ARRMA Kraton upgrades are the most searched topic among new Kraton owners, and for good reason. The 6S V5 BLX is an absolute beast out of the box, but after a few hard sessions, certain parts start showing their limits. You didn’t spend $550+ on this truck to watch it limp home with a stripped servo or bent suspension arm.
Here’s what we’ll cover: the five upgrades that actually prevent failures and improve performance — not the flashy stuff that looks cool on Instagram but does nothing for durability. We’ve run Kratons since the V2 days, broken nearly everything breakable, and learned exactly where this truck needs reinforcement before it needs it.
The Kraton 6S weighs 5.3kg (11.7lbs) ready-to-run and pushes 60+ mph with the right gearing. That’s a lot of mass moving fast, and the stock components weren’t all designed to handle years of abuse. Some parts are overbuilt. Others are clearly cost-engineered. Knowing the difference saves you money and trail-side frustration.
Whether you’re launching off backyard kickers, ripping through gravel pits, or just doing full-throttle parking lot runs, these five upgrades address the actual weak points. No fluff, no “maybe consider this someday” — just the parts that matter, in priority order, with real specs and install context.
Why Stock Parts Fail — Understanding the Kraton’s Weak Points
The stock Kraton 6S V5 fails in predictable places because ARRMA balanced durability against price point. The servo, front suspension arms, and stock pinion are the first casualties in hard bashing — usually within 20-30 packs for aggressive drivers.
ARRMA uses a Spektrum S652 servo in the RTR Kraton. It’s rated at 6.5kg-cm torque, which sounds reasonable until you realize those massive 17mm hex wheels create enormous leverage. One hard landing with the wheels turned, and you’re looking at stripped gears or a dead servo.
The front upper A-arms are composite plastic. They flex under load, which is actually fine for absorbing impacts. But repeated stress cycles cause fatigue cracks, especially at the shock mounting points. We’ve seen arms snap clean off after 40-50 packs of jump-heavy bashing.
Stock shock oil is typically 30-35wt, tuned for a balance of comfort and control. But the Kraton’s 150mm of suspension travel means the shocks bottom out hard on big landings. Heavier oil slows the compression, protecting the chassis and giving you more control.
The RTR batteries (if you bought the combo) are usually adequate but not exceptional. They sag under load, reducing top speed and punch. Quality hardcase packs with higher C-ratings transform how the truck accelerates.
Finally, the stock pinion is aluminum. It’s light and quiet, but it wears fast against the steel spur gear. After 30-40 packs, you’ll notice slop in the mesh. Steel pinions last essentially forever.
→ ARRMA Kraton 6S BLX — if you’re still deciding on the truck itself, the V5 is the current generation with improved electronics and the Spektrum Firma 150A ESC.
Upgrade #1: High-Torque Metal Gear Servo — The Single Most Important Change
A 25kg-cm metal gear servo is the single most important Kraton upgrade because the stock servo fails first and fails catastrophically. When it strips mid-run, you have zero steering — and a 5.3kg truck at 40mph with no steering is a bad day.
The math is simple. The Kraton runs 17mm hex wheels with massive Dboots Copperhead 2 tires (150mm diameter). That tire diameter creates a long lever arm from the steering link to the ground contact patch. Every bump, every landing, every high-speed correction multiplies the force on the servo.
We’ve tested servos from 15kg to 35kg torque ratings. The sweet spot for 6S Kraton use is 25-30kg. Below that, you’ll still get gear stripping on hard landings. Above that, you’re paying for torque you don’t need and adding unnecessary weight.
Speed matters too. Look for servos rated at 0.12-0.15 seconds per 60 degrees at 6V. Anything slower than 0.18 seconds feels sluggish in a truck this size. The Kraton’s steering geometry is already somewhat slow due to Ackermann angles — a slow servo compounds that.
Metal gears are non-negotiable. Plastic or nylon gears will strip within 10 packs of aggressive driving. Steel or titanium gears handle the shock loads without deformation.
