2025 Trek Top Fuel
Wheel Size:
- 27.5’’ (Size S),
- 29’’ (Size M–XL); compatible with 27.5’’ rear wheel
Travel: 120 mm rear / 130 mm front (130 mm rear with 55 mm stroke shock, accepts up to 140 mm fork)
Geometry Highlights:
- Sizes Offered: S, M, ML, L, XL
- Headtube Angle: 65.5° (Low) / 66° (High)
- Reach: 462 mm (size ML, Low) / 467 mm (size ML, High)
- Chainstay Length: 440 mm (size ML)
Frame Material: Aluminum and carbon fiber versions available
Price:
- Complete bikes starting at $2,699 USD / $3,599 CAD
- Framesets starting at $2,449 USD / $3,349 CAD
Blister’s Measured Weight (Top Fuel 9.9 XX, size L, w/o pedals): 28.62 lbs / 12.89 kg
Test Location: Washington
Reviewer: 6’, 165 lb / 183 cm, 74.8 kg
Test Duration: 3 months
Intro
Trek’s lineup of XC and Trail bikes, spanning the Supercaliber, Top Fuel, and Fuel EX, span an impressively wide range of use cases, allowing riders to pick exactly the sort of bike that suits their style. So when Trek invited us to get a first look at their new 4th generation of the Top Fuel, one of our first questions was just how much it had changed from the prior version, and whether there’d be more overlap with its siblings on either end of the spectrum.
With the updated Top Fuel, Trek wanted to push the versatility envelope by offering more adjustability, but without losing the energetic spirit of the Gen 3 Top Fuel that made it such a popular bike in the shorter travel Trail bracket. So let’s see how they’ve gone about it.
The Frame
While the Gen 4 Top Fuel sticks to a similar overall layout and silhouette as the prior version, it is an all-new frame, and a lot of the details have been updated. The first notable change is the substantial drop in frame weight, with both the aluminum and carbon models seeing a 220-gram weight reduction. That’s even more impressive considering that the new bike is also more adjustable, with a 4-position Mino Link chip at the lower shock mount rather than the outgoing model’s 2-position chip.
The 4-position Mino Link keeps the Low and High modes of the prior Top Fuel, while also adding a suspension progressivity adjustment that functions independently of geometry adjustment. The forward mount is a more linear option with 14% progressivity (similar to the outgoing model), while the rearward mount jumps to 19% progressivity for more support. Anti-squat has been increased slightly over the prior version as well.
Speaking of suspension, the Top Fuel still uses Trek’s longstanding ABP layout (essentially a linkage-driven single-pivot with a dropout-concentric pivot to provide better control of the braking characteristics). While the stock configuration still gets 120 mm rear travel, Trek confirmed that a longer stroke 185 x 55 mm shock (stock is 185 x 50 mm) can be used to increase travel to 130 mm out back. The new Top Fuel also comes with a 130 mm fork across the board and can accept up to a 140 mm one, allowing riders to bump up the suspension travel for a touch more capability on rougher trails.
Thanks to that compatibility with the longer travel fork, the Top Fuel is able to accept a mixed wheel setup in sizes M–XL. Trek recommends counteracting that smaller 27.5’’ rear wheel by using a 140 mm fork and keeping the Mino Link in the High position, though there’s no real reason you couldn’t try it with the stock 130 mm fork if you wanted to make things a touch steeper and lower.
The new Top Fuel also gets an improved in-frame storage system, with better sealing from the elements and a larger, less snag-prone opening. Trek also designed new storage bags to accompany the updated storage hatch, with the carbon frame getting a pair of bags (one padded, one unpadded) while the aluminum one gets just the padded bag.
As a final note, Trek has bid farewell to Knock Block on the latest Top Fuel. The headset is a standard tapered affair, which should make parts a bit easier to source.
Fit & Geometry
Trek clearly approached the Top Fuel refresh with an “if it ain’t broke, don’t fix it” attitude, and given the success of the prior bike, that’s likely good news to a lot of folks. The Medium-Large gets a 462 mm reach in the Low position, and the headtube angle has been slackened by 0.5° to 65.5° in the Low setting and 66° in High. The seat tube angle remains the same as the prior model at 76°.
