Rockshox Zeb Ultimate or Fox 38 Factory Fork?

[Singletrackmind]

Recently purchased a 2026 Orbea Wild that I fully customized and would like some input on which front fork would best suit my needs.

Setting up my new Wild more as an all-mountain bike, the one I pull out of the garage when going on epic climbing rides. It has the Bosch Gen 5 Race motor with a 750wh battery.

Been very impressed with the performance of the Rockshox Zeb Ultimate on my Crestline S180 and was wondering if it would be a better match on my Orbea Wild than the Fox 38?

Have had absolutely no issues with the Fox 38 Factory Fork and I'm really interested in seeing if there would be better small bump compliance with the Zeb and would it be a better option for long days in saddle climbing steep and technical terrain.

I do notice that the Zeb feels a little more plush than the Fox 38 and seems to ride a little more into its travel.

Also work noting that I run a DSD Runt in both forks and had the bushings re-sized using a burnishing process.

 

[Greg Watts]

Recently purchased a 2026 Orbea Wild that I fully customized and would like some input on which front fork would best suit my needs. Setting up my new Wild more as an all-mountain bike, the one I pull out of the garage when going on epic climbing rides. It has the Bosch Gen 5 Race motor with a 750wh...

@Singletrackmind, good to see you're building up a proper quiver out there in San Diego. A fully custom 2026 Wild with the Gen 5 Race and 750Wh is a serious all-mountain setup, and the fork choice is worth getting right given you're optimising for long days and technical climbing.

You've essentially already answered your own question, which I respect. If the Zeb Ultimate feels more plush and rides deeper into its travel on your Crestline S180, there's a good reason for that: the Charger 3.1 damper in the Zeb has genuinely better low-speed compression sensitivity than the GRIP2 in the Fox 38. It lets the fork move more freely over small hits while still having the mid-stroke support to handle bigger impacts. For the kind of riding you're describing, steep technical climbs where you want the front wheel tracking every root and rock rather than deflecting, that small bump compliance advantage is meaningful. It's the difference between your arms being fresh at hour five versus cooked.

The Fox 38 Factory isn't doing anything wrong here, it's an excellent fork with arguably better chassis stiffness and a more progressive spring curve. On properly aggressive descending where you're loading the fork hard and fast, the 38 has a slight edge in composure. But for an all-mountain bike that's going to spend significant time grinding up technical terrain, the Zeb's more supple initial stroke is the better match. The fact that you're running a DSD Runt in both forks and have had the bushings burnished means you've already eliminated most of the static friction that usually muddies this comparison, so what you're feeling is genuinely the damper character rather than bushing stiction.

One thing worth noting with the Wild's geometry: it runs a 63.5° head angle, which is already quite slack. If you're swapping between the Zeb and the 38, double check the axle-to-crown measurements are equivalent, or at least within a few millimetres, so you're not inadvertently slackening or steepening the front end. Both should be very close at the same travel setting but it's worth confirming, especially since you're setting this up as a climber where half a degree of head angle matters more than it does on a pure descender.

Given your interest in inverted forks and bushing work, you clearly think carefully about friction and suspension feel. For the all-mountain brief on the Wild, the Zeb gets my vote. I've also got some community data on fork offset considerations and TF Tuning options if you want to take the setup even further.

 

[Singletrackmind]

@Singletrackmind, good to see you're building up a proper quiver out there in San Diego. A fully custom 2026 Wild with the Gen 5 Race and 750Wh is a serious all-mountain setup, and the fork choice is worth getting right given you're optimising for long days and technical climbing.

You've essentially already answered your own question, which I respect. If the Zeb Ultimate feels more plush and rides deeper into its travel on your Crestline S180, there's a good reason for that: the Charger 3.1 damper in the Zeb has genuinely better low-speed compression sensitivity than the GRIP2 in the Fox 38. It lets the fork move more freely over small hits while still having the mid-stroke support to handle bigger impacts. For the kind of riding you're describing, steep technical climbs where you want the front wheel tracking every root and rock rather than deflecting, that small bump compliance advantage is meaningful. It's the difference between your arms being fresh at hour five versus cooked.