Waterproofing is important if you bash in wet conditions. Most quality servos are water-resistant, but truly waterproof units have sealed cases and O-rings on the output shaft. Check the IP rating — IP67 means full submersion protection.
→ Metal Gear Servo 25kg — look for units with steel gears, 0.12s speed, and waterproof ratings for all-weather Kraton bashing.
Installation takes about 15 minutes. Remove the four screws holding the stock servo, disconnect the lead from the receiver, and reverse the process with the new unit. You may need to adjust the servo horn position to center the steering — do this before tightening the horn screw.
One tip: apply a tiny drop of blue threadlocker to the servo horn screw. The vibration from bashing can loosen it over time, and a loose horn means inconsistent steering.
Upgrade #2: Aluminum Front Upper Suspension Arms — Preventing the Snap
Aluminum front upper suspension arms eliminate the most common structural failure point on the Kraton. The stock composite arms flex under load, which eventually causes fatigue cracking at the shock mount and ball cup areas.
Here’s the thing about aluminum arms: they don’t flex, they bend. That sounds worse, but it’s actually better for durability. A bent aluminum arm still functions — it just needs straightening or replacement. A cracked composite arm fails completely, often mid-air.
The Kraton uses the same upper arm geometry as the 8S trucks, which means aftermarket aluminum arms designed for the Kraton 8S fit the 6S perfectly. This gives you more options and often better pricing since the 8S market is larger.
Weight difference is minimal. Stock composite upper arms weigh approximately 28g each. Aluminum versions run 35-42g depending on the manufacturer. That’s less than 30g of unsprung weight per side — imperceptible in real-world handling.
Some drivers worry about aluminum transferring more shock to the chassis. In practice, the difference is negligible because the shocks and lower arms absorb the vast majority of impact energy. The upper arms mainly locate the hub carrier — they’re not primary load-bearing members.
→ Aluminum Front Upper Arms — 8S-compatible arms fit the 6S Kraton and offer excellent durability for jump-heavy bashing.
Why just the front? The rear upper arms see less stress because the rear of the truck is heavier (motor, ESC, batteries) and lands more flat. Front arms take the brunt of nose-dive landings and off-angle impacts. If you’re doing extreme freestyle, upgrade both — but front-first gives you 80% of the benefit.
Installation requires removing the shock, popping out the ball cups, and unbolting the arm from the chassis and hub carrier. Total time is about 20 minutes per side. Inspect the ball cups during removal — if they’re loose or cracked, replace them with fresh ones.
We’ve covered similar durability concerns for the Notorious in our pre-jump checklist — the truggy shares many suspension components with the Kraton.
Upgrade #3: Heavier Shock Oil — The Cheapest Performance Improvement
Upgrading to 45-50wt shock oil costs under $15 and transforms how the Kraton handles jumps and rough terrain. It’s the highest value-to-cost upgrade on this entire list.
Stock Kraton shocks come filled with approximately 30-35wt oil. This weight is tuned for general-purpose driving — responsive enough for technical crawling, soft enough for comfort on pavement. But for bashing, it’s too thin.
Thicker oil slows the compression stroke, which does three important things. First, it prevents harsh bottoming on big landings. Second, it reduces chassis roll in high-speed corners. Third, it gives the suspension more “support” when preloading for jumps.
The Kraton’s shocks have 150mm of travel with 16mm bore bodies. That’s a lot of oil volume to move through the piston. Going from 35wt to 50wt increases damping force by roughly 40% — noticeable but not harsh.
Don’t go too heavy. We’ve tested 60wt and 70wt oils in the Kraton, and they make the suspension feel wooden. You lose the plushness that makes monster trucks fun. Stick to 45-50wt for the best balance.
Silicone shock oil is measured in centistokes (cSt) or weight (wt). These scales aren’t perfectly standardized between brands, so a “50wt” from one company might feel different than another. Stick to known brands like Associated, Team Losi, or Traxxas for consistent viscosity.