The big change (and one we’re excited to see) is the addition of size-specific chainstays. Where the prior Gen 3 Top Fuel had static 435 mm chainstays across sizes, the Gen 4 gets 435 mm chainstays on the S and M sizes, 440 mm on Medium-Large and Large, and 445 mm on XL. Size-specific chainstays help to keep fore/aft balance the same across sizes for consistent ride quality, and we’ve found this theory to be both noticeable and beneficial on the trail.
As a final note, Trek says that they have improved dropper post insertion depth with the new frame, but we don’t have the exact numbers on the new insertion depth or what length dropper posts ship with each size.
Full geometry figures for the Top Fuel’s various configuration options are included in the charts below:
The Builds
Trek is offering three aluminum and four carbon-framed builds for the Top Fuel, leaving riders with quite a bit of choice as far as spec level and frame material. Build kits are all supplied with 130 mm forks from Fox and RockShox, as well as a mix of SRAM and Shimano drivetrains depending on the spec level. All of those details are included below.
In typical Trek fashion, wheels and finishing bits are their in-house Bontrager brand. The carbon-framed models get a potentially polarizing RSL Integrated carbon fiber stem and bar combo, which is undoubtedly lightweight but does mean bar roll can’t be adjusted. On the tire front, Trek has been investing in some new tire designs and compounds for the Bontrager tires, which have been promising in some of our early experiences. That said, it’s a bit disappointing to see cheaper wire bead tires supplied on the aluminum models.
Highlights from each model’s available builds are as follows:
- Drivetrain: Shimano Deore M6100
- Brakes: Shimano MT200
- Fork: RockShox Recon Silver RL (130 mm)
- Shock: X-Fusion Pro 2
- Wheels: Bontrager Line 30
- Dropper Post: TranzX JD-YSI22
- Drivetrain: Shimano SLX/XT
- Brakes: Shimano Deore M6120
- Fork: Fox 34 Rhythm (130 mm)
- Shock: Fox Float Performance
- Wheels: Bontrager Line Comp 30
- Dropper Post: Bontrager Drop Line MaxFlow
- Drivetrain: SRAM GX Eagle AXS
- Brakes: SRAM Level Bronze
- Fork: Fox 34 Rhythm (130 mm)
- Shock: Fox Float Performance
- Wheels: Bontrager Line Comp
- Dropper Post: Bontrager Drop Line MaxFlow
- Drivetrain: Shimano XT
- Brakes: Shimano XT M8120
- Fork: RockShox Pike Select+ (130 mm)
- Shock: RockShox Deluxe Ultimate RCT
- Wheels: Bontrager Line Comp
- Dropper Post: Bontrager Drop Line MaxFlow
- Drivetrain: SRAM GX Transmission
- Brakes: SRAM Level Bronze
- Fork: RockShox Pike Select+ (130 mm)
- Shock: RockShox Deluxe Ultimate RCT
- Wheels: Bontrager Line Comp
- Dropper Post: Bontrager Drop Line MaxFlow
- Drivetrain: SRAM XO Transmission
- Brakes: SRAM Level Silver
- Fork: RockShox Pike Ultimate (130 mm)
- Shock: RockShox Deluxe Ultimate RCT
- Wheels: Bontrager Line Pro
- Dropper Post: RockShox Reverb AXS
- Drivetrain: SRAM XX Transmission
- Brakes: SRAM Level Ultimate
- Fork: RockShox Pike Ultimate (130 mm)
- Shock: RockShox Deluxe Ultimate RCT
- Wheels: Bontrager Line Pro
- Dropper Post: RockShox Reverb AXS
In addition to the complete bikes, Top Fuel framesets are available in both aluminum and carbon. Asking prices are $2,449 USD / $3,349 CAD for the aluminum option and $3,899 USD / $5,349 CAD for carbon.
