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Field Test Review: 2022 Trek Top Fuel - Same Name, Different Bike

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Trek Top Fuel 8 review

• Alan Muldoon
• July 27, 2023

Once a lean XC race-focused machine, now a bulked up down-country rig. We test Trek's latest take on its short travel full suspension design.

Trek Top Fuel 8 Credit: Roo Fowler

Product Overview

Overall rating:, trek top fuel 8.

• • Poppy, playful and efficient
• • Available in six frame sizes
• • Internal down tube storage
• • Mino Link flip chip allows geometry tweaks
• • Needs a 180mm rear rotor
• • Accurate rear shock set up is crucial
• • A solid build, so not the lightest in its class

Manufacturer:

Price as reviewed:.

Think Top Fuel, and the image of a XC race bike instantly springs to mind. But like a faded polaroid tucked into the corner for a dusty picture frame, it’s not an accurate representation of the current design. With the Fuel EX increasing in travel, the Top Fuel has been swept along in its backdraft and seen in high definition, it’s now a capable 29er trail bike with modern sizing and 120mm travel and one of the best down-country bikes on sale. 

A dropper post and sorted cockpit complement the Top Fuel’s playful and poppy nature

Trek offers the new Top Fuel in carbon and alloy options, where the Top Fuel 8 tested here is the high-end alloy build. Regardless of frame material all Top Fuels come with integrated downtube storage. And while the quick release hatch under the bottle cage isn’t big enough to cram a three course lunch into the frame, there’s enough space for a tube, multi-tool, a few snacks and a lightweight jacket. 

Down tube storage is handy for those riders who are travelling light

Trek always offers a comprehensive size range; and with frame options from S to XXL, with a tweener M/L option too, the Top Fuel 8 is no exception. It also has geometry adjustment, but rather than having Trek’s signature Mino Link on the seat stay pivot, the Top Fuel has a flip chip at the lower shock mount. In the low setting this gives a relatively tall 340mm BB height for a 120mm bike, which is probably the only carryover from its race-bike roots – designed to let you keep the cranks spinning, and the speed high at all times.

• Best down-country mountain-bike: short travel full-suspension

The rest of the Top Fuel’s vital stats are on the money though, where a slack 65.6º head angle and steep 77.2º effective seat tube angle make it easy to hammer up the climbs and shred the descents. 

Flip chip in the lower shock mount offers 0.5deg head angle and 8mm BB height adjustment

It’s built solid too, the complete bike tipping the scales at 14.89kg. It also comes with a combined rider and bike weight limit of 136kg (300lb) so it’s clearly no wet noodle. Yes, it’s not the lightest for a 120mm bike, and not far off what you’d expect for a 150mm bike, but that’s the price you pay for integrated storage, as the alloy down tube needs reinforcing when you cut a hole in it.

Thankfully, the Top Fuel 8 rides light, as there’s less travel to pull through to get the bike off the ground, so it offers a different ride experience to modern long-travel trail bikes which tend to have one eye on enduro racing. 

The stock RockShox Pike Rush RC fork dishes out 130mm of travel

There are no sag gradients on the 130mm travel RockShox Pike fork, which we assume is down to cost saving, but set-up is still really straightforward with a tape measure to hand. And while the Pike has a reputation for having a sporty, firmer tune, the basic RC version on the Trek felt smooth and composed in all situations. Yes, the RC damper has a very wide range of rebound adjustment, but there’s only a small range that’s actually usable, but it is enough to get the rebound just so; and that’s all that really matters, right?

• Best mountain bike suspension forks: XC, trail and enduro forks

You need to be equally attentive when setting up the rear suspension. Set to 30% sag, the top-end RockShox Deluxe Ultimate RCT shock bottoms relatively easily. So if you want to run the shock softer to achieve a lower dynamic BB height, you’re going to need to add volume spacers. As such, we increased the shock pressure and reduced the sag to 27.5%.

This small change alone was enough to prevent premature bottom out, but we could still use all of the available shock stroke when we really needed it. We also ran the low-speed compression setting in the minus position for maximum plushness. In the low geometry setting we measured rear wheel travel at 115mm, which is 5mm less than claimed. 

One of the biggest differences in terms of ride feel between the Lapierre and the Trek, other than sizing, are the wheels. The Bontrager Line 30 rims have a 30mm internal rim width, 5mm more than the Mavic rims on the Lapierre XRM 6.9 we tested the Trek against. This adds to the overall volume of the tyres and the stiffness of the bike. It is also why we dropped the tyre pressures slightly on the Trek, even though we were running the exact same tyres on both bikes. 

Bolted on chainstay protection is a neat and considered touch

With 108 points of engagement the freehub on the Bontrager rear wheel offers rapid, secure engagement, with less chain slack and chain slap as a result. The bike is not totally silent though as there is a little bit of cable rattle, but it will probably disappear when you stuff the BITS storage box to the gills.

