7mm.
In the low setting, the Fuel EXe’s head angle is a slack 64.7 degrees, while the seat angle should help to sit you comfortably for climbing at 76.7 degrees. The chainstay measurements across all frame sizes remain the same at 440mm in low.
While all sizes of the Fuel EXe come with 29-inch wheels at the front and rear as standard, you can switch to a 27.5-inch rear wheel if you wish by setting the Mino Link to its high setting.
The latest generation of the Fuel EX features similarly progressive geometry. It also has a Mino Link, as well as a geo-adjust headset, which gives three options – Slack, Neutral and Steep.
This offers a head-angle adjustment from 63.5 degrees (in Slack and MinoLink in Low) and 64.5 degrees (Neutral) up to 65.5 degrees in Steep. As is common with adjustable headset cups, there's minimal impact on other areas of the bike's geometry.
All Fuel EX models ship with the Neutral headset, with a rotatable headset cup available aftermarket, offering the Slack and Steep options. If you’re yearning for more geometry adjustment on the Fuel EXe, the aluminium models have you covered – they’re compatible with the same rotatable headset cup as the Fuel EX.
Suspension
The Fuel EX and EXe share very similar silhouettes, thanks in part to their similar suspension design, which gives both bikes 140mm of rear-wheel travel.
Trek’s Active Braking Pivot (ABP) has a concentric pivot around the rear axle, where the chainstays meet the seatstays.
Trek says this enables it to isolate brake force and suspension function, meaning your suspension should perform just as well under heavy braking as it does off the brakes.
The compact size of the TQ HPR motor has given Trek the freedom to design the Fuel EXe’s suspension layout without compromising for a bigger, bulkier motor. For example, the main pivot has been shifted forward slightly compared to that of the previous Fuel EX, in a bid to create more consistent anti-squat figures and improve pedalling performance.
While it lacks the progression-adjustability of the Fuel EX (controlled via the Mino Link), the electric Fuel still boasts a solid leverage curve, with around 20 per cent progression. That means using a coil shock should be possible, but heavier riders will likely need to have some kind of bottom-out control for it to work as well as an air shock.
Sizing
Finding the right size frame for your height is crucial, and, if possible, we always recommend trying a bike before you buy.
Both the Fuel EX and Fuel EXe are available in a broad range of sizes. However, there are some differences to note.
The non-motorised Fuel EX is available in six different sizes, with multiple wheel-size configurations. The smallest XS size rolls on 27.5in wheels, while size S gets the option of full 27.5in or a mixed ‘mullet’ setup with a larger 29in wheel at the front. Sizes M, ML, L and XL all roll on 29in wheels from the factory, but are mullet-compatible.
The Fuel EXe comes in four sizes (S, M, L and XL), which are all specced with full 29in wheels as standard.
Specs
Trek offers both its trail bikes in a wide range of builds, appealing to different price points. The first choice you will have to make is whether to go for a carbon or aluminium frame. There are benefits to both: carbon is lighter and offers a more direct, stiffer ride feel, which some riders love. Others, however, will prefer the ruggedness of aluminium and the slightly more forgiving feeling it offers on fast, rough trails.
If you are looking for the ultimate value for money, it’s hard to ignore the alloy Fuel EX offerings.
Prices start at £1,750 for the Fuel EX 5, which has entry-level kit from the likes of RockShox, X-fusion and Shimano. A spec highlight of the Fuel EX 5 is the 12-speed Shimano Deore drivetrain.
Next up is the Fuel EX 8, which is available in three models with prices ranging from £2,600 to £4,500.
All three models share the same Fox suspension, and Bontrager wheels and tyres. They differ in their brake and drivetrain components, with the EX 8 running a mix of Shimano XT and SLX drivetrain parts and SRAM’s DB8 brakes. The mid-range EX 8 XT build gets a Shimano XT drivetrain and Deore M6100 brakes, while the top-of-the-range alloy Fuel EX 8 GX AXS has SRAM’s latest GX Eagle AXS T-Type drivetrain and DB8 brakes.
Pricing for the Fuel EXe starts at £4,500 for the alloy EXe 5 model, which shares many of the same components as the EX 5. Of course, it also has the same TQ motor and battery as the rest of the electric Fuel line-up. Topping the aluminium Fuel Exe range is the GX AXS T-Type model, which costs £6,125 at RRP. It shares the same specifications as its non-motorised stablemate.
Towards the top of the range sit the EX and EXe 9.8 models. These bikes get Trek’s OCLV carbon frame, RockShox or Fox suspension, and high-end brakes and drivetrains from Shimano or SRAM.
This spec-matching between the EX and EXe models means you can simply choose between the electric or analogue Fuel, without having to compromise on the components you want.
Trek Fuel EX vs Fuel EXe, which should you choose?
It’s safe to say that both the Trek Fuel EX and the Fuel EXe are amazing trail bikes. The pivotal factor to base your choice around is not so much their geometry, spec or even descending performance, but whether or not you want the subtle boost of the TQ motor.
If you’ve never fancied owning an eMTB and are happy pedalling all day, you will find a great trail companion in the Fuel EX. However, if you dream of squeezing a couple of extra laps in during your post-work rides, or fancy a little helping hand on longer pedals without the noise and bulk of a full-power ebike, then the sleek and light Fuel EXe might be just the ticket for you.
It won’t rock your ride with endless torque, power or battery capacity, but that’s not what it was designed for. Instead, you’ll barely notice its motor as you breeze up the climbs, before dropping in for another grin-inducing descent.
