Axial’s New 21RR-1 Engine, Rock Crawler Speed Control And 2.4GHz Radio

Axial’s New 21RR-1 Engine, Rock Crawler Speed Control And 2.4GHz Radio

Axial releases a new nitro engine (21RR-1) for the backyard basher on a budget, a new speed control developed in partnership with Castle Creations for rock crawlers, and adds a 2 channel 2.4ghz radio to its lineup.

Axial .21RR-1 Engine

This is Axial’s first .21 Cubic Inch / 3.47cc nitro engine to complement the reputable RR Series of ABC Designed Engines* designed for the racing enthusiast, from buggy basher to weekend race warrior. Starting with looks alone, this engine stands out especially with the tech looking, “murdered out” – cross drilled head and crankcase. *ABC construction: Aluminum piston – Brass cylinder liner – Chrome plated.

This is not just a cool looking engine, nor is it “just” an addition to the Axial RR Performance Series of engines. The Axial 21RR-1 Engine has vast improvements with such features as a rock solid 2-needle carburetor, balanced crankshaft, 7-port piston cylinder sleeve and all new designed crankcase with emphasis on strength and weight reduction.

The Axial 21RR-1 carburetor has the stealth blacked out looks built with simplistic 2-needle design for ease of use. Color coded aluminum venturis in increments of 6.5mm, 7.0mm and 8.0mm are supplied to use in conjunction with the stock carburetor [9.0mm inlet] allowing for a wide range of airflow velocity tuning capabilities. Fully adjustable fuel valves and carb-linkage allow this carburetor to work on various engine applications. Another “performance-look” feature is the visual markings on the carburetor indicating 1/16th increments allowing for an “easy to adjust” air-fuel needle.

The heart of engine performance is in the piston cylinder sleeve. Axial delivers the highest level of quality through the ABC Engine Design with brass cylinder sleeve construction that is dimensionally stable during heat cycle process aided by chrome plating for both durability and precise compression. The brass cylinder sleeve houses a CAD designed CNC precision cut 7-port design with performance and torque in mind. The aluminum piston has a very high content level of silica for high-performance stability, of which give the piston its characteristically textured look.

While the piston and sleeve may be the heart of an engine, the crank takes the vertical power from the piston and transfers that “life” in the horizontal direction to the wheels. The Axial 21RR-1 crankshaft is precision machined and counterbalanced with brass slugs to provide a smoother running engine, reducing vibration and delivering more “usable” power. The intake portion of the crankshaft uses port flow epoxy for a tuned flow of air and gas into the piston for the maximum performance in the smoothest controlled manor.

While power-to-weight ratio is the lifeblood of performance, Axial has painstakingly redesigned a precision machined crankcase to maintain strength and durability while going on a diet through strategic case design. With its overall performance in mind, the fins that are located around the cylinder wall and cylinder head or heat sink have been cross-drilled to reduce top end weight, while adding a bit of that bling factor. The cross drilling process also gives the Axial 21RR-1 engine additional surface area which aids in cooling and reduces heat soak, the culprit of engine performance degradation.

Axial engines are dyno tested to ensure the highest level of performance possible. We use the highest quality materials and the latest CAD and CNC techniques to set the maximum level of quality possible at roughly half the cost. The Axial 21RR-1 engine is aimed to provide the perfect balance between performance and price to deliver the top overall value for the enthusiast that likes to run hard and spend a little. If you are looking for “the best bang for the buck nitro engine” the Axial 21RR-1 is for you!


  • Precision machined all new crankcase was designed to be lightweight but still maintain strength and durability
  • Cross drilled fins around cylinder wall provide better cooling efficiency while reducing weight up high
  • Black coated to signify its overall look

Cooling Head

  • Perfectly sized to provide proper cooling while lowering the weight
  • Cross drilled fins help to further the weight reduction and lower the center of gravity

Button Head

  • Fitted with a standard type glow plug button head makes it easier to tune
  • Turbo Button head available as an option

Piston/Sleeve/Connecting Rod

  • True ABC constructions adds to a longer engine life
  • 7 port engine sleeve design aids in the performance and torque of the engine
  • Piston and sleeve materials were specifically selected to maintain the proper tolerances throughout the heat cycle range
  • Lightweight aluminum connecting rod with brass bushings


  • Precision machined crankshaft has been counterbalanced with brass slugs to provide a smoother running engine and reduce vibrations
  • Silicone putty is used on the intake portion to smooth the gas flow and provide better engine performance and response


  • All new 2 needle carburetor design makes it easier than ever to tune
  • Markings on the idle, low speed needle, and high speed needle makes it easy to make adjustments in 1/16th turn increments
  • Fully adjustable fuel valves as well as carburetor linkage makes it easy to install into any platform
  • Precision machined aluminum venturis are included to aid in smoother gas flow
  • Aluminum venturis also aid in tuning the motor for different tracks and environments to aid in longer run times
  • Bolt-in replacement engine for any .21+ engine mount


Size: .21 cubic inch/3.47cc
Maximum RPM: 40,000
Bore: 15.9mm
Stroke: 17.5mm
Construction: ABC
Heat-sink Head: Black Anodized
Carburetor: 9.0mm Composite Slide Carburetor (includes 8.0, 7 & 6.5mm aluminum venturis)
Carburetor Adjustments: 2 Needle, Flush Settings
Case: Black Aluminum, Rear Exhaust
Connecting Rod: Dual Bushing
Sleeve: 7 port
Starting system: Bumpstart
Recommended Glow Plug: Standard Long Glow Plug
Weight: 338.5g/11.94oz

AX00300 Axial .21RR-1 Engine (Black) $215.00

Axial AE-2 Forward Reverse ESC w Drag Brake

  • Developed in partnership with Castle Creations
  • Programmable using the Castle Link™
  • LiPo cutoff set on from factory
  • Easy connect bullet connectors allow you to connect to Axial motors without soldering
  • Tamiya style plug connector allows you to use any off the shelf batteries
  • Instant forward/reverse and drag brake is perfectly suited for rock crawling


Input Voltage: 6 cell Ni/2S LiPo
Size: 43×31.5mm (1.7”x1.24”)
Weight: 45g/1.6oz
Motor Limit: 19T
On-Resistance FET: .0018
Rated/Peak Current: 106A Peak
Braking Current: 106A Peak
BEC Voltage/A: 5.0V/2.0A Peak
PWM Frequency: 6 KHZ

AX24259 Axial AE-2 Forward/Reverse ESC w/Drag Brake $90.00

Axial 2.4Ghz 2 Channel Radio System

  • 2.4Ghz system means no interference from other RC vehicles in the area
  • 2 Channel system with reversing switches and trim settings

AX24204 Axial 2.4Ghz Radio System (2 Channel) $90.00

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Updated: July 20, 2015 — 2:33 PM
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