The contact points on the Top Fuel 8 are all sorted and while there’s a stack of stem height adjustment, the three 20mm spacers don’t offer any fine tuning of the handlebar height. So swapping one of the 20mm spacers of a 10mm, a 5mm and two 2.5mm spacers, would be our first move before leaving the store.

• How to: ultimate guide to handlebar cockpit set up

Nothing else needs changing though. The mix of Shimano XT and SLX for the 12-speed drivetrain worked flawlessly in the dry, dusty test conditions, where the smaller 30t chainring is a real saviour on long draggy climbs or on days when your legs feel like lead. 

ABP suspension design transforms the seat stay assembly into a floating brake mount

Performance

The steep seat tube angle on the Trek Top Fuel 8 really helps with the pedalling dynamics on steeper climbs and the cockpit is long enough that even with the shorter 45mm stem, you never feel cramped or uncomfortable when climbing. It’s not so steep though, that it feels like the pedals are behind you when sitting down spinning across flatter, rolling singletrack.

Stand up to sprint and the rear suspension on the Trek clearly gets animated, the rocker link flapping around like the tail on an overly excited puppy. So the best approach is to sit and spin up the climbs, as the shock remains remarkably still and lifeless until you encounter a bump. Also if you really want to go for it on smoother climbs, the rear shock has a firmer pedal threshold setting. In short then, gaining elevation on the Top Fuel 8 is relatively straightforward and painless.

Knock Block 2.0 steering lock with 72º steering angle, protects the frame without limiting steering

So, it’s somewhat surprising just how rapidly you can throw those gains away. This bike simply rips the descents. Given the limited travel it still seems to carry speed everywhere, and while bumps that would normally chip away at your momentum are still felt though the chassis, they do not perturb the Trek one bit. It rails corners too. Simply load up the suspension mid-turn, and the Top Fuel has just the right amount of support and extension to keep the front end loaded, before slingshotting you out of the turn faster than you entered it. Combine the raw speed with the balanced weight distribution, and the Top Fuel 8 is a really fun, exciting ride and blisteringly fast too.

Would the Trek Top Fuel 8 be even faster with a genuinely low geometry setting? You bet it would. But we’d settle for a bigger rotor on the SRAM DB8 rear brake, as this bike is so fast in fact, that the 160mm rotor feels wholly inadequate and it looked like it had been tempered after just a couple of rides. 

• Best cross-country XC mountain bikes: hardtail and full suspension

The Top Fuel 8 is at home on fast sweeping singletrack

At 14.89kg (32.83lb), the Trek Top Fuel 8 isn’t that much lighter than a 150mm bike. So if you want one bike to conquer all trails, it wouldn’t be our first choice. It’s still a great 29er trail bike though, and if bike park laps and enduro racing don’t fall under your trail bike remit, the Trek Top Fuel 8 offers a fast, fun and engaging ride. Its poppy playful nature, combined with generous sizing means you never feel limited by the travel for regular trail riding. Yet, it still feels more energetic and efficient under pedalling than than most 150mm bikes. It’s a heady combination that manages to keep both the tempo and fun factor high, without any apparent lows.

Trek Top Fuel 8 review: a progressive rather than podiuming XC machine

Trek’s top fuel delivers superlative short-travel suspension performance but it’s definitely a trail bike not an xc bike.

BikePerfect Verdict

Awesome suspension, agile swagger, grippy kit and practical frame updates build a brilliant rally bike, but high weight buries any XC aspirations

Infectiously agile and playful vibe

Superlative suspension feel

Seriously tight tracking frame

Trail tough kit

Internal storage

Too heavy for XC racing

Simple fork damper

Tight internal storage access

Yawning gap between this and the Supercaliber

Why trust BikePerfect Our cycling experts have decades of testing experience. We'll always share our unbiased opinions on bikes and gear. Find out more about how we test.

Top Fuel used to be Trek’s out-and-out best full-suspension mountain bike for racing, but with the soft-tail Supercaliber under its sponsored riders now, the Top Fuel has developed a burly rather than race character. 

The latest frame, suspension and spec changes to the 8 make the most of its short-travel agility and gripped tenacity to create a proper rally racer. Excess weight shows on climbs and acceleration though.

Design and geometry

The alloy Top Fuel frame not only has the same geometry, shock and suspension layout as its carbon counterpart but Trek’s engineers have also worked super-hard to give it the same extensive, updated feature lineup. That includes the lever-locked trapdoor into the down tube for internal storage, threaded bottom bracket shell with chain guide tabs. The Knock Block 2.0 inset now allows 72-degrees of steering lock (not 58-degrees as before) or you can fit a blank insert for full rotation if the bars aren’t slammed. 

In fact, it’s one of those bikes where we continually found ourselves riding how we always want to ride, not how we actually ride. That inevitably builds into an addictive upward spiral of confidence and insolent speed that often ended with us snapping at the heels of more expensive longer travel bikes even on really rowdy trails. Picking a larger, longer frame will settle it even more at speed, but for flow trails, it was refreshing to really rip those big Bontrager side tire lugs round on a compact, close combat chassis. Just be careful you don’t get too carried away, as however good it feels, less travel inevitably means the tires are having to cope with more impact force and we soon put a couple of splits in the rear tire despite the ‘inner strength’ casing.

