Suspension Fork Shootout: Fox 38 Vs. RockShox ZEB Forks

Fox 38Vs.RockShox ZEB

    

Last year Fox debuted the 38, a single-crown air fork built for bike-park laps, free riders and enduro racers looking for tougher performance. As many of you know, RockShox is another popular brand of mountain bike suspension, so, of course, RockShox has launched its own iteration to compete with Fox. RockShox has named its new fork the ZEB. Just as the 38 sits in between the 36 and 40, the ZEB lands in the middle of the Lyrik and the dual-crown Boxxer.

ZEB utilizes Charger technology. Depending on the version purchased, the damper will vary from model to model. The Ultimate and Select+ use a Charger 2.1 RC2 damper with independent high- and low-speed compression with rebound adjustment. The less-adjustable ZEB Select uses a Charger RC while the entry-level ZEB uses a Charger R damper.

 

Like most RockShox products the ZEB fork includes sag percentage gradients and a sag o-ring. The ZEB’s new lower leg arch is designed to ensure plenty of clearance for burlier headtube profiles and has mounts for an integrated fender.

 

WHAT ARE THE DIFFERENCES?

RockShox and Fox have nearly identical goals for their latest forks. Both are designed and engineered to meet the challenges of Enduro World Series tracks. Racers are always pushing for faster bikes, so it was only a matter of time before they would require suspension that could keep up. The Fox 38 and ZEB both feature 38mm stanchions. Essentially, a stiffer fork creates less deviation when pushing through a trail, along with less binding resistance. Just like the Fox 38 sitting in between the 36 and 40, the RockShox ZEB bridges the gap between the 37mm Lyrik and the 35mm dual-crown Boxxer.

RockShox claims that the ZEB is 21.5-percent stiffer torsionally than the Lyrik. Here are the tech numbers: The ZEB is 7-percent stiffer when it comes to side bends and 2-percent stiffer in fore and aft bending. In comparison, Fox claims the 38 is 17-percent stiffer fore and aft and 38-percent stiffer under torsional loads than its smaller-stanchioned family member, the Fox 36.

Diving in, the first big difference in our face-off is pricing. The top-level Fox Factory Series 38 hits the pocket book at $1199, while the highest-tier RockShox ZEB Ultimate retails for $999. That $200 difference could determine a rider’s decision.

There are five different models that RockShox is offering with the ZEB. The top tier is the ZEB Ultimate equipped with a Charger 2.1 RC2 damper and the new DebonAir spring. This damper features independent HSC (high-speed compression) and LSC (low-speed compression), with HSC having five clicks and LSC having 16 but only one single rebound adjustment with 16 clicks. Next in the line is the ZEB Select+. This is an option that will only be available on complete bikes such as the Salsa Cassidy we tested last month. It, too, uses the Charger 2.1 damper but doesn’t offer the HSC adjustment.

From there, we land on the ZEB Select. This version is just like the Select+ we tested, but has an adjustable low-speed compression and rebound through the equipped Charger RC damper. The lowest-priced model, simply called the ZEB, is the entry-level version where the only adjustments are air pressure and rebound. It’s very simple and straightforward for any user and only costs $700.

Fox’s updates put the price in the range of $949–$1199, depending on the GRIP damper and stanchion coating. The Fox 38 is currently available in Factory, Performance Elite, Performance and e-bike-specific models with GRIP2 and GRIP dampers. The Factory Series 38 with the GRIP2 damper has a large degree of adjustability. There are 22 clicks of HSC and LSC, as well as stand-alone HSR and LSR knobs, with the HSR having eight clicks and LSR having 22. For the average rider, the ZEB RC2 may prove to be a bit easier to set up, but it is not quite as tunable as the Fox GRIP2. More on this coming up!

Another difference is the travel and offset options. Like the 38, the ZEB is available in 27.5- or 29-inch models. Unlike the 38 that tops off at 180mm, RockShox has stepped it up—the ZEB is available with 190mm of travel. In the offset department, Fox offers 27.5 inches with either a 44mm or 37mm offset and 29 inches with 51mm and 44mm offsets. RockShox took a different approach with the 27-inch having options for either 38mm or 44mm, while the 29-inch is only available in 44mm.

