Sunday, December 22, 2024

Head to Head Review: 2025 RockShox Zeb vs Fox 38 – Pinkbike

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This isn’t the first time we’ve pitted the RockShox Zeb against the Fox 38, and it certainly won’t be the last. Both companies continue to battle for dominance, rolling out small and not-so-small revisions each season in the quest for that top spot. That doesn’t meant there aren’t other worthy competitors out there, but for the sake of this matchup we focused on the two brands you’re most likely to see spec’d on a new mountain bike this year.

Testing involved multiple days of back-to-back testing in the Whistler Bike Park (I know, sounds tough), along with multiple other rides in Squamish, BC, and Bellingham, Washington.

RockShox Zeb Ultimate Details

• 38mm stanchions
• Damper: Charger 3.1 RC2 w/ ButterCups
• Air spring: DebonAir+ w/ ButterCups
• Wheel size: 27.5″, 29″
• Travel options: 150, 160, 170, 180, 190mm
• Actual weight: 2324 grams (29″, 170mm travel w/ 190mm steerer + starnut)
• Price: $1,159
• www.rockshox.com

Fox 38 Factory Details

• 38mm stanchions
• Damper: Grip X2
• Air spring: Float EVOL
• Wheel size: 27.5″, 29″
• Travel options: 160, 170, 180mm
• Weight: 2381 grams (29″, 170mm travel w/ 190mm steerer + starnut)
• Price: $1,249 USD
• www.ridefox.com

Weight & Price

Cold hard facts are the easiest to compare – there’s no trying to put sensations into words, no trying to figure out a better adjective for ‘squishy.’ When it comes to price, both forks are over $1,000, but the 38 is $90 more than the Zeb, at $1,249 vs $1,159 USD.

The weight is close enough that I’d call it a draw. The Zeb is a little lighter, especially when you factor in the brake adaptor you’ll need to run a 200mm rotor on the 38, but at the end of the day the number of grams shouldn’t be a deciding factor in this category – both forks were designed with more of a focus on strength and performance rather than saving grams.

Bleed Valves

Both the 38 and Zeb have bleed valves that are designed to release any unwanted air pressure that’s built up in the lowers. The 38 uses a push button design, and the Zeb uses a threaded bolt that can be backed off slightly to release the trapped air.

That threaded bolt design is likely the result of Fox suing RockShox, but it actually has an unforeseen benefit – on Whistler’s new Fitzimmons chairlift the rack can contact the bleed valves of a fork, letting a snail trail of oil leak out on the way up. That can’t happen with the Zeb, thanks to the forced revision.

Fox 38 Features and Updates

For 2025, Fox revised their Grip2 damper, splitting it into the Grip X2 version reviewed here, and the Grip X, which is aimed more at trail and all-mountain bikes.

The Grip X2 damper has a larger base valve to allow for more oil flow, along with a new stack of 23 shims (Grip 2 had 7 shims) that allows for a much greater range of tuning options. There’s also a two-stepped ‘hat’ that’s used to determine the high speed compression’s adjustment range, and it can be swapped out to suit a rider’s needs.

The 38’s bushing design has also been changed. Previously, there were vertical grooves in the bushings that were supposed to help with oil flow, but it turned out those grooves increased the amount of friction, so they were removed, and the bushings now have a consistent surface.

RockShox Zeb Features and Updates

The changes to the Zeb’s damper design weren’t quite as extensive as the changes to the 38, but they also involved increasing the amount of oil flowing through the damping circuit. According to RockShox, there’s now 68% more oil flow through the low-speed circuit, which means lighter riders or rider who prefer less low speed compression have more useable options.

Along with the increased oil flow, the new damper has an larger high speed compression pyramid. That increased size allows for more restriction of oil flow when the high speed compression is fully closed, which increases the amount of damping.

RockShox also updated their bushing production process and implemented it on the 2025 Zeb, Lyrik, and Pike forks. The changes to the manufacturing process were intended to improve the consistency, and to ensure that there’s a little bushing friction as possible on all models.

Testing Basics

The basics of the Zeb and the 38 seem to be getting increasingly similar, so we headed to the Whistler Bike Park to do multiple rounds of back-to-back testing in order to see how all of the recent changes felt in the real world.