When that happens the narrow neck of the storage hatch can make getting your spare tube out awkward and the high cage position means you won’t get a large bottle in either. There’s space for a 2.5in tire in the rear swingarm which pivots co-axially around the rear axle according to Trek’s ‘Active Braking Pivot’ wisdom. While it limits choice, the switch to a 34.9mm seatpost size should mean stiffer, smoother dropper action, especially on larger frame sizes which get up to a 200mm shaft stock. The new trunnion style shock pivots more smoothly and is the right way up now compared to last year’s inverted shocks. That means the MinoLink geometry flip chip to change angles by 0.5-degrees is now at the base of the shock but it’s still easy to get too. Significantly all RockShox spec Trek bikes from the 8 upwards get the same ‘Ultimate RCT’ spec Deluxe rear shock.

The alloy frame is a kilo heavier (3.74kg vs 2.7kg) than the carbon option according to Trek’s weights. This saves you $1,400/£1,500 if you buy the frame separately, although it still retails for $2,319.99/£2,350. Those numbers prove it’s neither affordable or light for a bike that you’ll find listed in the XC section of Trek's website, not the trail pages. In fact, the 130mm Fuel EX Al frame is the same weight although that doesn't have internal storage.

A 66/66.4-degree head tube definitely suggests progressive riding rather than traditional podium hunting vibes too. The 465/469mm reach on our M/L size is more trad than rad though so riders after a stretch should make use of the short 450mm seat tube and opt for the L with a 480/484 reach. All bikes get the same 76/76.4-degree seat tube angle and 434/435mm chainstay length though so while having six (S-XXL) sizes is great, the balance is definitely centered around the M - M/L - L models.

Components and build 

The Top Fuel 8 is the most expensive alloy bike, above the 7 at $3,529.99/£3,200 and the 5 at $2,629.99/£2,700 (we don’t know what 6 did to offend them but its missing from the line-up), but below the carbon-framed 9.7 at $4,229.99/£4,700.

The highlights of the package are the lightweight SID fork (albeit with the simplest Rush Damper) and Shimano XT rear mech and shifters. The Bontrager XR4 tires are some of our favorite welterweight all-rounders too. The SLX crank is a great piece with a 30T ring for easy climbing, but muscle Mary’s will find a 36T fits the frame too. You get a 150mm Trans-X dropper with a Bontrager Arvada saddle on top and 35mm diameter Bontrager Elite 45mm stem and 780mm wide bar.

Deore four-pot brakes just about do the job adequately via 180/160mm rotors but together with the wide rim tubeless Bontrager Line Comp 30 wheels they’re an obvious area where extra weight creeps in and adds up to nearly 14.5kg without pedals. 

Performance

Add that weight to chunky treaded, relatively grippy tires and however Trek categorizes the Top Fuel, the 8 clearly isn’t the best choice for charging climbs and ripping round simple XC laps. Now we’ve got rid of the people who’ll likely love the 12.2kg Trek Supercaliber for the same money, we can start talking about what the Top Fuel does do really well – and that’s riding properly rowdy.

While bikes like the Evil Following , Santa Cruz Tallboy , and Norco Optic have already established that short-travel bikes can feel awesome, the Top Fuel definitely goes into the small travel, BIG capability hall of fame. Like most of its peers, it doesn’t squander initial shock movement and can feel slightly sharp in the car park unless you drop tire pressures low. 

Once moving though it’s both amazingly fluid and connected over ruts and roots whether climbing janky tech or sucking onto stutter bump/root ripple turns or off-camber high lines. The wheel path and rear pivot position mean there’s minimal pull back through the pedals as it hoovers up chunder so you can stay on the gas without getting jacked or stalled out. While we’re always suspicious of acronyms and a 160mm rotor doesn’t generate much torque anyway, the braking performance of the ABP rear end is impressively grippy compared to the same hardware on other bikes. 

The RCT damper also has plus and minus low-speed compression settings to fine-tune support sensitivity depending on personal/terrain preferences. Even in the plus setting the mid-stroke mobility does mean you’ll want to flick into the much firmer ‘pedal’ mode if you’re stood up slow cadence churning on a climb or don’t want distracting bounce on long smooth climbs. The SID fork gets a similar firming option via the fork top lever though we rarely touched it unless we were really hanging on a road climb.

While the superlative suspension performance is definitely the heart of the Top Fuel’s ‘have a go hero’ character, the rest of the bike definitely exploits it rather than squandering it. The alloy frame might be heavy but it’s seriously stout when it comes to squaring up to the trail when things get punchy.

While the simpler Rush damper starts to get seasick and inconsistent well before the back end, the 35mm stanchions do a great job of staying on track. Shorter travel means less dive too and together with well-balanced cockpit dimensions and steering angle gives a really predictable and tenacious target lock.