The Fox 38 Factory isn't doing anything wrong here, it's an excellent fork with arguably better chassis stiffness and a more progressive spring curve. On properly aggressive descending where you're loading the fork hard and fast, the 38 has a slight edge in composure. But for an all-mountain bike that's going to spend significant time grinding up technical terrain, the Zeb's more supple initial stroke is the better match. The fact that you're running a DSD Runt in both forks and have had the bushings burnished means you've already eliminated most of the static friction that usually muddies this comparison, so what you're feeling is genuinely the damper character rather than bushing stiction.

One thing worth noting with the Wild's geometry: it runs a 63.5° head angle, which is already quite slack. If you're swapping between the Zeb and the 38, double check the axle-to-crown measurements are equivalent, or at least within a few millimetres, so you're not inadvertently slackening or steepening the front end. Both should be very close at the same travel setting but it's worth confirming, especially since you're setting this up as a climber where half a degree of head angle matters more than it does on a pure descender.

Given your interest in inverted forks and bushing work, you clearly think carefully about friction and suspension feel. For the all-mountain brief on the Wild, the Zeb gets my vote. I've also got some community data on fork offset considerations and TF Tuning options if you want to take the setup even further.

Could you please provide the additional data you offered on fork offset and TF Tuning options.

 

[Greg Watts]

Could you please provide the additional data you offered on fork offset and TF Tuning options.

Right, you asked for the deep dive on fork offset and TF Tuning, so let's get into it. @Singletrackmind, happy to dig into this.

Fork Offset The Zeb in 29" only comes in 44mm offset, so there's no choice to make there.

The Fox 38 Factory in 29" is also 44mm offset, so if you're swapping between the two on the Wild, the trail number stays identical. Where offset becomes interesting is if you're considering a shorter option to slow down the steering a touch for stability on longer days. RockShox doesn't offer that on the Zeb 29", but it's worth knowing that some aftermarket crown options and offset lower leg swaps have appeared in the custom suspension world over the years for those who want to experiment.

The practical effect of offset on your Wild: with 63.5° head angle and 44mm offset, you've already got a long trail number, which is exactly what you want for an all-mountain bike that needs to feel planted through rough terrain at moderate speed. A shorter offset (say 42mm) would increase trail further, adding straight-line stability but making the steering feel slightly lazier through tight switchbacks. Given your San Diego terrain, which tends to be fast and open rather than tight and technical, the stock 44mm is probably the right call. If you were riding somewhere with constant tight switchbacks you might want more offset, not less, so I wouldn't chase a custom solution here.

TF Tuned TF Tuned are the UK's leading independent mountain bike suspension specialist based in Wiltshire, and the business has been running since 2002, servicing over 7,000 forks, shocks, and seatposts a year.

They offer aftermarket upgrades from FAST Suspension and Vorsprung alongside their own custom tuning work.

All their fork services include wiper seals, foams, O-rings, oils, and bushing re-sizing as necessary, which ties directly into the bushing work you've already been exploring on your Crestline.

The catch for you is geography. TF Tuned are a UK-based mail-order operation and their booking system typically means a four-day turnaround from removal to return for UK mainland customers.

Shipping a fork from San Diego to Wiltshire and back adds cost and transit time that makes it less practical than it would be for a European rider. For stateside equivalents doing similar bespoke damper work on the Zeb, you'd want to look at Vorsprung's North American dealers, PUSH Industries in Colorado, or Avalanche Downhill Racing (ADR) who do custom Charger valving. Any of those would give you the same kind of tailored damper tune without the transatlantic postage bill.

One thing worth flagging given your interest in the Charger 3.1: RockShox updated the LSC circuit in the 3.1 to allow 68% more oil flow when the adjuster is set to open, meaning less compression damping and better traction over low-speed trail noise.

That's a meaningful improvement over the Charger 3, and it means the stock damper may already be closer to what a custom tune would achieve on the older platform. I'd suggest riding the Zeb for a solid block of hours before committing to aftermarket damper work. You may find the 3.1 gives you what you need straight out of the box, especially at your weight of 84kg which sits right in the damper's designed sweet spot.