Overview
The Losi 1/4 Promoto-SM FXR Supermoto Motorcycle RTR Basic is the most authentic supermoto RC motorcycle experience ever offered in the radio-control market. This ready-to-run brushless RC motorcycle brings genuine supermoto styling and performance to on-road surfaces, making it the ideal choice for RC enthusiasts in the UK seeking a thrilling alternative to traditional RC cars and trucks. Whether you're exploring RC hobbies for the first time or you're a seasoned competitor, the Promoto-SM delivers an unmatched blend of realistic handling, stunning scale detail, and cutting-edge technology that transforms how you experience RC motorcycling.
Powering off the line, speeding down straights, and leaning through curves and turns, a unique harmony develops between you and the bike. The two intuitively become one. Despite its power, the two-wheeler feels light and nimble as it reacts instantly to your cues—as if it's simply an extension of you. That's how it feels to drive a Losi Promoto RC motorcycle. Following the breakthrough success of the Promoto-MX dirt bike, Losi has engineered the Promoto-SM specifically for on-road racing enthusiasts who demand authenticity, performance and style. This ready-to-run RC bike is particularly well-suited for concrete, asphalt, blacktop, and other hard surfaces found at neighbourhood streets, local parks, and parking lots throughout the UK.
The Promoto-SM represents the culmination of years of development, combining patent-pending Spektrum MS6X technology with innovative mechanical engineering inspired by full-size supermoto motorcycles. Key differences from the Promoto-MX dirt bike include new Pro-Line Racing OE (Original Equipment) supermoto street tyres on smaller, realistic wheels, a more powerful front brake caliper with improved stopping power, and revised lean bar wheels that reduce noise and deliver superior traction on hard surfaces. The Promoto-SM can lean farther than its dirt bike counterpart, and with its officially licensed FXR graphics and authentic rider gear, this brushless RC motorcycle looks like a true supermoto racer ready for aggressive on-road action.
Key Features
- Patent-Pending Spektrum MS6X Technology — The included Spektrum DX3PM transmitter and SR6300PM receiver combine with exclusive MS6X technology to deliver unprecedented control and balance at high or low speeds, allowing you to maintain stability whilst maneuvering over concrete, asphalt, blacktop and other hard surfaces with confidence.
- Powerful Brushless System with 40+ mph Top Speed — Equipped with a Spektrum Firma 3652 3800Kv 4-pole brushless motor paired with an 85A brushless smart electronic speed control, the Promoto-SM delivers massive acceleration and thrilling top speeds on a 2S LiPo battery, giving you the performance needed for serious on-road racing.
- Frame-Integrated High-RPM Flywheel with Gyroscopic Stabilisation — A heavy steel flywheel mounted as low and as far forward as possible in the frame spins at over 22,000 rpm with the motor to create powerful gyroscopic force, enabling unparalleled stability, improved jumping, quick changes of direction, and unprecedented performance accuracy that no other RC motorcycle can match.
- Three Intelligent Drive Modes — Toggle between Dirt Mode (pitch protection), Street Mode (rapid throttle clipping), and Wheelie Control (unlimited wheelie capability) on the fly using the DX3PM transmitter's A/B rocker switch, allowing you to adapt instantly to different riding conditions and surfaces.
- Updated Lean Bar System with Bearings — The repositioned lean bar can lean farther than the Promoto-MX counterpart, and new rubber lean bar tyres mounted on bearings reduce noise whilst offering superior traction on hard surfaces, with adjustable stops for dialling in the bike to any surface or grip level.
- Advanced Front Brake System — A new, more powerful front brake caliper with floating piston and metal injection moulded piston shaft applies larger pressure area to the brake pad, delivering shorter stopping distances and more consistent braking operation, whilst an innovative dual disc braking system cuts stopping distance in half compared to rear-only braking.
- Professional-Grade Suspension Geometry — Losi's product development team studied full-size motorcycle suspension geometry to deliver the same terrain-handling characteristics as real bikes, with a rising rate rear suspension that starts soft around ride height for smooth handling and superior grip, then becomes firmer as it compresses to prevent bottoming out during landings.
- Innovative Front Fork Design — The completely new front fork features an internal spring and dampener that can be tuned by changing silicone dampening fluid, allows ride height adjustment using spacers, and is mounted with counter-wound upper and lower springs for realistic and responsive handling that mirrors full-size motorcycle forks.