FULL REVIEW
The Trek Top Fuel has evolved quite a bit over the years. The original was a 100mm-travel XC race bike, back when 26’’ wheels were still standard. After a few years’ hiatus, it returned as an updated XC race bike, that time with 29’’ wheels but still rocking 100 mm of travel at both ends and steep, compact geometry. When the third-generation bike rolled around, Trek had launched the Supercaliber as their full-suspension XC race bike, which left some room to bump the Top Fuel up in travel and intended use. That version was much more of a short-travel, XC-derived Trail bike than a dedicated race weapon. It still aimed to be light and efficient, but less ruthlessly so, and picked up some descending capability and comfort in trade.
Given that history, when the new fourth-generation Top Fuel launched earlier this year, I was curious to see if they’d made another sea change in its design, or just tweaked and refined the recipe of the gen-three bike. I’ve now spent a bunch of time on the new Top Fuel and am ready to weigh in.
Fit & Sizing
David Golay (6’, 165 lb / 183 cm, 74.8 kg): I had an easy time getting comfortable on the size Large Top Fuel, and at no point was I tempted to try a different frame size. Trek’s recommended sizing range puts me squarely in the middle of the band for the Large frame, just outside the overlapping regions for the ML and XL frames, and that feels spot on.
The only real change I needed to make was to trim down the Bontrager RSL integrated bar / stem from its colossal 820 mm original width. That done, I was quickly at home on the Large Top Fuel. Its overall sizing is a little more compact than I might prefer on a burlier, more gravity-oriented sort of bike, but it feels in keeping with the intentions of the Top Fuel and the kinds of terrain in which it thrives.
As is common for bikes in this class, the Top Fuel feels most balanced with the bars relatively low, and its preferred body positioning feels distinctly XC-derived. As we’ll get into in more detail below, I think Trek has done a nice job of making a relatively XC-oriented sort of Trail bike that’s very efficient and snappy, but a bit more composed and comfortable than a true XC race bike (even as those race bikes are becoming more capable descenders). The Top Fuel’s fit and the body positioning that it favors are a real part of that, and Trek has made a cohesive overall package here.
Climbing
I’ll start with a big claim: the Top Fuel is the best climbing bike I’ve been on this year. Granted, I haven’t been the one to test the true XC race bikes we’ve had in for review (Full Reviews of both the Cannondale Scalpel and Yeti ASR are coming soon), but the Top Fuel is very impressive.
What makes the Top Fuel really stand out is the way that it manages to be very efficient and responsive, first and foremost, while also offering just a little bit better traction and small-bump sensitivity under power than anything I’ve been on in recent memory that can match its pedaling efficiency. That’s not to say that the Top Fuel is some ultra-cushy bike by any stretch. It’s very efficient and XC-derived at its core, just with a little extra compliance baked in.
At least for folks with the right preferences, that’s a great recipe. There are (mostly longer-travel) bikes that fare better if you want to specifically prioritize traction and get a really grippy, forgiving ride on the way up. However, those sorts of bikes aren’t nearly as efficient and snappy as the Top Fuel, particularly if you’re really trying to push the pace and climb quickly, rather than just grinding your way to the top. The Top Fuel is happy to put the hammer down if you want to, but it is a little more compliant and grippy than most bikes that I’d say similar things about.
I wouldn’t mind the Top Fuel’s seat tube being a touch steeper when climbs start getting really steep, but realistically, the Top Fuel is a bike that’s going to be ridden on a lot more rolling, varied terrain than big winch-and-plummet type trails. So, I think the balance that Trek has struck is pretty reasonable.
Part of that preference on my part is almost certainly down to the fact that I spend a lot of time on bigger Enduro bikes with (appropriately) steeper seat tube angles, and I’m just used to / have developed muscles for the seated pedaling position that those sorts of bikes produce. I didn’t have trouble keeping the front wheel of the Top Fuel planted or anything like that. But there were a few instances when things got super steep and I just felt a bit more hunched over and off the back of the bike than I wanted to be for maximum pedaling efficiency and comfort.