Despite the hefty weight and relatively slow rear hub engagement the fact you can keep the power down or brake really late meant the Top Fuel always felt hyped to be hitting trails and tweaking lines as fast as possible. The shorter M/L size made it a proper joyride on tighter, twistier trails but you can still drive it really hard, heels down, feet level through turns and it loves to pump downslopes.

Trek’s Top Fuel 8 is a brilliant example of just how good short-travel suspension can feel, and less stroke always means a more responsive, visceral ride than a leggier bike. The geometry and proper trail tires really let you exploit the hooligan that’s hiding in the frame along with your pump, tool and spare tube too. 

As much as we’ve loved ripping around the trails on it, there’s no doubt it’s heavier and harder to accelerate/elevate than we’d like for its supposed XC/downcountry range placement though. If you’re about the overall vibe, not outright velocity, that doesn’t matter though.

Test conditions

• Temperature: -2 to 8 degrees
• Surface: Mixed blue-black trail center, moorland tracks, off-piste wooded tech and DH

Tech Specs: Trek Top Fuel 8

• Price: $3,829.99 / £3,850
• Model: Trek Top Fuel 8
• Discipline: XC/downcountry/trail
• Head angle:  66/66.4-degrees
• Frame material: Alpha Platinum Aluminium
• Weight: 14.46kg
• Wheel size: 29 x 2.4in 
• Suspension: RockShox SID 120mm travel, 44mm offset/RockShox Deluxe Ultimate RCT 120mm travel
• Drivetrain:  Shimano XT M8100 mech and shifter. Shimano SLX M7100, 10-51 cassette, chain
• Cranks:  Shimano XT 30T chainset
• Brakes:  Shimano Deore M6000 brakes with 180/160mm rotors
• Cockpit:  Bontrager Line 780mm bar and 45mm stem
• Wheelset:  Bontrager Line Comp 30 wheels
• Tires:  Bontrager XR4 Team Issue 29 x 2.4in tires
• Seatpost:  TranzX 150mm dropper post
• Saddle: Bontrager Arvada, steel rail saddle

Guy has been working on Bike Perfect since we launched in 2019. Hatched in Yorkshire he's been hardened by riding round it in all weathers since he was a kid. He spent a few years working in bike shops and warehouses before starting writing and testing for bike mags in 1996. Since then he’s written several million words about several thousand test bikes and a ridiculous amount of riding gear. To make sure he rarely sleeps and to fund his custom tandem habit, he’s also penned a handful of bike-related books and talks to a GoPro for YouTube, too.

Current rides: Cervelo ZFS-5, Forbidden Druid V2, Specialized Chisel, custom Nicolai enduro tandem, Landescape/Swallow custom gravel tandem

Height: 180cm

Weight: 69kg

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Tested: Trek Top Fuel

Don't call it a race bike. Trek's new Top Fuel is for railing steep fast decents with no course tape in sight.

Takeaway: Trek’s latest edition of the Top Fuel moves from being a big cross country racer and becomes a short travel trail bike. With new longer and slacker geometry, plus 5mm of extra travel, it aims to give riders the efficiency they want for long days while still enabling them to ride more technical trails with confidence.

• Fully guided internal routing in the front triangle plus a 73mm BSA threaded bottom bracket simplifies maintenance for both professional and home mechanics.
• The new Top Fuel has clearance for 2.5” tires; which makes perfect sense as even XC racers are now running 2.4” tires as standard.
• The downtube storage compartment is now featured on all Top Fuel models, including the alloy versions. It’s a great feature that often gets nixed on lower priced frame models.

Price: $11,500 Weight: 26.8lbs (size XL) Style: Full suspension 120mm trail bike Frame: OCLV Mountain Carbon, internal storage, tapered head tube, Knock Block 2.0, internal guided routing, downtube guard, magnesium rocker link, Mino Link, ABP, Boost148, 120mm travel Wheel Size: 29” Fork: RockShox SID Ultimate, DebonAir spring, Charger Race Day damper, tapered steerer, 44mm offset, Boost110, 15mm Maxle Stealth, 120mm travel Rear Shock: RockShox Deluxe Ultimate RCT, 185mm x 50mm Drivetrain: SRAM Eagle AXS, wireless, 12-speed Cranks: SRAM XX1 Eagle, DUB, 55mm chainline, 175mm length Chainring: 30 tooth Cassette: SRAM Eagle XG-1299, 10-52T, 12-speed Brakes: SRAM G2 Ultimate hydraulic disc, carbon levers Front Wheel: Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle Rear Wheel: Bontrager Line Pro 30, OCLV Mountain Carbon, Tubeless Ready, Rapid Drive 108, 6-bolt, SRAM XD driver, Boost148, 12mm thru-axle Tires: Bontrager XR4 Team Issue, Tubeless Ready, Inner Strength sidewalls, aramid bead, 120tpi, 29.x2.40'' Saddle: Bontrager Arvada, austenite rails, 138mm width Seatpost: RockShox Reverb AXS, 170mm travel, wireless, 34.9mm, 480mm length Handlebar / Stem: Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5mm handlebar rise, 820mm width, 0 degree stem rise, 45mm stem length

While XC race bikes were becoming longer travel, yet another new category of mountain bikes started to gain traction with riders: down-country. This new breed of bikes combines elements of longer travel all-mountain and trail bikes (such as slack geometry, more powerful brakes, and heavier casing tires) with shorter travel and lighter-weight frames. Essentially, burly XC bikes that you can ride all day, are efficient climbers, and very capable at descending. This is the approach Trek took with the latest Top Fuel.