Changing shock oil requires disassembling the shocks, cleaning out the old oil, and refilling with new. It sounds intimidating but takes about 45 minutes for all four shocks once you’ve done it once. Plenty of YouTube tutorials cover the process step-by-step.
While you have the shocks apart, inspect the O-rings and bladders. If the shocks have been leaking, replace these seals — they’re cheap and often the source of damping inconsistency.
One pro tip: fill the shocks slightly overfull, then compress them slowly to bleed out air bubbles before installing the caps. Air in the shock creates inconsistent damping and a “springy” feel that’s hard to tune out.
Upgrade #4: Quality Hardcase 6S LiPo Batteries — Power That Doesn’t Sag
Quality 6S LiPo batteries with high C-ratings deliver consistent power throughout your run and protect against damage in crashes. Cheap packs sag under load and puff after impacts — neither is acceptable in a $550+ truck.
The Kraton uses a dual-battery tray designed for two 3S packs wired in series (6S total) or a single 6S pack with an adapter. Most bashers prefer two 3S packs because they’re more common, cheaper, and easier to balance charge.
Capacity matters, but C-rating matters more. A 5000mAh pack rated at 50C can deliver 250 amps continuous. The Kraton’s Firma 4074 2050Kv motor pulls around 80-100 amps at full throttle, so 50C gives you plenty of headroom. Lower C-ratings (30C or less) sag under load, reducing punch and top speed.
Hardcase packs are essential for bashing. Soft-pack LiPos can puncture on sharp impacts, causing fires. Hardcases absorb impacts and protect the cells. The weight difference is minimal — maybe 50g per pack — and the safety margin is worth it.
In 2026, quality 6S-capable battery pairs (two 3S 5000mAh 50C hardcase packs) run $80-120 depending on brand. Zeee, Gens Ace, and Ovonic are popular budget-friendly options with good track records. Premium brands like Spektrum and MaxAmps cost more but offer better quality control.
→ 6S LiPo Battery Hardcase Pair — 5000mAh 50C hardcase packs deliver the punch the Kraton needs without voltage sag or safety concerns.
Battery fit is important. The Kraton’s tray accepts packs up to approximately 139mm x 47mm x 50mm per side. Measure before buying — oversized packs won’t fit without modification.
Always use a quality balance charger. Charging 6S packs at 1C (5 amps for 5000mAh packs) takes about an hour and maximizes battery lifespan. Fast charging at 2C or higher generates heat and accelerates cell degradation.
We’ve covered battery basics in more detail in our Grom battery compatibility guide — the principles apply across all ARRMA trucks.
Upgrade #5: Steel Pinion Gear Set — Eliminating Drivetrain Slop
A steel pinion gear eliminates the wear that causes drivetrain slop and noise. The stock aluminum pinion meshes against a steel spur gear, and softer aluminum always loses that battle.
The Kraton 6S uses Mod 1 pitch gearing with a stock 15T pinion. This gives a gear ratio of approximately 2.85:1 with the 43T spur gear (after accounting for the internal transmission ratio). That’s aggressive gearing that prioritizes acceleration and wheelies over top speed.
Aluminum pinions wear in two ways. First, the tooth profiles round off, creating slop in the mesh. Second, the teeth can actually shear under high-torque loads like hard acceleration from a standstill. Steel pinions resist both failure modes.
Steel pinions are slightly heavier (maybe 5g difference) and slightly louder due to metal-on-metal contact. Neither is noticeable in real-world driving. The durability benefit far outweighs these minor drawbacks.
When upgrading, consider your gearing goals. The stock 15T pinion is good for general bashing. A 14T pinion reduces top speed but improves torque and reduces motor heat — better for technical terrain. A 16T or 17T increases top speed but runs the motor hotter and reduces low-end punch.
→ Pinion Gear Set Steel — Mod 1 steel pinions in multiple tooth counts let you tune gearing while eliminating the wear issues of aluminum.
Gear mesh is critical. Too tight creates friction and heat. Too loose creates slop and accelerates wear. The paper test works: slide a piece of printer paper between the pinion and spur, tighten the motor mount, then remove the paper. This leaves approximately 0.1mm of clearance — ideal for Mod 1 gears.
