Key takeaways
- 60A (Soft): Provides a longer pedal travel, ideal for simulating older road cars or for drivers who prefer ankle-joint movement over pure force.
- 80A (Medium): A balanced setting that offers a distinct bite point with progressive resistance.
- 90A (Hard): Extremely stiff with minimal physical travel, simulating a modern Formula 1 or LMP car where braking is controlled almost entirely by pressure.
In the world of high-performance sim racing, your brake pedal is the single most critical component for shaving tenths of a second off your lap times. Unlike standard potentiometer pedals that measure how far you press the pedal, load cell pedals measure how much force you apply, mimicking the hydraulic pressure system of a real race car. At the heart of this system is the elastomer stack—small polyurethane bushings that compress under pressure to simulate brake resistance.
Learning how to adjust load cell pedal elastomer stiffness is a vital skill for dialing in muscle memory and ensuring consistent trail braking. However, executing this adjustment incorrectly can lead to serious performance and physical issues. If your stack is poorly configured, you risk causing physical joint strain in your ankle and knee from excessive force, or conversely, making the pedal so soft that you constantly lock your wheels or trigger ABS prematurely. Furthermore, improper assembly can unevenly distribute force, permanently damaging the delicate 50kg to 200kg load cell sensor or bending the pedal shaft itself. This step-by-step guide will help you configure your pedal stack safely and precisely for optimal performance.
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What You Need
Before you begin adjusting your pedals, gather the necessary tools and replacement parts. Having everything organized prevents damage to the fine threads on your pedal shafts and keeps your workspace clean.
| Item | Why You Need It | Optional? |
|---|---|---|
| Replacement Elastomer Kit | A set of polyurethane bushings of varying Shore hardness ratings (typically ranging from 50A for soft to 90A for extremely stiff). Standard sizes range from 15mm to 25mm in diameter. | No |
| Allen Keys / Hex Wrenches | Usually 4mm, 5mm, or 6mm keys, depending on your pedal brand, to loosen locknuts, retaining bolts, or shaft pins. | No |
| Synthetic PTFE or Silicone Grease | To lubricate the interfaces between elastomers and metal spacers. This prevents squeaking, binding, and premature tearing of the polyurethane. | Yes (Highly Recommended) |
| Vernier Calipers or Ruler | To measure the exact height of your elastomer stack and preload distance, ensuring symmetry and repeatable setups. | Yes |
| Microfiber Cloth | To wipe away old, dirty grease, dust, and metal shavings from the pedal shaft before reassembly. | No |
Step-by-Step
Adjusting your load cell pedal elastomer stiffness is a physical and digital process. Follow these steps carefully to ensure you do not strip any threads or ruin your calibration.
Step 1: Power Down and Stabilize Your Rig (Time: 5 minutes)
Before touching any mechanical components, disconnect your pedal set’s USB cable from your PC or console. This prevents any accidental electrical surges while handling the metal frame and ensures you do not send erratic inputs to your calibration software. Ensure your racing rig or pedal plate is locked in a stable, flat position so that parts do not roll away during disassembly.
Step 2: Remove the Elastomer Shaft Retention System (Time: 10 minutes)
Locate the central shaft on your brake pedal assembly that houses the elastomer stack. Most modern load cell pedals use a threaded rod secured by a locknut, a quick-release pin, or a knurled preload wheel at the rear of the pedal arm. Use your hex wrench to loosen the retaining nut or carefully slide out the quick-release pin. Hold the elastomer stack with one hand while doing this so the internal spring or spacers do not pop out abruptly under residual tension.
Step 3: Analyze and Select Your New Elastomer Stack (Time: 10 minutes)
Once the shaft is free, slide off the existing elastomers and metal washers. Inspect your elastomer kit. Elastomers are rated by Shore hardness (the higher the number, the stiffer the rubber). For example:
- 60A (Soft): Provides a longer pedal travel, ideal for simulating older road cars or for drivers who prefer ankle-joint movement over pure force.
- 80A (Medium): A balanced setting that offers a distinct bite point with progressive resistance.
- 90A (Hard): Extremely stiff with minimal physical travel, simulating a modern Formula 1 or LMP car where braking is controlled almost entirely by pressure.
Decide on your configuration. You can mix and match (e.g., placing a soft 60A elastomer at the front of the stack to simulate pad-to-rotor contact, followed by two stiff 80A elastomers for a solid wooden-wall feel). Always place a metal spacer washer between different elastomer durometers to prevent them from bleeding into and damaging one another under compression.
Step 4: Clean and Lubricate the Shaft and Components (Time: 5 minutes)
Use your microfiber cloth to thoroughly clean the central shaft, metal washers, and the inside channels of your new elastomers. Apply a thin, even layer of synthetic PTFE or dry silicone grease to the outer surfaces of the elastomers and the faces of the metal washers. This lubrication minimizes friction, eliminates distracting squeaks during intense driving sessions, and extends the lifespan of the polyurethane by reducing heat buildup.
