Ultimate Big Bore Shock Maintenance Guide for RC Cars

Maximize Performance, Control, and Durability

Table of Contents

1. Introduction: Why Shock Maintenance Matters

2. What Are Big Bore Shocks?

3. Key Components of Big Bore Shocks

4. Tools and Supplies You’ll Need

5. Choosing the Right Shock Oil Weight

6. How Often Should You Service Big Bore Shocks?

7. Step-by-Step Guide to Rebuilding Big Bore Shocks

8. Tuning Big Bore Shocks for Maximum Performance

9. Common Issues and How to Fix Them

10. Maintenance Tips for Longevity

11. [Placeholder: Insert Your Product Here]

12. Final Thoughts

13. Summary

1. Introduction: Why Shock Maintenance Matters

Big bore shocks are the heart of your RC suspension system. Whether you're bashing over rough terrain or racing on a high-grip track, your shocks do the heavy lifting—literally. But even the best big bore shocks won’t perform well if they’re not regularly maintained.

Neglecting your shocks leads to:

• Poor traction

• Inconsistent handling

• Premature wear on tires and chassis

• Risk of breaking components mid-run

In this blog, we’ll show you how to clean, service, and tune big bore shocks like a pro, ensuring your RC car stays race-ready and trail-tough.

2. What Are Big Bore Shocks?

Big bore shocks are larger-diameter dampers that hold more oil and use wider pistons than standard shocks. The benefits?

• Smoother damping

• Better heat dissipation

• Improved consistency over long runs

• More precise tuning options

They’re especially popular on 1/8 and 1/10 scale RC vehicles, from buggies and truggies to short course trucks and monster trucks.

Typical Big Bore Sizes:

• 1/10 scale: 12mm–16mm bodies

• 1/8 scale: 16mm–20mm+ bodies

3. Key Components of Big Bore Shocks

Understanding the anatomy of a shock is essential for proper maintenance. Here are the major parts:

• Shock Body – Holds the shock oil. Usually made of aluminum or plastic.

• Shock Cap – Seals the top of the shock.

• Piston and Shaft – Moves through the oil to provide damping.

• Shock Oil – Determines the damping rate.

• O-Rings/Seals – Prevent leaks around the shaft.

• Spring – Provides resistance and ride height.

• Preload Collar – Adjusts spring tension.

When one of these fails or wears out, you’ll feel it in how your car handles.

4. Tools and Supplies You’ll Need

Before diving into shock maintenance, gather the following:

Essential Tools:

• Shock pliers

• Pick or O-ring tool

• Phillips and hex drivers

• Needle-nose pliers

• Shock stand or tray

Supplies:

• High-quality shock oil (various weights)

• Rebuild kit (O-rings, bladders, seals)

• Clean rags or paper towels

• Isopropyl alcohol for cleaning

• Silicone grease for seals

• Caliper (optional, for measuring preload and shaft lengths)

5. Choosing the Right Shock Oil Weight

Shock oil weight is crucial in how your RC car absorbs impacts and handles terrain.

Common Shock Oil Ranges:

• 1/10 scale buggies and trucks: 25wt – 50wt

• 1/8 scale buggies and truggies: 35wt – 70wt

Conversion Chart: CST vs WT

How to Choose:

• Thinner Oil (Lower WT): Faster piston movement, more plush suspension

• Thicker Oil (Higher WT): Slower piston movement, stiffer feel

Factors that affect your oil weight choice:

• Track surface (loose vs grippy)

• Weather (colder temps = thicker oil needed)

• Vehicle weight and power

Pro Tip: Start with the manufacturer’s baseline recommendation, then tune up or down in 5wt increments.

6. How Often Should You Service Big Bore Shocks?

General Guideline:

• Every 5–10 runs for bashers

• Every race day for competitive racers

• Immediately after wet, muddy, or sandy conditions

Signs your shocks need attention:

• Loss of rebound

• Leaking oil around shaft or cap

• Clicking or sticking sounds

• Inconsistent cornering or bottoming out

7. Step-by-Step Guide to Rebuilding Big Bore Shocks

Step 1: Remove the Shocks

Use your hex driver to remove the shocks from the suspension arms. Label front vs rear if they’re different lengths or settings.

Step 2: Drain the Old Oil

Unscrew the cap and slowly cycle the shock shaft to push out the oil. Let it drain fully into a container or rag.

Step 3: Disassemble and Inspect

• Remove the spring and preload collar

• Carefully unscrew the lower cartridge

• Remove shaft, piston, O-rings, and seals

• Check for bent shafts, cracked pistons, or deteriorated O-rings

Step 4: Clean Everything

Wipe down all parts with isopropyl alcohol. Use a brush for stubborn gunk. Avoid scratching the shock shaft!

Step 5: Rebuild with Fresh Seals

Install new O-rings and apply a dab of silicone grease. Reinstall shaft and piston into the shock body carefully.

Step 6: Fill with Oil

• Slowly fill shock body 3/4 full with oil

• Cycle the shaft to remove air bubbles

• Top off with oil and let sit for 5–10 minutes

Step 7: Bleed and Seal

Depending on your shock type:

• Emulsion shocks – Tighten cap slowly while bleeding excess oil

• Bladder shocks – Insert bladder first, then cap while avoiding overflow

Make sure rebound is consistent across all shocks.

Step 8: Reinstall and Test

Attach the shocks back to your rig. Compress them to verify smooth operation with no leaks.

8. Tuning Big Bore Shocks for Maximum Performance

Shock tuning involves more than just oil weights. Here's what you can tweak:

Springs:

• Heavier springs = more resistance

• Lighter springs = more articulation and softer ride

Pistons:

• Pistons with more holes or larger holes = faster oil flow

• Fewer or smaller holes = more damping

Preload and Ride Height:

Use preload collars to adjust how much initial tension is on the spring. This affects how quickly weight transfers during acceleration, braking, or cornering.

Front vs Rear Bias:

• Stiffer rear = more steering

• Stiffer front = more stability

9. Common Issues and How to Fix Them

10. Maintenance Tips for Longevity

• Always store your RC car upright so oil doesn’t pool in one side

• Avoid over-tightening caps—this can crush bladders or seals

• Label your oil bottles with last-used date and conditions

• Use a shock dyno (if available) for consistent performance readings

• Keep a shock logbook to track oil changes and tuning setups