Apply a thin layer of diff grease to the pinion teeth before installation. This reduces initial wear and quiets the mesh slightly. Reapply every 10-15 packs or whenever the gears start sounding dry.
We’ve discussed gearing effects on handling in our Typhon setup guide — overgearing causes similar issues on both platforms.
Upgrades That Don’t Matter (Yet) — Where NOT to Spend Money First
Certain popular upgrades don’t provide meaningful benefits until you’ve addressed the five priorities above. Save these for later — or skip them entirely.
Aluminum shock caps: The stock composite caps work fine. Aluminum caps look cool but don’t improve performance. They can actually crack under severe impacts because aluminum doesn’t flex like composite.
Full aluminum suspension: Upgrading every A-arm to aluminum adds weight without proportional durability gains. The front uppers are the weak point — the rest of the suspension is adequately strong for 6S power.
Wheelie bar: Fun for parking lot stunts, but it adds weight, reduces ground clearance, and catches on obstacles during technical bashing. Most experienced drivers remove them.
Motor upgrades: The stock Firma 4074 2050Kv motor handles 6S power without overheating in normal use. Upgrading to a higher-Kv motor increases speed but also increases stress on every other drivetrain component. Not worth it until you’ve reinforced everything else.
ESC upgrades: The Firma 150A ESC is already overkill for the stock motor. It has headroom for moderate motor upgrades without replacement.
Chassis braces: The Kraton’s chassis is already quite rigid. Braces add weight and can actually concentrate stress at the brace endpoints, causing cracks in different locations. Skip unless you’re doing extreme freestyle.
Installation Priority Order — What to Upgrade First
If budget is limited, upgrade in this order: servo, shock oil, batteries, front upper arms, steel pinion. This sequence addresses failure probability and performance impact.
The servo fails most often and most catastrophically. A dead servo mid-run ends your session immediately. Upgrade this first, period.
Shock oil is the cheapest upgrade with the biggest handling improvement. Do this second — it takes an hour and costs $15.
Batteries affect every aspect of performance. If your stock packs are sagging or you’re using low-quality cells, upgrading transforms the driving experience. Third priority.
Front upper arms fail eventually but not immediately. They’re a preventive upgrade — install them before a big bashing session or event, but don’t rush if you’re just doing casual backyard runs. Fourth priority.
The steel pinion is a long-term durability upgrade. The stock aluminum pinion lasts 30-50 packs before showing significant wear. Replace it when you notice slop, or proactively during your next maintenance session. Fifth priority.
Terrain-Specific Considerations — Tuning for Your Bashing Style
Different terrains stress different components. Adjusting your upgrade priorities based on where you bash maximizes value.
Dirt and gravel: Dust infiltrates everything. The servo is especially vulnerable because dust enters through the output shaft seal. Prioritize waterproof/dustproof servos. Consider adding foam air filters to the chassis vents.
Pavement and parking lots: High-speed impacts are more common. The front upper arms see maximum stress from nose-dive landings on hard surfaces. Prioritize aluminum arms and heavier shock oil.
Grass and soft surfaces: The suspension works harder to maintain traction. Stock shock oil is actually closer to optimal here — you might only need 40-45wt instead of 50wt.
Wet conditions: Water kills electronics. Prioritize waterproof servos and ensure all chassis seals are intact. Consider conformal coating the receiver and ESC if you bash in rain regularly.
Skate parks and freestyle: Everything takes more abuse. All five upgrades become essential, and you should also inspect the chassis for cracks after every session.
Cost Breakdown — Budgeting Your Kraton Upgrades
The total cost for all five upgrades runs approximately $180-280 depending on brand choices. Here’s the breakdown for 2026 pricing.
| Upgrade | Budget Option | Premium Option |
|---|---|---|
| Metal Gear Servo (25kg) | $25-35 | $60-80 |
| Aluminum Front Upper Arms | $30-40 | $55-70 |
| Shock Oil (45-50wt) | $8-12 | $15-20 |
| 6S LiPo Battery Pair | $80-100 | $140-180 |
| Steel Pinion Gear Set | $12-18 | $25-35 |
| Total | $155-205 | $295-385 |
Budget options work fine for most bashers. Premium options offer better quality control, longer lifespan, and sometimes better performance — but the difference isn’t dramatic for recreational use.