The new Top Fuel strikes a similar silhouette to the older model, with a vertically mounted shock layout and Trek’s Active Braking Pivot suspension system; which now delivers an extra 5mm of travel in the rear to match the 120mm travel fork. The Top Fuel’s geometry is in line with other bikes in the emerging down-country category, with the headtube angle becoming 1.5 degrees slacker and reach increasing by 10mm as compared to the previous generation of the bike. The Top Fuel now also has clearance for 2.5 inch tires, for those who want to push traction to the limit.

The new Top Fuel edges ever closer into the territory of its longer travel sibling, the Fuel EX. The updated geometry of the Top Fuel actually makes the Fuel EX look a bit dated in comparison. The two bikes have identical headtube angles, with the Top Fuel having a longer reach and a steeper seat angle as well. You can even fit a 130mm fork on the Top Fuel, which would make it slacker than the Fuel Ex. Basically, the Top Fuel is no longer a race oriented bike. It has now morphed into an efficient trail bike for riders that still want solid pedaling performance to get up the climbs, but who want additional speed, confidence, and control on the descents.

Builds & Pricing

There are a total of nine different Top Fuel builds offered by Trek, plus carbon and alloy framesets. The Top Fuel is also available through Trek’s Project One program, allowing riders to customize everything from components to paint.

We got to test the Top Fuel 9.9 XX1 AXS build, which at $11,050 is (depending on your perspective) either a reasonable price for a modern high end bicycle or completely bonkers. With bikes such as Specialized S-Works Epic EVO coming in at a cool $13,000, and the Scott Spark 900 Ultimate EVO AXS at $14,000, the Top Fuel 9.9 almost seems price conscious.

The cheapest Top Fuel model, the alloy framed Top Fuel 5, features a RockShox Recon fork, X-Fusion X-Pro2 shock, and a Shimano Deore drivetrain at $2,630. The Top Fuel 7 has a Recon Gold fork with a mix of Shimano SLX and XT parts, plus Bontrager Line Comp wheels for $3,530. The Top Fuel 8 is the priciest alloy build at $3,830, with a RockShox SID fork and Deluxe Ultimate shock plus more powerful Shimano M6120 four-piston brakes.

The Top Fuel 9.7 is the most affordable of the carbon builds at $4,230. It uses Fox Rhythm 34 fork with a Float DPS shock and is finished with a mix of Shimano SLX and XT, plus Bontrager Line wheels. The Top Fuel 9.8 has three different versions based on your component preferences. You can go mechanical with SRAM GX or Shimano XT for $7,050 or upgrade to GX AXS for $7,550. All three use RockShox SID Select+ forks and Deluxe Ultimate RCT shocks, along with Bontrager Line Elite 30 wheels. Moving to the top of the price range, for $9,550Trek offers the Top Fuel 9.9 XTR build for Shimano and Fox lovers. It uses Fox Factory level suspension, a full mechanical XTR drivetrain, and Bontrager Line Pro 30 wheels. Riders preferring Rockshox Ultimate level suspension and electronic XX1 AXS shifting will need to spend $11,050 to get the most expensive Top Fuel model, the 9.9 XX1 AXS.

If you’d rather build your bike from the frame up, Trek offers alloy and carbon framesets. The Top Fuel AL frame sells for $2,320 with a Fox Float DPS shock. The carbon frame is priced at $3,720 and includes a Fox Factory Float DPS shock.

Geometry & Fit

The new Top Fuel has received the slacker and longer treatment, and as a result, the head tube angle is now a degree and a half slacker at 66º across the entire size range. Reach grows by 10mm while BB height and chainstay length remain the same from the previous generation.

Trek offers seven different sizes of the Top Fuel, including an M/L option for riders often caught between the medium and the large. With a stock stem length of 45mm on all sizes except an XS, our 6’3 tester felt cramped on the size XL and likely would have benefited from sizing up to an XXL. The issue was resolved with a longer stem, but the most expensive 9.9 builds of the Top Fuel Trek use its integrated Bontrager RSL handlebar and stem combo. It’s easy enough to swap out as it thankfully doesn’t run any lines internally, but it still means riders will need to supply both a bar and a stem to make fit adjustments. As always, it’s highly recommended that you get a test ride in at a shop before buying a new bike if possible.

