Direct Drive Wheels: Everything You Need To Know

At MOZA Racing, we’ve been developing our high-technology direct drive wheelbases to deliver the most immersive sim racing experience possible. Our range of Direct Drive Wheels is designed to meet the needs of professional and enthusiast drivers alike.

From our innovative entry-level R3 to our flagship R21, each wheelbase is engineered to provide the highest fidelity force feedback quality and reliability.

In this article, we’ll explain what a direct drive wheel is, how they work and what makes our FFB (force feedback) the best direct drive wheel experience you’ll ever feel.

Image: Traxion.gg

How does a Direct Drive Wheel work?

The Core Concept: Direct Connection

The fundamental principle is in the name: direct drive. Unlike obsolete belt-driven or gear-driven wheels, a direct drive wheel connects the steering wheel directly to the motor shaft.

There are no intermediate belts, gears, or pulleys. This eliminates the “mushiness” and probable loss of detail that those systems introduce.

The Motor: The Key Component in the System

Direct drive wheels use powerful electric motors, typically servo motors. Our servo motors feature slanted-pole designs intended for precise control of position, and torque.

Servo motors are the most common type of motor found in high-end direct drive wheel systems. Regardless of the manufacturer, an encoder will always be a feature to precisely track the rotor’s position.

The encoder is a crucial component. It’s a sensor attached to the motor shaft that provides extremely precise information about the wheel’s rotational position. This data is sent to the motor controller, which uses it to:

Accurately apply force feedback: The controller knows exactly where the wheel is and can apply the correct amount of torque to simulate forces from the game.

Track wheel position for the game: The game needs to know the wheel’s position to translate it into steering input for the virtual car. The encoder provides this information with high precision.

We use very high-resolution encoders which allow for accurate position and input measurements.

The motor controller receives commands from your sim racing software and adjusts the current to the motor windings to achieve the desired force and position.

The Motor Controller

The motor controller is the “brain” of the direct drive system. It receives commands from the sim racing software via the Windows.Gaming.Input API (see documentation here) and translates them into electrical signals that drive the motor. It does this by:

Interpreting force feedback data: The game calculates the forces acting on your simulated car (tyre slip, road bumps, etc.) and sends this data to the wheel as force feedback commands. The controller interprets these commands.

Controlling motor torque: Based on the force feedback data and the wheel’s position (from the encoder), the controller adjusts the current flowing through the motor windings to produce the desired torque.

Managing motor safety: The controller also monitors the motor’s temperature, current, and other parameters to prevent damage.

The Software

The sim racing software is the source of the force feedback data. It calculates the physics of the virtual car and sends the appropriate forces to the wheel.

The software also receives the wheel position data from the encoder and uses it to control the virtual car’s steering.

Additionally, dedicated software, like Moza Pit House, is used to configure the wheel base itself.

Force Feedback Algorithms: The Fine Details

The way the force feedback data is translated into motor torque is determined by complex algorithms. We’ve written a proprietary algorithm called NexGen 3.0 Force Feedback so that our engineers can provide exquisite control over the quality of the force feedback you experience.

The NexGen 3.0 advanced algorithm eliminates swaying during straight-line driving and refines a sense of natural inertia of the vehicle. This creates a smoother and more realistic racing experience.

FFB algorithms take into account factors such as:

• Torque curves: How the motor’s torque output varies with current.
• Inertia: The resistance of the wheel to changes in rotation.
• Damping: Forces that oppose motion.
• Friction: Forces that resist sliding.

These algorithms are tuned by us to create that realistic and immersive driving feel.

Power Supply

Direct-drive wheels require a substantial power supply to drive the powerful motors. These are typically external power bricks. The R21 has a peak power output of 480 watts, so the power supply must be able to respond to high current demands for very long periods of time.

MOZA Racing Direct Drive Wheelbases

MOZA R21

The R21 wheelbase represents our most powerful direct drive technology, featuring a 21Nm peak torque output. The R21’s motor uses a 12-36 pole, slanted interior permanent magnet design with a carbon fibre rotor sleeve for thermal management.

This motor design, combined with a high-resolution encoder, delivers smooth and detailed force feedback for the most demanding sim racing applications.

