Fox introduces new discipline-specific fork dampers for ‘more confidence and control’ | BikeRadar

Oct 14, 2024

Fox has updated its range of fork dampers, across marathon XC, gravity-based enduro and downhill models.

The Grip X2, Grip X, and Grip SL dampers are designed for gravity, trail and XC riding respectively.

The range aims to help people determine the most suitable fork for their riding type, style, and preference.

Each damper is based on Fox’s Grip system, which uses a self-healing spring-backed IFP architecture, but each is built to meet the needs of the different disciplines.

Fox says its main goal for the dampers, regardless of riding category, was to provide more confidence, control and predictable handling through increased traction.

Fox is celebrating its 50th birthday and this is just the first of new and updated products to be released this year.

Fox claims the Grip X2 is the most advanced and capable gravity damper it has produced.

The Grip X2 features external high and low-speed compression and rebound adjustment for riders to fine-tune their setup.

Fox has also increased internal tunability, especially on the compression damping circuit, providing more control over the damping curve and response.

Fox hopes this will enable riders to use the damping to improve ride performance, comfort and grip.

The Grip X2 has a new 24mm diameter base valve, increased from 20mm on the Grip 2 damper. This enables Fox to spec a larger IFP (internal floating piston).

The larger diameter IFP means the IFP spring could be made shorter and still accommodate the same volume of oil displacement caused by the fork compression.

That shorter IFP design freed up vertical space, enabling Fox engineers to add 23 shims to the base valve compression circuit of the Grip X2, over the seven shims in the GRIP 2. This means compression damping can be more finely tuned to achieve the damping curve Fox believes is best.

The rebound circuits have been designed to minimise cross-talk. This means that when increasing rebound damping, you’re not increasing compression damping concurrently.

Fox aimed to improve quicker damping response to increase predictability from the fork. It says this provides the rider with more confidence.

To accomplish this, Fox balanced the pressure in the system. As the damper compresses, the pressure of the compression damping circuit increases, while the pressure of the rebound damping circuit decreases.

Pressure balancing tunes the mid and base-valve shims to try and keep these pressure changes symmetrical. A 50psi increase in the pressure of the compression circuit would have a corresponding 50psi decrease in the pressure of the rebound circuit.

Fox kept positive pressure in the rebound circuit to stop the oil from dropping below its vapour pressure, so performance-hindering dissolved bubbles can’t form.

Having symmetrical pressure changes means the damper oil behaves the same when transitioning from compression to rebound. It also means there's a minimal lag in the damper's response.

This means damping response kicks in at a claimed 5 to 10ms, providing more predictable control.

Given its gravity-orientated bias, it’s no surprise to see this damper fitted to the unchanged chassis of 36, 38 and 40 forks, covering everything from heavy-duty trail to downhill bikes.

A version of the 34 will also be available with a Grip X2 damper, but this will only be available on complete bikes.

The new Grip X damper blends the best parts from its new Grip X2 and Grip SL damper, according to Fox.

The goal was to save weight, make it easier to set up, and offer usable adjustments on the trail compared to the Grip X2.

The Grip X uses the larger 24mm base valve from Grip X2 to keep as much of the downhill performance as possible, but is designed with different architecture to enable easier on-the-fly adjustment.

The main features of the Grip X are its high-speed compression sweep adjuster and firm mode.

The low-speed compression adjustment is the same needle and orifice design found on the older Grip 2 and Fit 4 dampers. It is adjusted with an indexed dial.

The high-speed compression uses a 170-degree sweep adjuster.

For the first 90 degrees of rotation, high-speed compression is increased by preloading a spring on the shim stack.

As you keep winding the high-speed compression, a cap over the shim stack moves closer to the shim’s outer edges, limiting the shim’s throw and providing a firmer platform.

The last click of adjustment closes the low-speed compression circuit, giving a firm pedalling platform.

Fox claims this design prevents riders from using low-speed compression to shut off the circuit. As soon as you return to your desired high-speed setting, the low-speed compression is where you left it.

In addition, this sweep from around 12 o'clock to 6 o'clock lets you easily return to your preferred high-speed compression setting after using the firm mode without counting clicks.

The Grip X features a single low-speed rebound external adjuster. By removing the high-speed rebound circuit, Fox could use a small mid-valve piston and a smaller piston shaft.

These updates save around 70g over the Grip X2, making it more suitable for its trail-riding audience. It also makes forks easier to set up.

The Grip X damper is available in Fox’s 34, 36, and 38 chassis. The prices for Grip X and Grip X2 equipped forks are the same.

Fox’s major goal for Grip SL was to decrease weight and increase performance relative to its existing lightweight damper, the Fit 4.

Fox says each Grip SL damper is optimised for each fork chassis, ranging from the 40mm travel 32 Taper Cast gravel fork to Fox’s 120mm 34 Step Cast lightweight trail suspension fork.

Fox claims this enables it to shave every gram possible without negatively impacting performance, with an average saving of 60g over the FIT 4 in its 100mm travel option.

Fox has removed externally adjustable low-speed compression damping to help accomplish this.

Grip SL instead features a three-position adjuster. This is claimed to provide riders with all the options they desire.

It's also available in a remote lockout option.

As with the Grip X2 and Grip X dampers, Fox uses spring-backed IFP, unlike the bladder system found in FIT 4.

Fox uses this, plus the base and mid-valve damping relationship, to provide constant, but low positive pressure in the damper.

This pressure-balancing claims to improve damping performance and quicker damping response times.

The base valve also uses a wider diameter piston. This provides more space for shims in the damper, offering better compression-damping tunability.

The three-position adjuster offers open, medium, and firm modes.

The open mode provides maximum travel with balanced damping and quick responsive circuits for heightened grip and predictability.

The medium position introduces the floating shim stack of the base valve. That helps provide bump and rider support for aggressively attacking trails. It is most suitable for rolling, flatter terrain.

The damper's firm mode fully engages the floating valve stack. The lockout is rigid for hammering the pedals, but also provides a smooth blow-off to prevent damage to the fork or loss of control.

The Fit 4 damper was widely known to be difficult to adjust while riding. Fox says it has addressed this and the new dial is easily turned whether the fork is weighted or unweighted.

The Grip SL damper is available in Fox 32 Taper Cast, 32 Step Cast, and 34 Stap Cast forks.

The new dampers will be rolling out in Fox’s 2025 model forks.

Except for the new Fox 32 Step Cast forks, the chassis of the 34 Step Cast, 34, 36, 38, and 40 forks remain unchanged.

That means these new dampers can be bought aftermarket and are backwards compatible with existing fork models.

The 2025 forks will have black and orange colourways, and there are limited edition gold models – 1,974, to be exact.

The new forks feature updated lower-friction bushings.

Prices are to be confirmed.