Spread the purchases over time if needed. The servo and shock oil together cost under $50 and address the most critical issues. Add batteries when your current packs start sagging. Install arms and pinion during a scheduled maintenance session.
Frequently Asked Questions
What’s the most important upgrade for ARRMA Kraton durability?
A metal gear servo rated at 25kg or higher torque is the most important Kraton upgrade. The stock servo strips gears frequently under hard use, leaving you with zero steering mid-run. Waterproof models with steel gears last years of aggressive bashing.
Do I need aluminum suspension arms on the Kraton 6S?
Front upper aluminum arms are highly recommended for jump-heavy bashing. The stock composite arms eventually fatigue-crack at the shock mounts. Rear arms see less stress and can remain stock unless you’re doing extreme freestyle.
What shock oil weight should I use in the Kraton?
Most bashers find 45-50wt shock oil ideal for the Kraton 6S. Stock oil is 30-35wt, which allows too much bottoming on big landings. Heavier oil slows compression without making the ride harsh.
Are aluminum upgrades worth it on the Kraton?
Selective aluminum upgrades are worth it — specifically front upper arms and possibly steering components. Full aluminum suspension adds unnecessary weight and can actually crack under impacts where composite would flex.
How long do stock Kraton parts last before needing upgrades?
Stock servos typically fail within 20-30 battery packs of aggressive bashing. Front upper arms last 40-50 packs. Aluminum pinions show wear around 30-40 packs. Casual drivers may get significantly longer life from stock parts.
Should I upgrade the Kraton motor or ESC?
The stock Firma 4074 2050Kv motor and 150A ESC handle 6S power without issues for most drivers. Upgrade these only after reinforcing the drivetrain and suspension — more power accelerates wear on weak points.
What’s the difference between Kraton 6S and 8S upgrade parts?
Many suspension components are shared between the Kraton 6S and 8S, including upper arms and shock bodies. The 8S uses a larger motor, ESC, and different chassis. Always verify part compatibility before ordering.
Final Verdict — Building a Bulletproof Kraton
These five ARRMA Kraton upgrades transform a great truck into a nearly unbreakable one. The servo, front upper arms, shock oil, batteries, and steel pinion address every common failure point we’ve encountered in years of hard bashing.
The total investment — $180-280 depending on brand choices — is modest compared to the cost of the truck itself. More importantly, these upgrades prevent the frustration of mid-session failures and the expense of emergency part orders.
Start with the servo. It’s the component most likely to fail and the failure with the worst consequences. A stripped servo at 40mph is genuinely dangerous. Spend $30-60 on a quality metal-gear unit and never worry about it again.
Add shock oil and batteries next. These are the upgrades that improve how the truck drives, not just how long it lasts. Heavier oil gives you more control on jumps. Quality batteries deliver consistent power without sag.
Install aluminum front upper arms before your next big bashing session. They’re preventive maintenance — the stock arms work fine until they suddenly don’t. Having aluminum arms already installed means one less thing to worry about.
Replace the pinion with steel whenever you’re doing drivetrain maintenance. It’s not urgent, but it eliminates a slow-developing problem before it becomes noticeable.
Skip the flashy stuff — full aluminum suspension, wheelie bars, motor upgrades — until you’ve addressed these fundamentals. The Kraton is already an incredibly capable truck. These five upgrades simply let it reach its potential without constant repairs.
If you’re still deciding between the Kraton and its stunt-focused sibling, our Kraton vs Outcast comparison breaks down the key differences. Both trucks benefit from these same upgrades — the platforms share most components.
Now get out there and bash. The Kraton was built for abuse. With these upgrades, it’ll take everything you throw at it and ask for more.
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