Step 5: Reassemble the Stack and Adjust Preload (Time: 10 minutes)
Slide the new elastomer stack back onto the shaft in your chosen order. Re-insert the shaft into the pedal arm bracket and tighten the retaining nut or pin. Next, adjust the preload wheel. Preload is the initial compression applied to the elastomers before you press the pedal. Use your calipers to measure the compressed stack height. A small amount of preload (1mm to 2mm of compression) removes dead-zone play, ensuring the pedal reacts instantly to your foot’s input.
Step 6: Recalibrate the Pedal Software (Time: 10 minutes)
Changing the physical stiffness of your pedal completely alters the voltage curve sent to the load cell sensor. Reconnect your pedals to your PC. Open your pedal manufacturer’s calibration software (or a universal tool like DIView). Press the brake pedal with your maximum comfortable braking force and set this as your new 100% threshold. If you transitioned to a stiffer stack, you will need to apply more physical force to reach 100%; if you went softer, you must lower the software threshold to prevent reaching maximum braking too early in the pedal travel.
Mistakes to Avoid
- Using Petroleum-Based Lubricants: Never use WD-40, mineral oil, or petroleum jelly on polyurethane elastomers. These substances chemically break down the polyurethane, causing it to liquefy, crack, and fail within weeks. Stick strictly to synthetic silicone or PTFE grease.
- Skipping the Metal Spacers: Placing two elastomers of different hardness directly against each other without a metal washer causes the softer elastomer to expand into the bore of the harder one, destroying both pieces and creating an erratic, non-linear braking feel.
- Over-tightening the Preload: Tightening the preload adjustment wheel so much that the elastomers are permanently crushed limits their travel and can overload the load cell sensor at rest, causing “brake dragging” in your telemetry.
- Neglecting Software Calibration: Failing to recalibrate your software after a mechanical change can result in a pedal that either cannot reach 100% braking force or reaches maximum output with only a slight tap, completely undermining the benefit of your physical adjustment.
How Often
How frequently you need to adjust or service your load cell elastomers depends heavily on your weekly usage. For casual sim racers logging 5 to 10 hours a week, a quick inspection and re-lubrication every six months is sufficient. If you are a competitive league racer spending 20+ hours a week on the rig, you should check your elastomer stack every three months.
Polyurethane elastomers naturally suffer from “material creep” over time, meaning they permanently lose some of their elasticity and structural memory under repeated high-force compression. Plan to replace your elastomer bushings entirely every 12 to 18 months to maintain a consistent, predictable brake pedal curve. As sim racing hardware reaches new heights of realism in 2026, keeping these small components fresh is key to maintaining your competitive edge.
When to Call a Pro or Replace
While adjusting elastomers is a DIY task, there are times when physical wear indicates it is time to replace your components or upgrade your entire pedal set. If you notice deep cracks, flaking, or a permanent “pancake” deformation in your elastomers, they must be discarded immediately. If your software telemetry displays flickering inputs or fails to return to 0% when you release your foot, your load cell sensor may be bent or failing, requiring a replacement sensor from the manufacturer.
If you find yourself constantly struggling to get the right progression from simple elastomer stacks, it may be time to upgrade to a professional-grade pedal set with superior engineering. For instance, the SIMSONN PRO X Ultra Sim Racing Pedals PC Racing Simulator Load Cell HE Hydraulic Pedals Support Haptic Reactor (PRO X Ultra P3-H3-Plate), which typically retails in the $300 to $400 range (specifically priced around $350), offers a highly advanced load cell system combined with hydraulic dampers and haptic feedback compatibility. Upgrading to a premium system like this provides a wider envelope of physical adjustments, making it much easier to fine-tune your braking pressure without constantly swapping out individual bushings.
FAQ
What is Shore hardness, and how does it affect my sim racing pedals?
Shore hardness is a standardized scale (commonly Shore A for rubbers and soft plastics) used to measure a material’s resistance to indentation. In sim racing, a lower rating like 60A means the elastomer is soft and compressible, giving you more physical pedal travel. A higher rating like 90A is incredibly dense, providing a stiff pedal with minimal travel where your braking is modulated almost entirely by how hard you press, rather than how far.
Can I use dry graphite powder to lubricate my pedal elastomers?
No. While dry graphite is excellent for lock cylinders and metal-on-metal slides, it does not provide the cushioning barrier needed for polyurethane elastomers under high-compression loads. Dry graphite can also migrate into your load cell’s electrical housing or RJ connectors, causing signal shorts. Stick to a high-quality synthetic silicone or PTFE-based grease.
Why does my brake pedal feel softer after a few weeks of use?
This is a natural physical process called “breaking in.” Brand new polyurethane elastomers have a stiff initial surface tension. After a few hours of heavy compression, the polymer chains relax slightly, resulting in a minor drop in stiffness. Once broken in, their performance will stabilize for several months before gradual wear eventually requires their replacement.
Do I need to change my in-game brake linearity settings after adjusting my elastomers?
Yes. When you change the physical stiffness of your pedal, your brain and foot must adapt to a new force curve. If you have switched to a much stiffer elastomer stack, you may want to adjust your game’s brake sensitivity or linearity curve to be more linear (a value of 1.00), as your foot is now directly controlling the pressure. For softer stacks, a slightly progressive curve can help prevent accidental lockups during the initial phase of pedal travel.
