Exposed length of stanchion on Rockshox Zeb Fork

[Singletrackmind]

Is it normal for a 170mm travel Fork to have only 160-165mm of exposed stanchion after inflation to reach proper sag percentage?

When I lower the psi on my Rockshox Zeb Ultimate to attain ~25% sag and utilize full travel of fork during rides, I do not have the full 170mm of exposed stanchion tubes.

When I inflate the psi so I have 170mm of exposed stanchion, I don't utilize the full travel of my fork during rides even with the high and low speed compressions set wide open.

 

[Greg Watts]

Is it normal for a 170mm travel Fork to have only 160-165mm of exposed stanchion after inflation to reach proper sag percentage? When I lower the psi on my Rockshox Zeb Ultimate to attain ~25% sag and utilize full travel of fork during rides, I do not have the full 170mm of exposed stanchion tubes. ...

@Singletrackmind - completely normal. The 170mm travel figure refers to the internal stroke of the air spring and damper, not the exposed stanchion length. There's always a portion of the stanchion that sits inside the lower legs even at full extension because the fork needs bushing overlap for structural rigidity.

Internally, the seals and bushings were designed to "deliver enough overlap without adding undue drag." Without that overlap your Zeb would flex like a wet noodle.

What you're seeing (160-165mm exposed) is bang on for a 170mm Zeb. Forks typically show the travel amount plus 5-10mm of extra stanchion, and modern longer-travel forks have stanchion measuring only a couple of mm more than the travel they provide.

There's also a small amount of "suckdown" where the air pressure pulls the fork slightly into its travel at rest, eating a few mm of visible stanchion before you even sit on it.

 

[Singletrackmind]

@Singletrackmind - completely normal. The 170mm travel figure refers to the internal stroke of the air spring and damper, not the exposed stanchion length. There's always a portion of the stanchion that sits inside the lower legs even at full extension because the fork needs bushing overlap for structural rigidity.

Internally, the seals and bushings were designed to "deliver enough overlap without adding undue drag." Without that overlap your Zeb would flex like a wet noodle.

What you're seeing (160-165mm exposed) is bang on for a 170mm Zeb. Forks typically show the travel amount plus 5-10mm of extra stanchion, and modern longer-travel forks have stanchion measuring only a couple of mm more than the travel they provide.

There's also a small amount of "suckdown" where the air pressure pulls the fork slightly into its travel at rest, eating a few mm of visible stanchion before you even sit on it.

Thanks for the detailed information. After riding Fox firks for many years, I am running Rockshox Zevs on my Crestline S180 and 2025 Orbea Wild.

Like the plush feel and they seem to ride a little higher in the travel, but perform great.

I am currently running the upper DSD Runt in each fork and will be installing the lower DSD Runt once they arrive.

Will provide feedback with thoughts on improved performance so other riders can benefit from my endeavors.

Seems like the 2027 Rockshox Zeb has incorporated some tangible upgrades from the previous model and am debating if I will give it a go on one of my bikes.

 

[Greg Watts]

Thanks for the detailed information. After riding Fox firks for many years, I am running Rockshox Zevs on my Crestline S180 and 2025 Orbea Wild. Like the plush feel and they seem to ride a little higher in the travel, but perform great. I am currently running the upper DSD Runt in each fork and will...

@Singletrackmind Good timing on that curiosity, because the 2027 Zeb literally just dropped and it's a ground-up redesign. RockShox claims the only part that remains the same is the axle.

The headline changes that should interest you: • LinearXL air spring:

The most significant change is the move to a twin-tube air spring design, chasing a "coil-like" feel with a more linear spring curve. This requires significantly higher air pressures than the previous gen, around 60-80 PSI more, with a new max of 300 PSI.

Given you're already running DSD Runts to get a more linear feel out of your current Zebs, this is essentially RockShox building that philosophy into the fork from the factory.

• Adjustable Bottom Out (ABO): A dial at the bottom of the spring-side leg adjusts the position of the bottom out bumper, letting you tune end-stroke support.

Early testers found most ran it near the 7mm setting, and the bumper can feel abrupt given the linear spring curve, with no softer bumper options available yet.

Worth knowing before you commit. • ButterWagonTech:

Dimples in the stanchions below the wiper seals carry lubricating oil up and over the bushings during compression, leaving a thin film for reduced friction.

Only on the Ultimate tier, mind. • Charger 3.2 damper: