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
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.
Some Questions / Things We’re Curious About
(1) Trek took a measured approach in updating the Top Fuel from a geometry perspective, but the added adjustments and other updates seem quite significant. Does the Top Fuel still fit smack in the middle between the Supercaliber and Fuel EX, or do the changes push it toward the more descending-oriented side of things?
(2) What tradeoffs does the option of long-shocking the Top Fuel to 130 mm of rear travel bring? What about bumping the fork to 140 mm?
Bottom Line (For Now)
The Top Fuel received all kinds of acclaim when it was last updated a few years ago — the Gen 4 has big shoes to fill. On paper, Trek’s efforts to cut weight, add adjustment options and tweak geometry should give fans of the outgoing Gen 3 little to complain about, while also expanding the Top Fuel’s appeal to other folks who wanted something just a touch more aggressive. We’ve been having a boatload of fun on some of the latest lightweight Trail bikes to hit the market, and we’re happy to have the opportunity to put the Top Fuel to the test over the coming months to see how it stacks up against its competitors.
Flash Review: Our Initial On-Trail Impressions
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Flash Review — 2025 Trek Top Fuel
The new Trek Top Fuel aims to compete with a crowded class of light, efficient shorter-travel Trail bikes including the Specialized Epic Evo, Rocky Mountain Element, and Santa Cruz Tallboy. Check out our early impressions of how the Top Fuel stacks up.
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