KTM 18187U5701 Rear Shock Suspension Xact Xtrig 125-450

( Manufacturer Part Number: 18187U5701 ), ( Part Type: Shock Suspension ), ( Placement On Vehicle: Rear )

Review KTM Rear Shock Suspension Wp Xact Xtrig Fc Mc fits 350SXF TC 2021

The **KTM 350 SX-F 2021 (Model Code: 18187U5701)** stands as a masterclass in off-road engineering, blending razor-sharp handling, cutting-edge technology, and relentless performance to redefine what a 350cc motocross bike can achieve. At its core, this machine is a testament to KTM s relentless pursuit of innovation, featuring a **WP XACT rear suspension system**, a revolutionary leap forward in motocross shock technology. The XACT system dynamically adjusts damping in real-time, responding to the rider s input and terrain conditions with precision, ensuring optimal traction, control, and comfort whether you re carving through tight corners, launching off jumps, or navigating rough, uneven trails. Paired with the **WP X-TRIG electronic suspension**, this bike offers unparalleled customization, allowing riders to fine-tune their suspension settings via the intuitive **KTM FC (Fully Connected) system** on their smartphone. The FC app not only lets you adjust compression, rebound, and spring preload but also provides data-driven insights into your riding style, helping you optimize performance for different tracks and conditions.

The **2021 350 SX-F** is built on KTM s legendary **Aluminum Spaceframe chassis**, a lightweight yet ultra-stiff structure that delivers exceptional rigidity and agility, translating rider input into razor-sharp responses. The bike s **43mm WP XPLOR inverted fork** is a standout feature, offering superior damping and rebound control, while its **adjustable preload** allows for quick tuning to match rider weight and track demands. The **KTM WP XACT rear shock** isn t just about performance it s about intelligence. By continuously monitoring wheel movement, the XACT system automatically adjusts damping to maintain optimal wheel contact, reducing bounce and improving stability, especially during aggressive riding or on uneven terrain. This level of sophistication ensures that the 350 SX-F doesn t just keep up with the rider; it anticipates their needs, making it one of the most rider-responsive bikes on the market.

Under the hood, the **350 SX-F** is powered by KTM s **high-revving, fuel-injected 349cc single-cylinder engine**, a masterpiece of efficiency and power delivery. The **ECU-tuned engine** produces a thrilling, linear powerband that punches hard from mid-range while maintaining smooth, predictable throttle response. The **KTM FC (Fully Connected) system** extends beyond suspension, offering riders the ability to adjust engine maps, throttle response, and even traction control settings via their smartphone. This level of connectivity not only enhances performance but also allows riders to fine-tune their bike for different track conditions, whether it s a loose, sandy section or a tight, technical trail. The **KTM X-Box** also integrates with the FC app, providing real-time telemetry data, including RPM, speed, and suspension movement, giving riders invaluable feedback to sharpen their skills and optimize their setup.

The **2021 350 SX-F** is further equipped with **KTM s advanced braking system**, featuring a **front disc brake with a 260mm rotor** and **rear disc brake with a 220mm rotor**, both paired with **Brembo calipers** for exceptional stopping power and modulation. The bike s **KTM 4-in-1 exhaust system** not only delivers a deep, aggressive growl but also contributes to weight savings and improved handling dynamics. The **KTM 2021 model year** also introduces refinements to the **airbox and fueling system**, ensuring consistent power delivery even under heavy throttle, while the **updated rider aids** such as the **adjustable footpegs, ergonomic handlebars, and refined seating position** enhance comfort and control during long sessions.

Whether you're a professional rider pushing the limits on the track or an enthusiast looking to dominate local motocross events, the **KTM 350 SX-F 2021** is a bike that demands respect. Its **WP XACT and X-TRIG suspension**, **smart FC connectivity**, and **high-performance engine** combine to create a machine that s not just fast but also incredibly versatile. With its **lightweight chassis**, **precise handling**, and **cutting-edge technology**, this bike isn t just a competitor on the track it s a statement of what modern motocross should be: **intelligent, responsive, and relentlessly fun**.