In the sort of terrain that it’s most intended for, though, the Top Fuel climbs extremely well. It’s quite efficient while offering just a bit more traction and compliance than most bikes that can match its efficiency. The pedaling position is great on all but the steepest climbs, and its handling is pretty quick without feeling twitchy and hard to manage. Good stuff all around.
Descending
The same general traits that serve the Top Fuel so well on the way up also make it a lot of fun on the way back down — on the right trails. Unsurprisingly, there are many burlier, longer-travel bikes that are better suited to steep, technical descents, but the Top Fuel is a ton of fun on faster, flowier descents in particular.
As tends to be the case with bikes in this class, the Top Fuel makes it especially easy to build and maintain speed on trails that don’t have a ton of pitch. It lets you make the most of quick pedal strokes when you’re able to take them, rewards pumping through terrain features, and simply rolls quickly the rest of the time. But, as with its climbing performance, the Top Fuel stands out for being just a touch more composed and forgiving (in terms of its suspension performance) than most of the bikes that it compares most directly to on paper.
That’s particularly noticeable when carrying a bunch of speed into a rougher section of trail. The Top Fuel just feels a little more settled and composed in those situations than most bikes that aren’t longer-travel and more stable overall. If you’re riding a lot of consistently fast, rough trails, the Top Fuel starts to feel undergunned fairly quickly — we’re talking about an XC-derived 120mm-travel bike, after all. It also takes a lot of very precise, dynamic riding to maintain speed in extended rough, fast sections. But every bike I can think of that’s substantially better than the Top Fuel in really burly terrain is also less efficient, less lively, and less fun on the sorts of trails the Top Fuel is best suited for. Come in with reasonable expectations for what you’re getting, and the Top Fuel is quite impressive.
On more moderate trails, the balance and weight distribution of the Top Fuel feels pretty neutral, and it’s got a relatively big sweet spot for what it is. When things start getting properly steep, its low front end starts to feel more pronounced, and the Top Fuel’s sweet spot shrinks as you get pulled forward on the bike. But, again, the fit and body positioning of the Top Fuel feel well-suited to the bike’s intentions.
My preferred setting for the Top Fuel’s flip chip was in the low / more progressive setting, but the tweaks it makes are relatively subtle; all four combinations feel entirely reasonable. The low setting makes the Top Fuel a touch more stable and, more significantly, makes its sweet spot feel a little bigger, putting you more “in” the bike. The high setting increases pedal clearance a touch and sharpens up the handling a little. The more progressive setting improves small-bump sensitivity and bottom-out resistance, while the less progressive one makes the Top Fuel slightly more lively and efficient. It’s a nicely sorted-out set of adjustments that will let folks tweak the bike’s performance to suit their preferences without being able to go off the deep end.
The Build
Unsurprisingly, the $10,500 Top Fuel 9.9 XX that I tested leaves little to be desired when it comes to the build. The SRAM XX Transmission works great, and the RockShox Pike Ultimate fork / Deluxe Ultimate rear shock are particular highlights for this class of bike. That suspension duo offers more consistent damping and better high-speed support than most similarly lightweight options, and the Pike fork chassis is impressively stiff for its weight.
The SRAM Level 4-piston brakes (with 180 mm rotors) that come stock on this build are not especially powerful, but even as someone who likes (and is used to) much more powerful ones, I found them to be fine on the sorts of trails where the Top Fuel is most in its element. The Level brakes started to feel like a limitation when I pushed the Top Fuel into some steeper trails (ones where most folks are on at least ~150mm-travel Trail bikes, if not full-on Enduro ones). Again, that’s not what the Top Fuel is for. I wouldn’t have been mad if Trek had bumped the brakes up to Codes, but I’m not mad about the Levels, either.
