Overview
The Firma 2100Kv Sensored brushless motor is a great choice for 1/10 scale crawlers, rock racers, and trailers running on 2S – 3S LiPo power. Featuring a low cog 4-pole 8-magnet rotor design, CNC machined aluminum housing, insulated high purity copper windings, high-quality alloy steel 3.175mm (1/8") output shaft, and precision bearings for high durability and smooth rotation. Preinstalled with 4mm gold plated bullet connectors for easy installation. The Spektrum FIRMA 60A Sensored Brushless Smart Crawler ESC is required.
Features
- Excellent upgrade for 540 brushed motors with the same diameter and mounting pattern (vehicle must accept pinions with a 1/8" mm bore)
- Perfect balance of speed and torque, great for trail and scale crawling applications
- High-quality 4-pole sintered rotor
- Polarity protection - magnetic encoder inside the motor guarantees consistency between three phases' signals and always outputs precise signals indicated by rotor position. When installing simply match wire color to esc connectors
- 4mm gold plated bullet connectors
- Waterproof sensor wire with locking plug and gasket
- High-quality construction with precision ball bearings and hardened steel 1/8" shaft
Overview
The Spektrum Firma 2100Kv Sensored brushless motor is an excellent choice for RC enthusiasts in the UK looking to upgrade their 1/10 scale crawlers, rock racers, and trailers. This premium brushless RC motor is specifically designed for 2S–3S LiPo power systems, making it perfect for those running on standard lithium polymer batteries. Whether you're a seasoned crawler competitor or someone discovering brushless RC vehicles for the first time, this motor delivers the perfect balance of speed and torque that trail and scale crawling applications demand.
Built with professional-grade engineering, the Firma 2100Kv features a sophisticated low cog 4-pole 8-magnet rotor design combined with a CNC machined aluminium housing that ensures durability and precision. The motor is constructed with insulated high purity copper windings that deliver consistent power delivery, whilst the high-quality alloy steel 3.175mm (1/8 inch) output shaft and precision ball bearings guarantee smooth rotation and extended service life. This brushless RC motor comes preinstalled with 3.5mm gold plated bullet connectors, allowing for straightforward installation directly into your vehicle without requiring additional modifications or adapters.
What truly sets this sensored brushless motor apart is its integration of polarity protection technology via a magnetic encoder housed inside the motor itself. This advanced feature ensures consistency between the three phases' signals and always outputs precise signals indicated by rotor position, delivering reliability that dedicated crawler enthusiasts expect. The waterproof sensor wire with locking plug and gasket provides additional protection against the elements, making this an ideal upgrade for serious trail runners and scale crawling competitors across the UK.
Key Features
- Excellent 540 brushed motor upgrade — This sensored brushless motor maintains the same diameter and mounting pattern as 540 brushed motors, allowing it to serve as a direct drop-in upgrade for existing RC crawlers and rock racers (provided your vehicle accepts pinions with a 1/8 inch bore). This compatibility means you can significantly enhance your vehicle's performance without requiring extensive chassis modifications or custom mounting solutions.
- Perfect balance of speed and torque — The 2100Kv rating combined with the advanced 4-pole rotor design creates an ideal power curve for trail and scale crawling applications, delivering responsive acceleration whilst maintaining the low-end grunt necessary for obstacle navigation and hill climbing that defines the crawling experience.
- High-quality 4-pole sintered rotor — The sintered rotor construction provides superior durability and magnetic consistency compared to standard rotor designs, ensuring reliable performance across countless hours of trail running and competitive crawling events without degradation of power output or responsiveness.
- Polarity protection with magnetic encoder — The integrated magnetic encoder guarantees consistency between the three motor phases' signals, always outputting precise signals indicated by rotor position. This technology ensures that your ESC receives accurate commutation data for seamless operation, critical for smooth power delivery in demanding off-road environments.
- CNC machined aluminium housing — Precision CNC machining creates a robust aluminium housing that dissipates heat effectively whilst maintaining tight tolerances essential for consistent performance. The aluminium construction provides an excellent strength-to-weight ratio, keeping your vehicle responsive whilst delivering long-lasting durability.
- Insulated high purity copper windings — The use of high purity copper reduces electrical resistance and improves power efficiency, translating to longer run times and more consistent performance throughout your crawling sessions. The insulation protects against electrical faults and ensures safe operation even in wet trail conditions.
- High-quality alloy steel output shaft — The hardened steel 1/8 inch (3.175mm) shaft resists bending and wear, crucial for maintaining alignment and preventing failure under the demanding torque loads experienced during rock crawling and obstacle navigation.
- Precision ball bearings — High-quality ball bearings reduce friction and ensure smooth, quiet rotation, contributing to both performance and longevity. These precision components allow the motor to spin freely whilst supporting the radial and axial loads placed upon it during aggressive crawling.
- 3.5mm gold plated bullet connectors — The pre-installed 3.5mm connectors feature gold plating to resist oxidation and ensure reliable electrical contact, reducing resistance and power loss whilst simplifying installation into compatible ESCs and battery systems.
