Shock Showdown: Bilstein 8112 vs Fox, King, SDI, and Icon

Bilstein 8112s Versus the World

Bilstein 8112s usually rank as our absolute favorite coilover option across nearly every vehicle we’ve tested them on—but that doesn’t mean they’re without competition. While the newer Zone Control shocks have taken the industry by storm, the big three—Fox, King, and Icon—haven’t been sitting still either.

Now that we’ve logged seat time with all of these options on similar applications, we’re in a rare position to directly compare them. That’s exactly what we’re here to do.

Bilstein 8112 / 8100 Zone Control

Most of you are probably familiar with the 8112 and 8100 Zone Control systems, but for those who aren’t, here’s the quick breakdown:

They use a 2.6” body design with internal hydraulic bump stops on both compression and rebound. These bump stops exponentially increase damping force at the ends of the stroke, making them position-sensitive—like many of the other shocks on this list.

Where they differ is how they achieve that control. Instead of bleeding off damping in the primary ride zone (like some competitors), they add damping force outside of it. The result? More support than their body size might suggest.

• Compression (Jounce Cut-Off): Two-stage system → three ride zones
• Rebound (Rebound Cut-Off): Single-stage system → two ride zones

Select models also offer DSA+ (Dual-Speed Adjusters), which provide:

• One of the widest adjustment ranges on the market
• Independent control over compression
• Adjustable JCO for dialing in bottom-out resistance

There have been complaints about these shocks feeling a bit clunky or noisy, but in our experience, when properly set up, they feel seamless. The small amount of feedback they do provide is often actually welcome.

Shop Bilstein 8112 / 8100

Fox Factory Race Series IBP

When Fox names something “Factory Race Series,” they usually mean it—and these shocks bring legitimate race-derived tech to bolt-on applications.

Their internal bypass (IBP) design mimics an external bypass shock using a sleeve with precision-drilled ports inside the shock body. Oil bypasses the main piston through these ports until the shock nears the end of its travel. At that point, flow is forced through the main piston valving, dramatically increasing damping force.

Each port can be shimmed individually, allowing for extremely precise tuning across multiple ride zones.

The Upside:

• Exceptionally smooth and quiet operation
• Potentially more ride zones than other designs
• Highly tunable

The tradeoff:

This is effectively a twin-tube design, which reduces piston size:

• 3.0 shocks use 2.5 pistons
• 2.5 shocks use 2.0 pistons

This tradeoff limits total damping force. So while you gain refinement and smoothness, you give up some big-bump support.

Shop Fox Factory Race Series IBP

King Internal Bypass (IBP)

King’s IBP shocks may very well be the original internally contained, position-sensitive design in the off-road space.

Their approach uses a secondary piston that engages at the end of the compression stroke, adding progressive damping. This secondary piston is fully tunable, just like the main piston, allowing for precise control over that final zone.

The challenge:

Because the secondary piston only engages on compression, there’s no equivalent support on rebound. To compensate, setups often require:

• Heavier rebound damping
• More “packing”

That can reduce overall responsiveness and lead to harsher top-outs when running a single shock.

Where they shine:

• Simpler design → easier to tune and revalve
• Excellent pairing with external bypass shocks
• Strong option for high-end, multi-shock setups

Shop King Internal Bypass

Icon CDEV / SDI E-Clik

Electronically controlled shocks are the future and Icon Vehicle Dynamics is fully leaning into it.

The easiest way to describe these systems:

It’s like having a traditional adjustable shock with a tiny wizard constantly turning the knobs for you in real time.

These systems continuously adjust damping based on terrain and driving style by monitoring:

• G-force data
• Shock flow data
• Vehicle telemetry (especially in SDI systems)

And the best part? No more getting out of the truck to make suspension adjustments.

To add some position sensitivity, Icon places the reservoir port near the end of the shock body to create a mild progressive zone. Still, they lag slightly behind true position-sensitive designs in small bump compliance and maximum big-bump support.

But here’s what you get with the tradeoff:

• Far better handling
• Excellent performance under load
• Adaptive behavior across changing conditions

Comparison: Which One Wins?

Despite wildly different designs, this race is much closer than it seems. Each option excels in a specific area, and as always, the “best” choice depends entirely on your needs.

Why We Lean Toward Bilstein

For our use case, the Bilstein 8112 checks the most boxes:

• Outstanding support and control (even rivaling some 3.0s)
• Solid comfort
• DSA+ adjustability pushes performance even further

But just because they’re our favorite doesn’t mean they’re the right choice for everyone.

Where Fox Stands Out

Fox IBP shocks arguably offer:

• The smoothest ride
• The quietest operation
• The most refined feel

Their multiple ride zones and lack of internal “contact events” (like bump stop engagement) make them incredibly plush.

The downside?

They can take more time (and more tuning attempts) to truly dial in. But when you get there, the payoff is huge.

Where King Excels

• The easiest to tune and rework
• Less complex internally
• Highly adaptable

They also pair exceptionally well with external bypass shocks, making them a top choice for more advanced builds.

Where Icon Takes the Lead

Position-sensitive shocks are great—until your vehicle load changes. That’s where electronic systems like Icon’s CDEV and SDI E-Clik shine:

• Minimal sway
• Consistent handling regardless of load
• No harsh penalties for sitting outside the ideal ride zone

If you tow, haul, or frequently change your setup, these systems are hard to beat. The SDI load-adjustment feature alone can feel like magic.

The Real “Best of the Best”

The ultimate setups combine position sensitivity with electronic control. If you’re chasing maximum performance, these next options deserve serious attention.

Fox 3.2 Live Valve

Fox’s newer 3.2 Live Valve systems (available on Raptors, Broncos, Tacomas, Tundras, and 4Runners) combine:

• 3.0 internal bypass architecture
• Real-time electronic adjustment

We haven’t tested them yet, but expectations are high:

• Improved small bump compliance
• Better big-bump control
• Significantly enhanced handling

Icon 3.0 CDEV

This is where things get especially interesting.

Icon essentially took the concept we’ve all been thinking about... pairing position-sensitive shocks with electronic control... and brought it to market.

The 3.0 CDEV system is functionally similar to an 8112-style design, but with:

• Larger 3.0 body and piston
• More overall damping capacity
• Available external bypass CDEV options

Currently applications are limited to Tundras and Gen 3 Raptors, but they are likely expanding their offerings soon.

Our take:

Fox 3.2s may edge them out in smoothness and noise, but in terms of raw performance potential, it’s hard to imagine anything clearly surpassing the Icon 3.0 CDEV right now.

Icon has taken its fair share of criticism over the years but with products like this, it’s safe to say the competition is paying attention.

Final Thoughts

There’s no universal winner here, only the best choice for your specific goals.

• Want maximum support and tunability? Bilstein
• Want the smoothest, most refined ride? Fox
• Want simplicity and tuning flexibility? King
• Want adaptability and real-world versatility? Icon

And if you want it all? Start looking at electronically controlled, position-sensitive hybrids. That’s where things are heading fast.