Technically, the two contenders share a parallel history. Both the FOX 38 and the RockShox ZEB launched in 2020 with the same ambition: to bridge the gap between classic single-crown enduro forks and dual-crown models. Since then, both have evolved steadily, each receiving significant updates along the way.
By the way: You can find the individual reviews of both forks via the following links. There you’ll also find all information on the different models and prices.
Review: FOX 38 Factory GRIP X2
Review: RockShox ZEB Ultimate
Over the past few months, we’ve ridden different variants of the new FOX 38 Factory GRIP X2 and RockShox ZEB Ultimate. From Queenstown to Tremp, Sintra, Finale Ligure, the Black Forest, and our home trails around Stuttgart, we tested the forks on a wide variety of terrain and bikes. To highlight the subtle differences between these two heavy hitters, we also tested them back-to-back in the Palatinate Forest. To keep things honest, we had two experienced test riders swap between both forks throughout a full day of riding, with base setups refined before the test began. Riding them back to back largely eliminates the usual variables: changing trail conditions, rider condition and creeping fatigue.
With a mix of high-speed sections, tight technical switchbacks, man-made berms, and jumps, our test tracks in the Palatinate offer the ideal conditions. They also provide a good mix of flat and steep sections, hard braking zones, fast jumps, and solid G-outs to evaluate the forks in every conceivable situation.
As visible in some of the photos, we also used a BYB V3 Pro telemetry system during the test. The data collected before, during and after the shootout gives us a lot to work with on both forks and their damping systems, but the findings still need more time and analysis before we can draw solid conclusions. We will be publishing everything in a separate article down the line. In this shootout, we focus purely on what the trail told us.
The Hard Facts in Detail: FOX 38 Factory vs. RockShox ZEB Ultimate
The New FOX 38 Factory GRIP X2 2027
The current 29″ variant of the FOX 38 Factory with 170 mm of travel tips the scales at 2,412 g. Visually, it follows the brand’s new design language, most recognisable in the revised cutouts on the crown, while remaining largely identical to its predecessor above the lowers. For offset, riders can still choose between 37 mm and 44 mm.
The technical centerpiece is the revised GRIP X2 damper. As before, it offers the full range of external adjustments with low-speed compression (LSC) and high-speed compression (HSC), as well as low-speed rebound (LSR) and high-speed rebound (HSR). To further minimize internal friction, FOX’s engineers rely on the new NA3 GlideCore air spring. A proven mechanical feature remains the floating axle: this system allows the axle to be tightened without putting stress on the lowers, minimising friction between stanchions and lowers.
The accessories have been thoughtfully updated too. The fender system comes in a short or the excellent longer version, aligns with the FOX 36 introduced last year and now bolts directly onto the fork. The pressure relief valves have been revised and are no longer part of the fender mounting. Volume spacers continue to be used to fine-tune the air spring curve. You can find more details in our in-depth individual review of the FOX 38 Factory fork.
The New RockShox ZEB Ultimate 2027
The current 29″ version of the RockShox ZEB Ultimate with 170 mm of travel weighs 2,540 g – which makes it around 100 g heavier than the FOX. Visually, the fork presents a very rectangular, aggressive look. A striking detail is the small cutout on the casting, reflecting SRAM’s current design trend – similar to the X0 crank or the new Maven brake levers. For offset, RockShox continues to use the standard 44 mm.
At the heart of the new ZEB sits the updated Charger 3.2 damper cartridge. Unlike the FOX damper, it offers external adjustment of low-speed and high-speed compression as well as low-speed rebound. In other words, you cannot adjust rebound speeds separately. The big innovation on the ZEB Ultimate, however, is the LinearXL air spring unit and the new proprietary AirAnnex.
To adjust end-stroke progression, the fork features the newly developed ABO system (Adjustable Hydraulic Out), which regulates progression over the last 7–17 mm of travel. Tokens can still be used as usual to fine-tune the air chamber. Also new is the position and design of the pressure relief valves, which have moved from the lowers up into the crown. And there is more to unpack. For a full breakdown of innovations like ButterWagon technology and everything else that has changed, our detailed individual review of the RockShox ZEB Ultimate is worth a read.
The Showdown on the Trail: FOX 38 Factory vs. RockShox ZEB Ultimate
Feel, Usability & Build Quality
When it comes to user-friendliness, the RockShox ZEB Ultimate clearly takes the lead. The adjusters impress with defined detents and clear acoustic feedback. Particularly practical: thanks to the LSC and HSC labeling, you can immediately see which position you’re in. On the FOX 38 Factory, only the rebound adjusters can match the ZEB’s tactile quality. The HSC adjustment feels vague, and while the LSC is better defined, the unpleasantly sharp edges of the adjusters stand out negatively.
RockShox also lead when it comes to the details. While the brake hose clamp of the FOX is made of plastic and isn’t positioned optimally on the fork, RockShox use a high-quality aluminum clamp. The air caps are worth a closer look too. FOX’s version sits low and sharp-edged, which makes it harder to grip than it should be. RockShox, as with the clamp, opts for the more ergonomic approach.