Ride Impressions

The new Top Fuel is very much a short travel trail bike meant for ripping down burly trails. Thanks to a 40mm increase in wheelbase, a slacker head tube angle, and other geometry changes over its previous version, it feels much more planted and composed on rough and fast descents. It’s a bike that wants to hold a line and stay planted on the ground. This worked well in certain situations, like scrubbing speed on a rough bit of trail heading into a turn. Other times it made me have to fight the bike a bit to make quick line adjustments.

To highlight the new trail bike character of the Top Fuel, Trek has made some component choices to suit the bike's new intended purpose. Opting for four-piston SRAM G2 brakes, as well as grippier XR4 tires, for better control on steep descents. The frame is also beefed up with a larger downtube that now includes a storage compartment for snacks or, more likely, flat-fix tools. The seat tube also grows in diameter to increase stiffness and accommodate a larger diameter 34.9mm dropper post. The remote lockout is also gone from the handlebars – which, perhaps more than any other change, makes the Top Fuel's intent as a trail bike crystal clear.

Trek’s ABP suspension design has had many years of refinement and is a genuine four-bar platform, unlike many 120mm bikes that use a flex pivot. In contrast, all the pivot points on the Top Fuel use sealed bearings, resulting in a suspension setup that feels much more active. The design does a good job of isolating braking from the suspension, resulting in less skipping and bouncing when you’re hard on the brakes in a rough section of trail.

The downside of the Top Fuel’s trail bike transformation is that it’s now a bit heavy. Our premium 9.9 XX1 AXS XL sample came in at nearly 27 lbs. This isn’t wildly heavy for a trail bike, but typically you get a bit more suspension travel with that weight penalty. For reference, the Scott Spark I tested earlier this year has the same amount of suspension travel as the Top Fuel but is a full three pounds lighter. Trek does say that the Top Fuel is compatible with a 130mm fork, and I can’t help but think the new Top Fuel would have made a lot more sense with the increased travel straight from the factory.

After having multiple testers on the Top Fuel over the last few weeks, our consensus has been that the Top Fuel would thrive in a place that has a lot of machine built or well maintained, and steep trails. Trails where you can get the Top Fuel moving fast allow the progressive all-mountain geometry to shine and make the bike feel much more capable than its 120mm of travel would suggest.

The new Top Fuel is undoubtedly more capable than its previous version while maintaining much of its pedaling efficiency. Riders with more than a casual interest in racing should probably look at bikes such as the Scott Spark , Canyon Lux Trail , or Specialized Epic EVO . The Top Fuel is perhaps the ideal bike for riders who want a trail, or even all-mountain, bike geometry experience, but don't want the extra weight or need the extra bit of travel.

Trek Top Fuel 9.9 XX1 AXS

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Trek Top Fuel 9.8 review

Super-capable ripper on the racetrack or singletrack

Laurence Crossman-Emms

Ed Thomsett

Makes the climbs fun and rips on the way down; an elegant package with a choice of colours; the six frame sizes span a massive range

A higher front end would give more descending confidence; thin tyres don’t offer much grip or protection; carbon wheels and bar bump up the price without a big impact on performance

Trek’s ambition with the Top Fuel is to combine the best qualities of both cross-country and trail bikes. This genre-bending, 115mm-travel 29er is burlier than its XC thoroughbred, the Supercaliber , but lighter and more agile than the Fuel EX . It promises lightning-fast speeds, whether gravity is on your side or not.

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Trek Top Fuel 9.8 frame

The Top Fuel’s full-carbon frame is obviously a Trek design, with that familiar twin-triangle shape and ABP (Active Braking Pivot) suspension design, where the rearmost pivot is concentric with the rear axle.

As on the rest of Trek’s full-sussers, the ‘Full Floater’ shock mounting of the old Top Fuel is gone. Instead, the Fox DPS air-can mounts directly to the frame at one end and to a magnesium rocker link at the other. Travel has been extended by 15mm for 2020.

In terms of geometry, the Top Fuel is now longer and slacker. Depending on which way you position the Mino Link flip-chip, the head angle can be set at either 67.5 or 68 degrees and the reach varied by 5mm, from 470 to 475mm on the large.

The effective seat-tube angle has been steepened to 75/75.5 degrees. With six sizes, it should be easy to achieve a perfect fit. The details of the frame have been well considered too, from its sleek, flowing lines to the fully-internal cable routing and integrated rubber protection finish.

Plus, Trek’s Knock Block steering-lock stops the fork crown fouling on the down tube.

Trek Top Fuel 9.8 kit

That 115mm-travel, air-sprung rear end is matched to a 120mm Fox 34 Performance fork. A bar-mounted RockShox TwistLoc remote lets you lock out both ends simultaneously, providing a firm pedal platform that’s easy to toggle on or off.

Combine that with a Bontrager Line Elite dropper post, and the Top Fuel switches easily into downhill mode, although a 10mm-shorter stem and slightly wider bar would help the handling.

Shimano’s SLX brakes are good, but it doesn’t take much to find the limits of the 160mm rear rotor and the lever return was a little sluggish.

