We spotted an unreleased single-crown enduro fork at La Thuile's enduro Mountain Bike World Cup (EDR) in Italy.
The fork was fitted to 2025 series winner (yep, she's wrapped up the overall title chase with one EDR to go) Ella Conolly's yet-to-be-released Cannondale enduro bike, and we managed to get some spy shots ahead of the fourth nighttime stage.
The new fork clearly uses the same 38mm-diameter stanchions as the current-generation RockShox ZEB – which was released in 2023 – which leads me to think it will replace the current ZEB when it's ready to be launched.
When will that be? Well, it's fair to assume that if World Cup racers are riding it, it's going to be close to production – those guys wouldn't risk riding prototype kit if it wasn't able to perform at the highest level.
What's new?
The two biggest things that stand out are the arch – which joins the two lower legs – and the bottom rear of the left-hand lower leg.
Stiffness tuning?
Starting with the crown, this has a black-coloured, presumably plastic, cover on it.
It's hard to determine the functionality of this, but it could be used for two things – either independently or simultaneously.
Firstly, it could be a stiffness tuner. The black section is merely a plastic cover that hides removable metal bars of varying thicknesses that are bolted to either side of the arch, used to tune how stiff the fork feels.
The thicker these metal bars are, the stiffer the fork is. The thinner they are, the more flex it has. This would be great for harder or lighter riders, who could tune the fork to their preferences.
Alternatively, the supports or stiffness tuners could be attached directly to the black moulding, and you'd swap the entire thing out to alter how the fork feels.
Electronic wizardry
Alternatively, it could be a shroud for additional Flight Attendant sensors.
Conolly's bike is fitted with the Flight Attendant Charger damper in the right-hand leg, which uses electronics to alter the damper's settings according to the terrain you're riding.
Maybe RockShox is looking at additional ways to incorporate higher sensor-data resolution to fine-tune its on-the-fly electronic adjustments and this is the best place to fit those extra bits of electronics.
Re-tuned air spring
Zip-tied to the bottom of the left-hand lower leg is another cover, but this one looks way less integral and refined than the arch's.
The shroud, as it is maybe best referred to, looks to be 3D-printed and designed to cover or hide something on the lower leg.
Traditionally, the left-hand side of RockShox forks is reserved for the air spring, and this unreleased prototype doesn't appear to deviate from that theme.
Therefore, behind the shroud may be a bump, bulge or attachment to the fork's foot nut, used to create a higher-volume negative air spring.
There's an aftermarket product that does exactly this for the ZEB, called the Vorsprung Suspension Secus.
This attaches to the bottom of the fork and increases the negative spring's volume, creating improved sensitivity at the start of its stroke and giving it a linear spring rate with less ramp-up.
For those who struggle to get full travel on their ZEB forks, or make them sensitive enough, this upgrade can potentially solve those issues.
RockShox may be trying to achieve the same thing straight out of the box with this new prototype fork.
Even more electronics?
We can't see what is going on behind the cover and it's covering the brake caliper slightly.
It's not inconceivable that there are even more electronics hiding behind it, that are hooked up to the Maven brake and connected to the Flight Attendant system.
They could simply measure whether the brake is on or off, or even brake forces, to tell Flight Attendant to open and close the damper accordingly.
Maybe RockShox has found a way to stop fork dive with electronics, potentially helping to stabilise a bike's geometry where it's most needed.
Trust's Message linkage fork tried to do this, but the brand's innovative take on suspension didn't take off and it went out of business.
Maybe RockShox's more conventional approach will fare better.
Even more changes, but they're less obvious
These extra changes are subtle, but probably just as important.
Compared to the current-generation ZEB, the lower-leg arch moulding, where it joins each leg, is way more chiselled and shaped.
This has to be related to the black moulding on the arch, but it's interesting to see this prototype with such angular shapes.
RockShox could be on a drive to shave weight from the fork while retaining strength. The cutouts shave grams, while the frame-like struts retain the same strength as before.
The crown and axle don't appear significantly different from the current-generation fork (tapered and 15x110mm), but it's hard to say whether or not there are any internal changes.
How close is this fork to production?
Again, this is a tricky question to answer, but the fork looks less a prototype and closer to being production-ready.
If the timeline of Fox's Podium fork is anything to go by, the first sightings of an inverted RAD prototype fork were in early April at Sea Otter, and the official launch followed on 24 June.
By that logic, we may expect the new RockShox fork to launch in late October.
We've contacted RockShox for comment, but at the time of publishing it hasn't replied. Once we get more information, we'll update this article.