If I were looking for the best bang-for-buck in a still very fancy Top Fuel build, I’d have a hard time looking past the 9.9 XTR (MSRP: $6,999). It gets you the same wheels, tires, suspension, and almost the same finishing components as the 9.9 XX, apart from steel rails on the saddle (in lieu of carbon on the 9.9 XX), and a Bontrager-branded dropper in place of the fancy RockShox Reverb AXS. The Shimano XTR drivetrain (with an e.13 carbon crank) isn’t the new hotness in the same way that the SRAM XX Transmission is, but it still shifts wonderfully. Plus, the 9.9 XTR build saves you $3,500 and about half a pound of weight, according to Trek’s stated specs. That’s a no-brainer in my book.
I also tried running the Top Fuel in long-travel mode by putting a 140 mm air shaft in the stock RockShox Pike fork and swapping in a 55mm-stroke Fox Float shock for a few rides. The changes were pretty much what you’d expect, and more of a slight tweak than a massive sea change in how the Top Fuel rides. The increased travel made the Top Fuel a little more planted and composed in its suspension performance, a touch less lively and efficient, and slightly less sharp in its handling due to the taller fork / slacker headtube angle.
None of those changes were huge, and the Top Fuel feels pretty coherent with either setup. Personally, I preferred the stock 120 mm rear / 130 mm front travel combo for its slightly sharper handling and more lively feel. Going with more travel makes the Top Fuel a little more cushy and forgiving of mistakes, which will undoubtedly be welcome for some folks; for me, it felt more like trying to turn the Top Fuel into a bigger, burlier bike than it actually is. The lively suspension performance and sharp handling are some of the Top Fuel’s biggest strengths, and I think most folks who want to make the Top Fuel more planted and composed would just be better served by a longer travel, more stable bike.
I had similar feelings about the Top Fuel’s mixed-wheel configuration. Trek recommends pairing the smaller rear wheel with a 140 mm fork and the high position on the flip chip to keep the bottom bracket from getting super low, but that still slackens out the bike a bit. More significantly, that setup moves the bike’s weight bias forward and shrinks the sweet spot for moving around on the bike in the process. It works, but the Top Fuel feels a bit less cohesive in that configuration.
The Top Fuel’s downtube storage is also welcome, and the latch mechanism is both secure and easy to use. However, the opening isn’t particularly wide, and the frame’s relatively slim downtube means it’s not the roomiest. It’s plenty useful for stowing a tube, snacks, tools, and other smaller items, but you’ll be hard-pressed to stuff a jacket in there, for example.
Who’s It For?
The Top Fuel is a great option for folks who want a very efficient Trail bike that they’ll use for covering big miles quickly, but that’s more composed, fun, and less fatiguing on the way down than most true XC bikes. The Top Fuel is also a promising choice for riders who just want a particularly lively, energetic bike to make mellower trails exciting while still being able to handle a burlier one on occasion. The Top Fuel is quicker handling and more efficient than most bikes with more suspension travel, and it’s a little more composed on steeper, rougher terrain than most of the bikes it most directly compares to on paper. That will be a perfect Goldilocks middle ground for a bunch of folks.
Bottom Line
Making a short-travel, XC-derived Trail bike that’s light, lively, and efficient while also being significantly more composed and forgiving than true XC race bikes on descents is a tricky balancing act, but I’ve clicked especially well with how Trek has gone about that task.
The fourth-generation Top Fuel isn’t pretending to be something it isn’t — Trek isn’t going overboard in how they talk about its descending capabilities or anything like that. But that clarity of purpose helps make the Top Fuel so good at what it does. Of the bikes in its class that I’ve tried, the latest Top Fuel is my current favorite.
Deep Dive Comparisons
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Deep Dive: 2025 Trek Top Fuel
We compare the Trek Top Fuel to the prior-generation Top Fuel, Specialized Epic Evo, Rocky Mountain Element, Transition Spur, Santa Cruz Tallboy, Revel Rascal V2, Pivot Trail 429, and Forbidden Druid V2
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I’m debating on buying a Top Fuel. I’m currently on a Guerilla Gravity Trail Pistol and thought your review on that bike was spot on. You mentioned it wasn’t sprightly in its pedaling and I completely agree. However I do enjoy it’s descending abilities. How would you compare this Top Fuel to the Trail Pistol?