I found the Bontrager XR3 tyres slightly flimsy too. They’re efficient uphill but the low-profile tread isn’t great on unsurfaced trails and I sliced a hole in the thin casing on a fairly mellow descent.

The bike’s price tag isn’t insignificant either and, while the spec is solid, I’d happily lose the carbon wheelset and bar to save some money.

Trek Top Fuel 9.8 ride impressions

You have to bite your tongue before criticising a bike like this because by its versatile nature it’s never going to be the best of the best in any scenario. With this in mind, there’s very little to fault in the way the Top Fuel rides.

With a poised feeling on the pedals even in the lower/slacker setting, the bike blasts up hills with minimal effort and I rarely found I needed to use the lockout apart from on long fireroads.

As a trail bike, the Top Fuel puts on an impressive show and never faltered, even when hammered into turns or launched off drops. The suspension gives you a solid base to push into and I was surprised after the first ride to discover that it only has 115mm of travel.

The main limiting factor to this downhill prowess is the low front end. When things get steeper, you do notice you’re on a bike that’s also built for going fast up hills. The short head tube and low stack height are clear indicators of this, and while for general trail riding I found them a little low, this does allow the bar to be fully slammed for all-out XC attacks.

Even with the 13-degree-rise stem positioned as high as possible on the steerer, I wouldn’t have minded a little more height. But then, upping the fork travel would blur the lines between the Top Fuel and the longer-travel Fuel EX.

On a bike like this, there are always going to be trade-offs, and opinion is always going to be biased by riding style, but for rapid mile-munching that doesn’t get in the way of enjoyment on the descents, the Top Fuel is hard to beat.

Trek Top Fuel 9.8 geometry (based on high setting for size L)

• Seat angle: 68.5 degrees
• Head angle: 68 degrees
• Chainstay: 43.3cm / 17.05in
• Seat tube: 47cm / 18.5in
• Top tube: 63cm / 24.8in
• Head tube: 10cm / 3.94in
• Fork offset: 4.4cm / 1.73in
• Trail: 10.3cm / 4.06in
• Bottom bracket drop: 2.9cm / 1.14in
• Wheelbase: 1,185mm / 46.65in
• Stack: 59.9cm / 23.58in
• Reach: 47.5cm / 18.7in

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2022 Trek Top Fuel

Wheel Size:

• XS: 27.5’’
• S–XXL: 29’’

Travel: 120 mm rear / 120 mm front

Material: Aluminum and Carbon versions available

• Aluminum frame w/ Fox DPS Performance shock : $2,300 USD / $2,900 CAD
• Carbon frame w/ Fox DPS Factory shock: $3,700 USD / $4,600 CAD
• Complete bikes $2,600 to $11,000 USD / $3,450 to $14,650 CAD; see below for details

When Trek first launched the Top Fuel in 2004, it was a dedicated XC race bike, and it stayed in that camp through several subsequent generations. In 2019, Trek nudged the Top Fuel a bit closer to the Trail category since the Supercaliber took over as their XC race full-suspension bike, but with just 115 mm of rear travel and XC-oriented geometry, that Top Fuel didn’t stray too far from its roots.

However, the all-new 2022 Top Fuel looks to add a big dose of Trail-bike capability, and features a bunch of interesting design details, too.

The overall layout of the Top Fuel hasn’t changed much from the prior iteration. It still uses Trek’s ABP suspension layout (a four-bar arrangement with a pivot concentric to the rear axle) with a vertically-oriented shock, and it’s still available in both aluminum and carbon versions. Both feature threaded bottom bracket shells, internal cable routing, and a storage port in the downtube. A water bottle does fit inside the front triangle on all sizes, but Trek says the XS is limited to a 15-oz one, and the Small can only accommodate a 20-oz bottle.

Both frame versions also feature Trek’s Knock Block 2.0 steering limiter, which has now increased the turning range to 72 degrees. Trek originally introduced the system to allow for a bigger downtube that would interfere with the fork crown if the bars got turned too far, but the new Top Fuel has no such limitation. Similar to the latest Trek Slash , the Knock Block system carries over on the Top Fuel to protect the cables from getting yanked on in a crash, but it can be removed if desired. There’s also ample rubber protection on the chainstay, seatstay, and downtube. A flip chip (Trek calls it a “Mino Link”) toggles between two geometry positions, which we’ll outline in more detail below.

Fit & Geometry

One of the most exciting details about the Top Fuel is that it’s offered in a whopping seven different frame sizes, ranging from XS through XXL, with a M/L snuck in the middle. This means that there’s both an especially wide range of sizes available, and that the jumps between sizes are a little tighter than average in the middle part of the range. And like we just saw from Rocky Mountain on their new Element — a bike that is squarely in competition with the new Top Fuel — the XS size Top Fuel gets 27.5’’ wheels, while the rest of the range rolls on 29’’ ones. That makes a lot of sense, for all the same reasons that we talked about in our First Look of the Element — shorter riders generally have less butt-to-tire clearance, and a shorter front wheel and fork makes it a lot easier for shorter folks to appropriately weight the front wheel, too.