### **Pros and Cons of buying a KTM 350 SX-F 2021 (WP XACT XTRIG, Rear Shock Suspension, 125-450 TC/FC)**

#### **Pros**

1. **Performance and Power**

- The 350 SX-F is one of the most powerful and capable 350cc cross-country bikes, with a high-revving, fuel-injected engine that delivers strong mid-to-upper-range power. It s built for aggressive trail riding, enduro, and light motocross, making it versatile for different terrains.

- The **WP XACT XTRIG** suspension system provides precise, adjustable damping, allowing riders to fine-tune the bike for their weight, skill level, and riding style. This is a significant upgrade over older shock systems, offering better control and comfort on rough trails.

2. **Lightweight and Agile**

- KTM s aluminum frame keeps the bike lightweight (around **210 lbs / 95 kg**), improving maneuverability and making it easier to handle on technical trails. This is particularly beneficial for riders who prioritize agility over brute power.

3. **Advanced Suspension Technology**

- The **rear shock suspension** (WP XACT XTRIG) is one of the best in its class, offering **125mm of travel** (adjustable for compression, rebound, and preload). This system excels in absorbing impacts, improving traction, and reducing rider fatigue on long rides.

- The **front WP XACT forks** (also adjustable) complement the rear shock, providing a balanced and responsive ride. The **XTRIG** technology allows for digital tuning via the KTM PID system, which can be adjusted on the fly or via the KTM app.

4. **Durability and Reliability**

- KTM bikes are known for their **durability**, with high-quality components that can withstand rough use. The 350 SX-F s engine and drivetrain are robust, and the frame is designed to handle heavy abuse.

- The **TC/FC (Trail/Factory Cross) setup** means the bike is built for both trail riding and light motocross, making it a good all-rounder for riders who don t want to commit to a purely motocross or enduro-specific bike.

5. **Fuel Injection and Electronic Assistance**

- The **fuel-injected engine** ensures consistent power delivery, reducing the risk of stalling or running poorly in different conditions.

- Features like **launch control** (helpful for quick starts on steep climbs) and **adjustable traction control** (TC/FC modes) make the bike more manageable for riders of varying skill levels.

6. **Aftermarket Support and Customization**

- The KTM 350 SX-F has a **strong aftermarket presence**, with a wide range of parts available for upgrades (e.g., exhausts, clutch kits, suspension tuning). This makes it easy to modify the bike to suit personal preferences.

- The **WP XACT system** is highly tunable, allowing riders to optimize the suspension for their specific needs.

7. **Rider Comfort and Ergonomics**

- The **upright riding position** is more comfortable for long trail rides compared to aggressive motocross bikes. The **ergonomic handlebars and footpegs** reduce fatigue on extended outings.

- The **seat is reasonably comfortable** for its class, though some riders may prefer a firmer or more supportive option for aggressive riding.

8. **Value for Money**

- Compared to other high-performance trail bikes (e.g., Husqvarna, Yamaha, Suzuki), the KTM 350 SX-F offers **excellent value**. Its **suspension, power, and build quality** justify its price, especially for riders who want a bike that can handle both trail and light cross-country riding.

---

#### **Cons**

1. **Aggressive Riding Position**

- While the riding position is more upright than a full motocross bike, it is still **lean-forward and aggressive**, which may not suit riders who prefer a more relaxed, touring-like posture. This can lead to discomfort on very long rides.

2. **Limited Storage**

- The bike has **minimal storage options** only a small top tube bag or a rear rack can be fitted, which may be inconvenient for long-distance enduro rides where carrying extra gear is necessary.

3. **Maintenance Requirements**

- Like all KTM bikes, the 350 SX-F requires **regular maintenance** to keep it running optimally. The **WP XACT suspension** is advanced but sensitive to dirt and debris, so riders must clean and service it frequently to prevent wear.

- The **fuel-injected engine** is reliable but can be finicky if not properly tuned or if low-quality fuel is used.

4. **Weight Distribution**

- While the bike is lightweight, the **engine and suspension setup** can make it feel slightly **top-heavy** in tight corners or at low speeds, requiring careful handling from inexperienced riders.

