Fanatec CSL pedal 2-Stage Clutch mod

3D printable, Low-hardware mod to adapt a standard Fanatec CSL pedal (Old brake pedal when using Loadcell kit) to a true, 2-stage Clutch pedal with simulated bite-point. Other mods I had tried just did not generate the true bite point feel, since the springs just progressively compressed.

This version uses an over-center linkage design to have a true bitepoint. this means that the lower half of travel will be with minimal resistance, while the upper half will be of progressively higher resistance, just like in your car.

Aside from that I focused on minimal hardware usage. The prints just need to support the spring force, NOT the force applied to the pedal. Therefore, the only hardware needed is;

• 140mm RC shock/ dampener (1/8th scale)

• 1x M6 socket head bolt (length 18 - 28mm)

• 1x M3 socket head bolt (Length 25 - 35mm)

• 2x 686ZZ bearings (non-bearing version coming soon)

Assembly

Assembly is really straightforward and the design really only fits together 1 way

1.Isolate the Clutch Pedal:
Preparation.

• Remove or position the clutch pedal unit so you have clear, unhindered access to both sides of the frame.

2.Assemble the Middle Linkage:
Needed; M3 Bolt & 686 Bearings.

• Attach the piston end of the shock absorber to the Middle Linkage using the M3 bolt.

• Press the two 686 bearings firmly into the designated pockets on either side of that same middle linkage. Set this completed sub-assembly aside for a moment.

3.Prep the Base Arm Hub:
Needed; Printed Components.

• Gather the Base Arm_L, Base Arm_R, and Base Center_hub. Slide both arms onto the hub. Ensure the integrated bearing pegs face outward (the parts are keyed and will only fit together one way).

4.Mount the Hub to the Pedal Base:
Needed; Mounting Bolt - Baseside.

• While holding the arm-and-hub assembly together, slide it into the base section of your CSL pedal. Align the holes in the printed parts with the frontmost hole on the metal pedal base, then secure it using the two halves of the Mounting bolt - Baseside.

5.Snap the Shock into the Base Arms:
No hardware needed.

• Carefully flex the printed Base Arms slightly inward. Take the shock/linkage assembly you built in Step 2 and pop the two 686 bearings directly over the pegs on the arms. Let the arms spring back to trap the bearings securely.

6.Attach the Offset Linkage:
Needed: Mounting Bolt - Pedalside. & Pedalside_Offsetlinkage

• Mount the Pedalside_Offsetlinkage to the pedal arm using the two halves of the Mounting bolt - Pedalside. Make sure the offset linkage is oriented downwards.

💡Tip: Double-check that the Pedalside_Offsetlinkage points downwards before tightening the M6 bolt. If it's flipped upside down, the over-center geometry won't reach its tipping point properly, and you'll lose that crisp bite-point feel!

7.Final Lock:
Needed; M6 Bolt.

• Secure the remaining free end of the shock to the newly installed offset linkage on the pedal using the M6 bolt.

How it works

Because the pedal rotates around a fixed pivot rather than moving in a straight line, any point on the pedal sweeps through a curved arc. If you mount a spring or shock absorber between a point on the pedal and somewhere on the base where it is colinear to the pedal's pivot, the length of the spring does not compress evenly. Instead, it creates a two-stage geometry:

• Stage 1 (Unpressed to Halfway): As you begin pressing the pedal, the mounting point moves closer to the mounting point on the base, compressing the spring down to (for example) 90% of its original length. During this half of the travel, the spring resists your foot, working with the original spring to push against the pedal to force it back up.

• Stage 2 (Halfway to Fully Pressed): Once the pedal passes the halfway "tipping point," the arc of the mounting point begins moving away from the base again, allowing the spring to expand back to 100% of its length. Past this center line, the spring's force flips—it actually pushes with your movement, pushing against the original spring to give a minimal resistance of the pedal.

This transition creates a distinct two-stage tactile feel, simulating the "clutch bite point" of a car

Adjustment

The middle linkage can be mounted in three different positions along the pedal arm to alter how the over-center geometry behaves:

• Top Position (Recommended): This maximizes the arc sweep, giving you the most pronounced and crisp "bite point" feeling. If you need more stiffness or resistance, it is best to leave the linkage here and simply increase the spring pretension.

• Lowest Position: This flattens out the mechanical advantage. It provides the highest overall pedal resistance, but it significantly flattens out or completely eliminates that distinct two-stage bite point feeling.

• Middle Position: A neutral compromise between the two extremes.

Recommendation: For the most realistic tactile feedback, always keep the linkage in the top position. If the pedal feels too soft, increase the physical spring pretension to add resistance rather than moving the linkage down and losing the bite point effect.