The Top Fuel’s headtube angle sits at 66° in all sizes, and that’s paired with a 76° effective seat tube angle and 435 mm chainstays across the board. Reach ranges from a very short 400 mm to 520 mm across the size range. Interestingly, instead of doing neat 20 mm jumps between each size, Trek opted for a 30 mm jump between the Small to Medium, then tightened things to 15 mm between the Medium to M/L and the M/L to Large (the M/L frame’s reach clocks in at 465 mm). All those numbers are stated in the low position with the stock 120mm-travel fork; the high position steepens things by 0.4°, and Trek also condones running a 130mm-travel fork, which slackens both angles by 0.5°. For reference, here’s the full geometry chart:

There’s a huge range of geometry in modern ~120mm-travel bikes, from heavily XC-derived models to quite aggressive options (usually spec’d with a longer-travel fork), and the new Top Fuel sits somewhere in the middle of that range. Given how Trek has talked about the bike, that makes a lot of sense — this is supposed to be a bike for people who want a very sprightly, efficient bike with a solid dose of downhill capability for when things get rougher, and the Top Fuel slots in neatly there. It’s notably similar to the Transition Spur and Pivot Trail 429 , and just a touch less aggressive than the brand new Rocky Mountain Element and Guerrilla Gravity Trail Pistol — all strong contenders in this category.

Trek offers the Top Fuel in nine different builds, with prices ranging from $2,600 to $11,000, and there’s a great range of SRAM and Shimano options across a big spectrum of price points. And bonus points to Trek for sticking to Shimano on the least expensive few options — as we’ve discussed several times this past year , SRAM’s mid-to-high-end options work great, but Shimano has a clear advantage on the more budget-oriented end of the spectrum.

For reference, the complete build options are as follows:

• Fork: RockShox Recon Silver RL
• Shock: X-Fusion Pro 2
• Drivetrain: Shimano Deore
• Crankset: Shimano MT512
• Brakes: Shimano MT200
• Wheels: Bontrager Alloy
• Dropper Post: TransX
• Fork: RockShox Recon Gold 130 mm
• Shock: Fox DPS Performance
• Drivetrain: Shimano SLX shifter / XT derailleur / Deore cassette
• Crankset: Shimano Deore
• Brakes: Shimano MT4100
• Wheels: Bontrager Line Comp 30
• Fork: RockShox SID
• Shock: Fox Float DPS Performance
• Drivetrain: Shimano XT w/ SLX cassette
• Brakes: Shimano M6100
• Fork: Fox 34 Rhythm
• Drivetrain: Shimano XT w / SLX cassette
• Fork: RockShox SID Select+
• Shock: RockShox Deluxe Ultimate
• Drivetrain: Shimano XT
• Crankset: Shimano XT
• Brakes: Shimano XT 4-piston
• Wheels: Bontrager Line Elite 30 Carbon
• Dropper Post: Bontrager Line Elite
• Drivetrain: SRAM GX
• Crankset: SRAM GX
• Brakes: SRAM G2 RS
• Drivetrain: SRAM GX AXS
• Fork: Fox 34 Factory Step Cast
• Shock: Fox Float DPS Factory
• Drivetrain: Shimano XTR
• Crankset: e*Thirteen TRS Race
• Brakes: Shimano XTR 2-piston
• Wheels: Bontrager Line Pro 30 Carbon
• Fork: RockShox SID Ultimate
• Drivetrain: SRAM XX1 AXS
• Crankset: SRAM XX1
• Brakes: SRAM G2 Ultimate
• Dropper Post: RockShox Reverb AXS

Some Questions / Things We’re Curious About

(1) On paper, the Top Fuel looks like it’ll slot in somewhere between the most XC-derived 120mm-travel bikes and the most aggressive options in the class, but does that prove true on the trail?

(2) As shorter-travel Trail bikes get more and more capable, should more people who’d previously be shopping in a longer-travel category be looking at these sorts of options, including the Top Fuel?

Bottom Line (For Now)

Trek looks to have done a great job of modernizing their longstanding Top Fuel model, and in turn, bridging the gap between the Supercaliper XC race bike and the Fuel EX Trail offering. We’re hoping to get on one to see how it stacks up in a rapidly-growing field of contenders in that space, and will have a full review to come if we can make it happen.

2 comments on “2022 Trek Top Fuel”

Looks like a good all round option for up and down performance. I’d like to try it with a 130 mm fork in the high setting.

I have the 2022 Fuel EX7, I’m a xc type rider and do about one 50 mile ride per week on this bike. I went with the EX model because I like having the extra travel, however I wish I would have gotten the EX8 XT model and then just changed out the wheels and shifting for Sram GX 12 speed. The NX Sram has the DUB crankset and bottom bracket and there’s no thread together bottom bracket for this setup and the NX cassette is a boat anchor. So far I’ve put on lighter tires, seat post, and cassette and having a much lighter wheelset built for it now. I thought I would have been using the shock leavers but I just leave those full open 99% of the time these bikes handle great.

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