- Fluid-Filled Head Damping — A key development for the Promoto platform is a fluid-filled friction chamber between the upper and lower head tube bearings, filled with heavy 500,000cSt fluid that dampens the servo saver and controls any possible head shake during aggressive cornering and high-speed manoeuvres.
- Sophisticated Servo Saver System — Stiff circular springs captured by bearing-mounted composite plates provide consistency in steering with protective give to safeguard your servo, whilst dramatically improving performance during wheelies, jump landings, power slides and front-end impacts.
- Officially Licensed FXR Graphics and Authentic Styling — The Promoto-SM features distinctive visual details including hand guards, shortened front fender, and officially licensed FXR graphics that replicate full-size supermoto racing bikes, combined with a realistic rider figure in authentic riding gear that looks ready for aggressive on-road action.
- Pro-Line Racing OE Supermoto Street Tyres — Outfitted with new Pro-Line Racing OE (Original Equipment) supermoto street tyres designed specifically for the unique wear and traction requirements of supermoto-style road racing, complementing the bike's scale looks whilst delivering responsive handling on hard surfaces.
- True-Spoke Wheels with Realistic Design — Durable, realistic true-spoke wheels are smaller than the Promoto-MX in keeping with the design of real on-road motorcycles, providing authentic supermoto styling without compromising durability for RC racing applications.
- Collapsible Front Crash Structure — The front crash structure remains rigid during normal running but compresses until the front tyre bottoms into the chassis frame during impacts, protecting the front fork tubes from bending and keeping them safe and true for consistent performance through rough corners and crashes.
- Hinged Elastomer-Sprung Rear Fender — During wheelies, the hinged rear fender deflects out of the way to expose a durable nylon rear bumper underneath, substantially increasing the durability of the rear fender and allowing you to perform extended wheelies without damage.
- Chain Drive with Dual Disc Performance Slipper Clutch — A sophisticated chain drive system with dual disc performance slipper clutch delivers smooth power delivery and prevents wheel hop during hard acceleration, maintaining traction on slippery surfaces whilst providing the responsive feel of a real motorcycle transmission.
- Protective Composite Skid Plates — Moulded composite skid plates line the front and bottom of the Promoto-SM chassis, offering protection during crashes and keeping debris away from the chassis to protect the electronics mounted inside, extending the lifespan of your ready-to-run investment.
- Dual Twin Aluminium Chassis Plates — Twin aluminium chassis plates house and protect all electronics whilst giving the frame the rigidity and durability required for harsh impacts, and they help create the Promoto-SM's realistically narrow appearance that mimics full-size supermoto motorcycles.
- Convenient Maintenance and Starting Stands — The included display and maintenance stand is modelled after a real bike stand with graphics and features a keying system to keep the bike balanced when parked, whilst a separate hands-free starting stand cradles the rear tyre and holds the bike upright and ready for gate-style starts.
- Spektrum Smart Battery Technology Integration — LED indicators on the DX3PM transmitter show remaining capacity of Spektrum Smart batteries at a glance, and Smart technology allows automatic charging requirements to upload from the battery's memory microchip to a compatible Spektrum Smart charger for safe, simplified charging.
- Standard 2S LiPo Battery Compatibility — The Promoto-SM's compact narrow chassis accommodates a full-size standard 2S hardcase LiPo battery within the rider's seat area, allowing convenient, quick battery changes without requiring special shorty batteries, so you're back racing in seconds.
Technical Performance
The Losi Promoto-SM RTR Basic delivers genuine high-performance brushless RC racing on hard surfaces with specifications and engineering that rival full-size motorcycle technology. Powered by a Spektrum Firma 3652 3800Kv 4-pole brushless motor controlled by a Spektrum Firma 85A brushless smart electronic speed control, this ready-to-run RC motorcycle achieves thrilling top speeds exceeding 40 mph on a 2S 7.4V LiPo battery. The motor's high KV rating combined with the low-mounted, high-RPM flywheel spinning at over 22,000 rpm creates extraordinary gyroscopic stabilisation force that enables the Promoto-SM to maintain balance during aggressive cornering, rapid direction changes, and complex manoeuvres that would destabilise conventional RC motorcycles. The patent-pending Spektrum MS6X technology working in harmony with the innovative mechanical engineering means drivers of this brushless RC motorcycle experience unmatched control authority across the entire speed range, whether you're executing tight cornering on neighbourhood streets or pushing maximum velocity down local park roads. The chassis utilises twin aluminium plates for exceptional rigidity and durability, whilst the rising rate rear suspension with oil-filled coil-over shock absorber and innovative front fork with internal spring and dampener provide suspension geometry scientifically modelled on full-size motorcycle designs. The brake system features dual disc performance with an upgraded front caliper and floating piston that cuts stopping distance in half compared to rear-only braking systems, giving you confidence and control during emergency stops and race conditions. With dimensions of 504 mm length, 259 mm width, and 424 mm height, weighing 3540 grams, the Promoto-SM achieves realistic 1/4 scale proportions whilst maintaining the compact footprint required for neighbourhood and park racing throughout the UK. The intelligent electronic control system offers three preprogrammed drive modes accessible via the Spektrum DX3PM transmitter—Dirt Mode for obstacle approach with wheelie prevention, Street Mode for maximum acceleration, and Wheelie Control for unlimited wheelie capability—allowing you to optimise performance on any surface without reprogramming. Spektrum Smart battery technology integration provides real-time telemetry capabilities and automatic charging profile detection, simplifying battery management whilst maximising safety and battery lifespan during frequent racing sessions.