Technical Specifications:

• Peak Torque: 21 Nm
• Peak Power: 480W
• Encoder Resolution: 262,144 PPR (18-bit)
• Operating Range: 0-350 RPM
• Dimensions: 327 x 170 x 130mm
• Weight: 8.9kg
• Housing: Aviation-grade aluminum alloy
• Input Voltage: 110V~220V AC —>36V DC
• USB Refresh Rate: 1000Hz

R21 Review

Moza R21 Review by Geek Street

If you like what you’ve read and you’re interested in joining the Moza ecosystem, go ahead and take a look at our full range of sim racing wheelbases and wheels in our store.

Happy racing!

MOZA R16

The R16 shares the same advanced motor technology as the R21, featuring the 12-36 pole slanted design and a carbon fibre rotor sleeve.

With 16Nm of peak torque, the R16 delivers exceptional force feedback detail while maintaining efficient thermal performance for extended racing sessions.

Technical Specifications:

• Peak Torque: 16 Nm
• Peak Power: 360W
• Encoder Resolution: 262,144 PPR (18-bit)
• Operating Range: 0-350 RPM
• Dimensions: 327 x 170 x 130mm
• Weight: 8.9kg
• Housing: Aviation-grade aluminum alloy
• Input Voltage: 110V~220V AC —>36V DC
• USB Refresh Rate: 1000Hz

R16 Review

R16 review by Lawrence Dusoswa

MOZA R12

The R12 wheelbase delivers 12Nm of peak torque through our direct drive servo motor with copper concentrate windings.

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This wheelbase incorporates our NexGen 3.0 Force Feedback algorithm for highly detailed force feedback effects while maintaining excellent thermal efficiency during extended use.

Technical Specifications:

• Peak Torque: 12 Nm
• Peak Power: 216W
• Housing Material: Aviation-grade aluminium alloy
• Dimensions: 225.87 x 156.68 x 123.99mm
• Weight: 7.5kg
• Input Voltage: 110V~220V AC —>36V DC
• USB Refresh Rate: 1000Hz
• Compatible with MOZA Quick Release system

R12 ReviewMoza R12 review by SIMRACINGCOCKPIT.gg

MOZA R9

The R9 delivers 9Nm of peak torque in a compact form factor. Using our direct drive servo motor technology with copper concentrate windings, the R9 provides precise force feedback and reliable, consistent FFB performance.

Technical Specifications:

• Peak Torque: 9 Nm
• Peak Power: 180W
• Housing Material: Aviation-grade aluminium alloy
• Dimensions: 240 x 157 x 124mm
• Weight: 5kg
• Input Voltage: 110V~220V AC —>36V DC
• USB Refresh Rate: 1000Hz
• Mounting: 4 holes on the bottom, optional table clamp

R9 Review

Moza R9 review by CK Sim Racing

MOZA R5

The R5 offers 5.5Nm of peak torque through our direct drive servo motor design.

This wheelbase provides excellent force feedback detail and smooth operation at a more accessible price point, making true direct drive technology available to more sim racers.

Technical Specifications:

• Peak Torque: 5.5 Nm
• Peak Power: 108W
• Housing Material: Aviation-grade aluminium alloy
• Dimensions: 200 x 150 x 120mm
• Weight: 4.5kg
• Input Voltage: 110V~220V AC —>36V DC
• USB Refresh Rate: 1000Hz
• Compatible with MOZA Quick Release system
  
  

Moza R5 Review

R5 review by SIMRACINGCOCKPIT.gg

MOZA R3

The R3 is our most accessible direct drive wheelbase, offering 3.9Nm of peak torque.

It’s the first MOZA Racing wheelbase to feature Xbox compatibility, making it perfect for sim racers wanting direct drive technology across multiple platforms.

Technical Specifications:

• Peak Torque: 3.9 Nm
• Peak Power: 84W
• Housing Material: Aviation-grade aluminium alloy
• Dimensions: 200 x 150 x 120mm
• Weight: 4kg
• Input Voltage: 110V~220V AC —>36V DC
• USB Refresh Rate: 1000Hz
• Platform Compatibility: PC & Xbox
• Compatible with MOZA Quick Release system

R3 Review

Moza R3 review by OC Racing