5. **Noise and Vibration**

- The **naked exhaust and high-revving engine** make the bike loud, which may not be ideal for riders who prefer a quieter experience.

- Some riders report **excessive vibration at high speeds**, particularly on rough terrain, though this can be mitigated with proper suspension tuning.

6. **Learning Curve for Beginners**

- The **power delivery and suspension sensitivity** mean that the 350 SX-F is **not the best beginner bike**. New riders may struggle with the bike s responsiveness, especially on technical trails or in tight corners.

7. **Resale Value**

- KTM bikes generally hold their value well, but the **350 SX-F s niche appeal** (cross-country/trail riding) means it may not retain value as quickly as more mainstream bikes like the 250 SX-F or 450 SX-F.

8. **Limited Off-Road Comfort**

- While the suspension is excellent, the bike is **not designed for extreme off-road comfort**. Riders expecting a plush, cushioned ride (like on a dual-sport or adventure bike) may find it too firm.

---

### **Conclusion**

The **KTM 350 SX-F 2021 (WP XACT XTRIG, Rear Shock, 125-450 TC/FC)** is an **exceptionally capable trail and cross-country bike**, offering a **perfect balance of power, agility, and suspension quality**. It excels in **technical terrain, enduro riding, and light motocross**, making it a top choice for riders who demand performance without sacrificing comfort.

However, it is **not ideal for beginners** due to its aggressive nature and sensitivity, nor is it the best for **long-distance touring or extreme comfort**. It also lacks storage options and requires **regular maintenance** to perform at its best.

If you are a **skilled rider** looking for a **versatile, high-performance trail bike** that can handle everything from tight singletrack to fast cross-country riding, the 350 SX-F is an **excellent choice**. For **casual riders, beginners, or those prioritizing comfort over performance**, a more forgiving bike (such as a 250 SX-F or a dual-sport) may be a better fit.

---

### **Final Recommendation**

- You are an **intermediate to advanced rider** seeking a **high-performance trail/cross-country bike**.

- You value **agility, power, and advanced suspension** (WP XACT XTRIG).

- You plan to ride on **technical trails, enduro courses, or light motocross**.

- You are willing to **invest in maintenance and potential upgrades** to maximize performance.

- You are a **beginner rider** and prefer a more forgiving bike (e.g., 250 SX-F or Husqvarna TE 300i).

- You prioritize **comfort and storage** over raw performance (e.g., Yamaha T n r 700 or Royal Enfield Himalayan).

- You ride mostly **paved roads or smooth trails** and want a more relaxed riding position.

**Overall, the 350 SX-F is one of the best trail bikes in its class**, and if it fits your riding style and experience level, it will be a **rewarding and enjoyable purchase**.

Details:

Check bike fitment for all years item fits. Please reach out before purchasing Item shows signs of normal wear. Was set up by solid performance for 175lb MC. Xtrig reload adjuster installed.

In good working condition w/ low hours no leaks. 2021 Ktm 350SXF rear shock. Will come as shown in pictures.

part #: 18187u5701 prices

• $69.95-$129.97

specifications cyclevintagee:

• for models: 350sxf, Tc
• for makes: Ktm
• for years: 2021
• mpn: 18187u5701
• part type: Shock Suspension
• placement on vehicle: Rear

payments cyclevintagee:

• other
• credit card: Diners-club
• wallet: Apple-pay

shipping cyclevintagee:

• cost: $0.00
• type: Fixed
• class: Standard
• service: Standard
• transit: 3-7 Days

offer cyclevintagee:

• sold: 0
• availability: In Stock
• started: March 25, 2026
• options: Ship-to-home
• quantity: 1

returns cyclevintagee:

• time: 30 Days
• paid by: Buyer
• policy: Returns Accepted

seller cyclevintagee:

• rating: 99.9%
• city: Joppa, Maryland
• # reviews: 1640

general cyclevintagee:

• Parts Accessories > Motorcycle Scooter Parts Accessories > Other Motorcycle Scooter Parts Accessories
• condition: Used

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