When comparing features, we cannot overlook the external features on the Fox. The 38 uses air bleeders designed to help release pressure built up in the lowers when air is accumulated during riding. This can be helpful when you are rapidly changing elevation. It’s a clever design; however, these bleeders are not a feature you will find on the RockShox ZEB. Furthermore, both brands take a distinct approach to their axles. RockShox uses a 15mm axle, but you have the option to use the TorqueCaps that are utilized on all the latest RockShox forks. This simple hub-cap upgrade increases the surface area to 27mm. The TorqueCaps are used to create a larger surface area upon contact while improving stiffness and steering.

As the caps are a RockShox-only feature, Fox has its very own creation with the floating axle design. To be brief, the floating axle allows you to tighten down the wheel in the fork without binding the two lower legs together. The engineers at Fox felt there was too much potential for binding or friction to occur with the movement of the fork. This design solves the problem by allowing the fork legs to remain parallel, with a wheel properly mounted and ready to roll.

The rebound adjustment is dependent on the air pressure setting. For example, higher air pressures require more rebound damping. The FOX 38 Factory Series is equipped with a fine-tuned high and low-speed rebound knob.

 

GETTING THINGS DIALED

Don’t underestimate the importance of proper suspension setup. Some riders like to set it and forget about it, while some like to look at full data charts to hone in on the best setting for their riding style. If you’re the data-crunching type, the tunability of the Fox 38 is for you. For a bit easier setup, the ZEB takes the crown. Fox’s handy guide gives you a great starting point to dial in your fork. To achieve proper sag, we ended up adding 5 psi over what was recommended on Fox’s weight chart. During our testing, we messed with HSC and LSC, but eventually found a spot that lined up with our trail conditions.

We liked the fork to respond a bit quicker than it did with the initial suggestions from Fox, so we also adjusted the rebound settings on the trail. For the ZEB, we used RockShox’s Trailhead app on our smartphones to find our recommended settings. As with the 38, we went a couple of clicks faster on rebound in the parking-lot tests; however, unlike with the back-and-forth tuning on the 38, we did not have to fuss with air pressure or rebound after that with the RockShox Zeb.

The new FOX 38 is available in Factory, Performance Elite, Performance, and E-Bike models with GRIP2 and GRIP dampers.

 

At the back of the fork legs there are bleeder valves to help remove air from inside the fork legs. Running up and down from the bleeders are air/oil channels that increase air volume and help with oil flow. These channels give the fork a little bit more air volume as the air flow passes the bushings into the area above.

 

ON THE TRAIL

Things get tricky from this point forward for this Fox-versus-RockShox face-off. It is very difficult to choose a winner when both options feel great on the track. As we hinted at it in the previous Fox 38 article in our November 2020 issue, these more robust siblings launched by the big suspension brands are not necessarily for everyone. Any way you slice it, most of us are not going to be pushing the limits like Richie Rude coming in for a podium win. With that said, it can be argued that these forks are best for riders in the 200-pound range or the hard trail ripper who wants all the downhill power he can get.

The added stiffness is no doubt noticeable on the trail. At the same time, the added stiffness requires the rider to be more prepared to work with the fork responding to the trail. Keep in mind that both RockShox and Fox still offer the Lyrik and 36. These less-robust versions are great for riders whose styles may not benefit from the beefed-up stiffness and who are interested in saving some weight at the front.

The 38 seems to soak up huck-to-flat hits with slightly more grace than the ZEB. With that said, both handle back-to-back hits well. The ZEB feels similar to the Lyrik, but the ZEB feels a touch softer through high-speed bumps. Both the 38 and ZEB are noticeably stiffer than a 36 or Lyrik. We immediately noticed how these beefier constructions responded on steep, sharp turns where most of the rider’s weight is directly shifted forward over the bike. We also appreciated the stiffness through chunky straights. In these sections, letting go of the brakes and stomping forward is the best method. Overall, there is not much difference in terms of performance and reliability between the ZEB and 38. Both handle rough terrain remarkably well and have excellent control due to less flex.

The launches of the RockShox ZEB and Fox 38 have created a new suspension-fork category perfect for long-travel enduro rigs that go down the gnarliest sections riders can conquer. Since the differences between the ZEB and 38 are subtle, the deciding factor for most will be price. We mainly tested the ZEB Select+ ($800) up against the Fox 38 Performance Series ($950), but have lots of ride time on the highest-end Fox 38 Factory Series option ($1199). If you are looking for increased performance while getting the most bang for your buck, look into a ZEB. As for the MBA wrecking crew, the Fox 38 wins our affection, despite the extra cash, because of its adjustability and features. 

www.sram.com

www.ridefox.com


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