- Waterproof sensor wire with locking plug — The integrated waterproof sensor wire with locking plug and gasket provides protection against mud, water, and debris encountered on technical trail sections, ensuring consistent sensored performance regardless of weather conditions or terrain challenges.
- Sensored FOC capability — This motor supports Field-Oriented Control (FOC) operation through its sensored architecture, enabling advanced ESCs to optimise commutation and deliver smoother, more efficient power delivery compared to traditional sensored brushless motors.
Technical Performance
The Spektrum Firma 2100Kv Sensored brushless motor represents a significant upgrade for 1/10 scale RC crawlers and rock racers operating on 2S–3S LiPo battery systems (7.4V to 11.1V input voltage range). At 2100Kv, this motor delivers approximately 2100 RPM per volt of input, providing a carefully calibrated speed curve that prioritises torque and control over raw velocity—essential characteristics for navigating technical terrain, climbing steep gradients, and maintaining traction on challenging surfaces. The motor's 4-pole architecture with 8-magnet rotor design creates excellent low-end response and smooth power delivery throughout the RPM range, critical for crawling applications where precision throttle control determines success on rocks and obstacles. Built to withstand maximum continuous current of 38A, this motor pairs perfectly with the Spektrum Firma 60A Sensored Brushless Smart Crawler ESC, a recommended speed control that leverages the motor's sensored capabilities for optimal performance. The combination of CNC machined aluminium housing, precision ball bearings, and high purity copper windings ensures this motor will deliver consistent performance across countless crawling sessions, whether you're competing in organised events or enjoying weekend trail runs across the UK's diverse terrain. The motor's water-resistant design makes it suitable for muddy trails and wet conditions, though proper maintenance remains essential for longevity. Measuring 1.42 inches (36mm) in outer diameter and 2.27 inches (58mm) in length, the Firma 2100Kv maintains the compact form factor necessary for fitting into standard 1/10 scale crawler chassis whilst housing professional-grade internal components.
What's in the Box
- SPM Firma 2100Kv Brushless Sensored Crawler Motor
- Pre-installed 3.5mm gold plated bullet connectors
- Waterproof sensor wire with locking plug and gasket
What You Need to Complete
- Spektrum Firma 60A Sensored Brushless Smart Crawler ESC (required for operation)
- 2S–3S LiPo battery pack (7.4V–11.1V)
- Battery charger compatible with LiPo cells
- RC transmitter and receiver compatible with your crawler chassis
- Pinion gear with 1/8 inch bore (if upgrading from brushed motor setup)
Frequently Asked Questions
- Is the Spektrum Firma 2100Kv motor suitable for beginners getting into brushless RC crawlers? — Yes, this motor is an excellent choice for beginners upgrading from brushed motors. The sensored architecture provides smooth, consistent performance that's forgiving to new users, whilst the 2100Kv rating prioritises torque and control over speed, making it easier to learn proper crawling technique. The pre-installed connectors and straightforward installation also reduce setup complexity.
- What battery does this Firma motor need, and how long will it run? — The Firma 2100Kv motor requires 2S or 3S LiPo batteries, providing input voltage between 7.4V (2S) and 11.1V (3S). A 3S battery will deliver more power but faster consumption, whilst 2S provides longer runtime at slightly reduced performance. Typical runtime depends on your specific battery capacity and driving style, but most users report 20-45 minutes per charge with standard crawler batteries.
- Can I upgrade my existing brushed motor crawler with this Firma sensored motor? — Absolutely. This motor maintains the same diameter and mounting pattern as standard 540 brushed motors, making it a direct replacement upgrade (provided your vehicle accepts pinions with a 1/8 inch bore). You'll need to ensure your ESC is compatible—the Spektrum Firma 60A Sensored ESC is the recommended pairing.
- What makes this motor better than brushed alternatives for crawling? — Brushless motors offer superior efficiency, less maintenance (no brush wear), and smoother power delivery compared to brushed motors. The sensored architecture provides precise commutation feedback, ensuring consistent performance and enabling advanced features like FOC operation for silky-smooth torque delivery—critical for technical rock crawling where smooth throttle response determines whether you clear an obstacle or get stuck.
- Is the Firma 2100Kv waterproof for muddy trail conditions? — The motor features water-resistant construction with a waterproof sensor wire, making it suitable for wet and muddy trail conditions. However, complete waterproofing cannot be guaranteed, so rinsing the motor after muddy sessions and allowing it to dry is recommended to extend lifespan and maintain performance.
- What ESC do I need to run this sensored brushless motor? — The Spektrum Firma 60A Sensored Brushless Smart Crawler ESC is the required and recommended speed control. This ESC is specifically designed to work seamlessly with this motor's sensored system, providing optimal commutation and performance optimisation through FOC capability.
- How does the sensored design improve performance compared to sensorless brushless motors? — Sensored motors use hall effect sensors (in this case, a magnetic encoder) to provide precise rotor position feedback to the ESC. This enables accurate commutation timing at all speeds, resulting in smoother acceleration, better low-end torque response, and improved efficiency—all characteristics highly valued in crawler applications where smooth, controllable power is paramount.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the SPM Firma 2100Kv Brushless Sensored Crawler Motor M-SPMXSM3001 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
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