Our main test track was Upper and Lower Whistler DH, which has a good mix of higher speed, rough sections mixed with slightly slower, steeper portions that require heavy braking. It’s a track that wouldn’t be out of place in an enduro race, and the higher speeds and repeated hard impacts make it ideal for fork testing.

In order to keep things as consistent as possible, both forks were set up with a similar amount of sag, and enough volume spacers so that a similar amount of travel was used by the end of each run. Once we’d set each fork up to our liking it was time to start doing back-to-back laps to really figure out the similarities and differences.

Setup

When it comes to setup, Henry and I sit on different sides of the fence. My setup for both forks is close to the manufacturers’ recommended settings, and if it does deviate it ends up being towards the lighter side of low and high speed compression damping.

Henry has fallen into a data acquisition rabbit hole lately, and tends to run his high speed compression fully closed, low speed compression close to closed, and rebound set very fast, with a higher amount of sag. It’s certainly not a setup that I would run, but it’s working for him, so I try not to argue, at least not too much.

The good thing is that we were both able to find setups that felt comfortable and worked with our riding styles, which really is the main goal, and it’s a testament to the range of possibilities that both forks possess.

On The Trail

When it comes to the initial stroke, the Zeb feels more eager to break into its travel, with a more fluttery feel compared to the 38. That leads to an overall sensation that’s more muted than the 38 – the Zeb seems to round off the edges of the impacts before they reach your hands to a greater extent than the 38 does. Now, I should stress that neither fork felt harsh, and I didn’t experience any unexpected hand / forearm issues even after smashing out laps for multiple days in a row, but for riders who prefer a plusher, almost coil-like fork, the Zeb gets the point here.

To parse it out a little further, the Zeb feels like it prioritizes comfort a bit more than precision. It’s very eager to break into its travel, and also to use that initial portion of its travel. ‘Busier’ is the term that came to mind when trying to compare the Zeb and the 38 – the 38 has a more immediate, direct feel that lets you know exactly what your front wheel is doing. Henry’s analogy was that that that Zeb sucked itself to the ground, and the 38 drove itself into the ground, which I think is fitting.

Both Henry and I were able to get the rebound speeds as fast as we wanted with both forks, something that riders had found lacking in the previous Zeb. Interestingly, the rebound circuit of the new Zeb is the same as before, which means it may be the increased oil flow and compression shim stack, or possible the better bushing tolerances that are allowing for that faster return speed.

Bottom out resistance can easily be altered by adding or subtracting volume spacers, and I was happy running one spacer in each fork. That setup gave me plenty of travel to work with, with a little extra in reserve for those unexpected big hits.

Is there an ideal rider for either fork? If pressed, I’d say that the 38 feels ‘racier,’ and not in a skimpy outfit kind of way. That aforementioned direct feel makes it seem as if it wants to deal with an impact as quickly as possible and keep charging forward, exactly what you want when you’re trying to be the first to the finish line. Of course, the Zeb can certainly be raced, and it already has plenty of podium finishes to its name, but I’d say the ideal candidate for the Zeb is someone who places grip and comfort higher on their priority list, and doesn’t mind a slightly more active feeling front end.

Durability

Neither fork developed any issues during our testing, and they both saw plenty of use in wet, muddy conditions, along with drier, almost dusty laps. There hasn’t been any unwanted bushing play, creaky crowns, or seal issues to speak of. I’d call this portion a draw – the basics are taken care of, and both forks can withstand harsh conditions without any trouble. We’ll update this if any anything develops, but so far there hasn’t been any reason for concern.


Verdict

At the end of the day, the 2025 RockShox Zeb and the Fox 38 fork are both excellent forks. They offer a good range of usable adjustments, and are both quiet and consistent out on the trail. However, we’re not going to call this fork-off a draw. Henry and I came to our own conclusions independently, and when it was time to reveal the fork we preferred the answer was the same – the Fox 38. That doesn’t mean the Zeb is an inferior product – far from it – but the controlled support that the 38 delivers earned it our votes, and the win in this competition.

But wait, there’s more. If you can’t stand videos, and don’t want to read all those pesky words, how about listening to a podcast instead? In this episode, Henry and I dig a little further into how we tested, our setup preferences, and then play school teacher to give each fork a grade.

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