What's in the Box
- Losi Promoto-SM 1/4 Supermoto Motorcycle RTR FXR (Fully Assembled)
- Spektrum Smart DX3PM Transmitter with three preprogrammed drive modes
- Spektrum 6-Channel DSMR Promoto Receiver (SR6300PM)
- Four AA Transmitter Batteries
- Bike Display and Maintenance Stand with keying system
- Hands-Free Starting Stand with rear tyre cradle
- Product Manual with full assembly and tuning guidance
- Quick Start Guide for rapid setup
- Chain Lubricant
- Fork and Shock Tuning Tools for suspension customisation
What You Need to Complete
- One 2S 7.4V 5000mAh LiPo battery with EC5 or IC5 connector (sold separately)
- Compatible LiPo battery charger, preferably a Spektrum Smart charger for automatic profile detection (sold separately)
Frequently Asked Questions
- Is the Losi Promoto-SM suitable for RC beginners or only experienced riders? — The Promoto-SM is designed to be accessible to riders of various skill levels. Whilst the sophisticated technology and performance capabilities appeal to experienced RC enthusiasts, the three intelligent drive modes (Dirt, Street, and Wheelie Control) allow beginners to start in Street Mode with throttle clipping for stability, then progressively challenge themselves as they develop skills. The hands-free starting stand, included bike stand, and realistic handling feedback make learning intuitive, though the 40+ mph top speed means you should have some RC experience before operating at maximum velocity.
- What makes the Promoto-SM different from the Promoto-MX dirt bike? — The Promoto-SM is engineered specifically for on-road racing on asphalt, concrete, and blacktop surfaces, whereas the Promoto-MX is designed for dirt and off-road terrain. Key differences include Pro-Line Racing OE supermoto street tyres on smaller wheels (compared to off-road tyres), an upgraded and more powerful front brake caliper, repositioned lean bars that allow greater lean angles, revised lean bar wheels with bearings that reduce noise and improve hard-surface traction, shortened front fender for supermoto styling, and officially licensed FXR graphics. Both share the same innovative flywheel, Spektrum MS6X technology, and patent-pending mechanical systems.
- What battery does the Promoto-SM require and how long does it run? — The Promoto-SM requires a 2S 7.4V LiPo battery with either an EC5 or IC5 connector (sold separately). The specifications indicate 5000mAh capacity is recommended. Runtime varies depending on your driving style, terrain, and specific battery capacity, but a full 5000mAh 2S battery typically provides 15-25 minutes of continuous running at moderate speeds, with shorter runtimes during full-throttle racing. Spektrum Smart batteries work seamlessly with the included DX3PM transmitter for real-time capacity monitoring.
- What is the top speed and does it work on different surfaces? — The Promoto-SM achieves 40+ mph top speeds on a 2S LiPo battery, making it one of the fastest RC motorcycles available. The bike is specifically optimised for hard surfaces including concrete, asphalt, blacktop, and sealed roads found at neighbourhood streets, local parks, and parking lots. The three intelligent drive modes allow you to adjust performance: Street Mode emphasises traction and throttle control for maximum grip, Wheelie Control allows unlimited wheelies on smooth surfaces, and Dirt Mode includes pitch-up tolerance for approaching small obstacles. The Pro-Line Racing OE supermoto street tyres are designed specifically for supermoto-style road racing, making the Promoto-SM the definitive on-road RC motorcycle choice.