Another smart detail is the plastic cover on the ZEB’s brace, which protects the grid structure from dirt when no fender is mounted. In addition, the RockShox bolts provide better power transfer, as the Allen key sits much deeper in the head than on FOX’s shallow button-head screws, significantly reducing the risk of rounding. A similar picture emerges with the pressure relief valves: the ZEB’s valves provide better feedback. Notably, air escaped noticeably after almost every ride. On the FOX, much more finesse is required; if you press the pin too far, often nothing happens.
Small-Bump Sensitivity & Noise
In these disciplines, both contenders operate at an extremely high level and are absolutely on par. With the new NA3 GlideCore unit, FOX has taken a massive step forward: the fork is not only noticeably quieter but also responds much more sensitively. The frictional feel that could sometimes be perceived on the previous model has completely disappeared.
The ZEB was already extremely quiet in the previous generation and offered excellent sensitivity. In direct back-to-back comparison, no significant differences can be detected between the two contenders: both forks operate silently and with buttery-smooth breakaway force.
Function of the Adjustments
The RockShox ZEB Ultimate is intuitive to set up, and changes are immediately noticeable. The high-speed compression in particular shows its effect: at a setting of -2, you sit much deeper in the travel than at +2. You can feel every click. Positively, the zero position for LSC and HSC already offers an excellent baseline with correct air pressure. The rebound also offers a very wide range, and the ABO system (Adjustable Hydraulic Out) allows effective adjustment of end-stroke progression over the last 7 to 17 mm, even though the bottom-out bumper is very firm, which is why we usually left it at the very end of the travel.
On the FOX 38 Factory, changes in HSC are less pronounced. On top of that, the fork generally rides higher in its travel, which provides a noticeable boost in confidence, especially in steep terrain. However, you also have fewer adjustment steps to vary ride height. The rebound range is also significantly smaller in direct comparison. While FOX offer slightly finer increments with 18 clicks for LSC compared to the ZEB’s 15 clicks, the overall range remains roughly the same. Due to the more noticeable effect of each click and easier handling, RockShox still comes out ahead here, and both the base setup and fine-tuning are simply more enjoyable on the ZEB.
Ride Character
On the trail, both forks reveal their own character. The ZEB feels more lively and “poppy” than the FOX encouraging you to play with the terrain while still generating massive traction. In the HSC zero setting, it sits slightly lower in the travel than its competitor, but releases its travel more eagerly than its predecessors.
The FOX 38 Factory, on the other hand, embodies the “vacuum cleaner principle.” It sits extremely planted on the trail and absorbs bumps almost unnoticed but offers less pop for an active riding style. Anyone looking for a more playful feedback from the fork will need to speed up the rebound, which also makes it feel less composed. However, the planted character pairs perfectly with a rear suspension that is also tuned for a composed ride feel (e.g., with an X2 or DHX2 shock).
Conclusions: FOX 38 Factory or RockShox ZEB Ultimate?
After countless vertical meters around the globe, one thing is clear: the RockShox ZEB Ultimate wins this showdown on points. It’s the first choice for anyone who regularly wants to adapt their setup to the trail or make on-the-fly adjustments. The clear labeling of the adjusters helps enormously, and the wide, noticeable damping range allows you to tune the fork either very playful or extremely traction-focused depending on your preferences. A real highlight is its lively ride behavior, which encourages active riding without sacrificing confidence.
The FOX 38 Factory, on the other hand, is made for riders who want to dial in their setup once and then simply trust it, with no constant readjustment needed and no second guessing on the trail. It offers an unbeatable planted ride feel that pairs particularly well with powerful shocks like FOX’s X2 or DHX2 models. If you’re looking for maximum composure and value the finest tuning, this is your benchmark. Especially in technical, steep terrain, the FOX shines by riding high in its travel, providing a high level of confidence.
However, it must be clearly stated: both forks operate at an extremely high level, and neither is a bad choice. Ultimately, it comes down to personal preference, riding style, and how well the fork harmonizes with the bike’s rear suspension. One thing is certain: if you’re sitting on the fence between the previous model and the current generation, you should definitely go for the newer model year. Both forks use their travel more eagerly and effectively, and are overall easier to ride than their respective predecessors.
Tops
- Lively, playful ride character of the ZEB
- Intuitive tuning with noticeable click feedback
- High-quality build & labeling of the ZEB adjusters
- FOX 38 offers an unbeatable planted ride feel
- Both forks significantly improved over their predecessors
Flops
- FOX HSC adjuster feels vague & has sharp edges
- FOX rebound range smaller than on the ZEB
- ZEB bottom-out bumper very firm
- FOX air cap difficult to grip
- No separate HSR adjuster on the ZEB
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Words: Reynaldo Ilagan, Peter Walker Photos: Peter Walker