- Is the Promoto-SM waterproof and can it handle wet conditions? — Whilst the manufacturer specifications do not explicitly state an IP waterproofing rating, the Promoto-SM features sealed electronics housed within the twin aluminium chassis plates, skid plate protection, and air vents that can be closed to prevent debris ingestion. The sophisticated servo saver system and fluid-filled head damping chamber offer additional protection. However, because this is an advanced electronic system, it is recommended to avoid intentional water exposure and to dry the bike promptly if exposed to light rain or wet surfaces.
- What radio system and transmitter does it use? — The Promoto-SM includes a Spektrum Smart DX3PM transmitter (DSMR protocol) and a Spektrum 6-Channel DSMR Promoto Receiver (SR6300PM). The DX3PM features an A/B rocker switch to toggle between three preprogrammed drive modes (Dirt, Street, and Wheelie Control) on the fly, LED battery indicators for Spektrum Smart battery capacity monitoring, and integration with Spektrum Smart technology for automatic charging profile detection. The system utilises Spektrum's reliable 2.4 GHz DSMR frequency with 6-channel capability and is fully compatible with all Promoto-series motorcycles.
- Can you upgrade the transmitter for additional telemetry information? — Yes, the Promoto-SM works with additional Spektrum transmitters. By upgrading to a Spektrum DX5C or DX5 Pro transmitter, you unlock real-time telemetry including speed, RPM, amp draw, and ESC temperature monitoring, providing detailed performance data for race analysis and tuning optimisation. The included DX3PM remains capable for standard operation and drive mode selection.
- What servos are included and what are their specifications? — The Promoto-SM includes two servos: a Spektrum S620PM Metal Gear Servo for steering control and a Spektrum SX108PM Micro Servo for front brake operation. The metal gear steering servo provides the stiffness required for the demanding servo saver system, whilst the micro servo offers precise brake modulation. Both are Spektrum digital servos with the precision and durability expected in a professional-grade RC motorcycle system.
- How do the lean bars work and why are they important? — The innovative lean bar system is crucial to the Promoto-SM's realistic motorcycle handling. Updated lean bar positioning allows the bike to lean farther than the Promoto-MX dirt bike counterpart, with new rubber lean bar tyres mounted on bearings that reduce noise and provide excellent traction on hard surfaces. Adjustable stops allow you to dial in travel for any surface or grip level. During crashes where the rear wheel retains traction, hitting the throttle causes the bike to stand upright and resume driving, often assisted by the lean bars. This system replicates how real motorcycles behave, making recovery intuitive and extending the lifespan of the bike through reduced impact damage.
- What is the difference between Street Mode and Wheelie Control? — Street Mode is the default performance setting designed for smooth, controlled on-road racing. When the bike begins to pitch up (front wheel lifting), the system quickly clips throttle output to bring the front tyre back to the ground, maximising acceleration whilst preventing unwanted wheelies. Wheelie Control removes this limitation, allowing you to hold extended wheelies all the way to top speed on smooth surfaces. You toggle between these modes (and Dirt Mode) using the DX3PM's A/B rocker switch without stopping, making it easy to adapt to track conditions on the fly.
- How does the rising rate rear suspension work? — The rising rate rear suspension is scientifically designed based on full-size motorcycle geometry. Around ride height, the suspension is relatively soft for smooth handling and superior grip on the road surface. As the suspension compresses deeper into travel (such as during jumps or hard landings), the spring rate increases progressively, providing greater preload and stiffness to prevent bottoming out. This dual-rate behaviour is tuned via the oil-filled coil-over shock absorber and can be further customised by adjusting oil viscosity using the included tuning tools, allowing you to optimise performance for your specific riding style and track conditions.
- Is assembly required or is it truly ready-to-run? — The Promoto-SM is fully assembled and ready to run (RTR). You only need to install four AA batteries in the DX3PM transmitter, add a charged 2S LiPo battery to the bike (sold separately), and you're ready to race. The included Quick Start Guide makes initial setup simple and straightforward, so you can be driving within minutes of unboxing.
- What is the warranty and where can I get technical support? — Warranty details vary by region; however, as an authorised Losi dealer, RC Model Shop provides genuine products backed by the manufacturer's warranty. The product manual and quick start guide provide comprehensive setup and tuning information, and detailed exploded view diagrams help with maintenance and parts identification. RC Model Shop's team of experienced RC enthusiasts is available to assist with technical questions and support.
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 LOS 1/4 Promoto-SM FXR Supermoto Motorcycle RTR Basic C-LOS-2272 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.
