Simucube Direct Drive Wheels: Everything You Need to Know

For those sim racers looking for the realism and deep immersion associated with “high-end” simulation, direct drive wheel bases are the “go to” sim racing technology. That wasn’t always the case, however. In the beginning, direct drive wheels were only available to the technically minded hobbyist who was able to assemble a kit or possibly, even design a controller based on a MiGE motor. That has (of course) completely changed today.

When consumer orientated direct drive wheels first became available, Simucube were on the scene at the start (owing to industrial expertise from Granite Devices) with the Simucube 1. The Simucube 1 still needed reasonable technical ability, but suppliers quickly realised they could assemble these devices with their own branding and sell them to the public.

This period came to an end with the launch of the Simucube 2 series, which is a self-contained direct drive wheel system, with proprietary software called Simucube True Drive.

Today, we’re taking an in-depth look at what makes the Simucube 2 lineup so exceptional.

If you’re not sure of the terminology I’m using throughout the article, I’ve prepared a Glossary of Terms at the end to explain. Phrases like “Slew Rate” might be new to you – as it is to all of us at some point!

The Simucube 2 Lineup

The Simucube 2 series comprises of 3 models: The Sport, Pro, and Ultimate. Each variant features engineering grade servo motors and each offers features that cater to different performance requirements and to budgets.

The entry-level Simucube 2 Sport boasts an impressive 17 Nm of peak torque and a slew rate of 4.8 Nm/ms. Like its higher-powered siblings, the SC2 Sport features a strong, responsive force feedback experience that accurately conveys the nuances of the track.

For those demanding the current best, the Simucube Ultimate version delivers a staggering 32 Nm of peak torque and a industry-leading slew rate of 9.5 Nm/ms, which gives us unbeatable fidelity and responsiveness.

All three models feature high-resolution encoders, with the Sport and Pro using 22-bit sensors and the Ultimate sporting a 24-bit Hiperface encoder.

This high resolution enables the wheelbases to precisely track even the smallest steering inputs, resulting in a highly accurate and realistic force feedback experience for the driver.

Hardware and Build Quality

One of Simucube’s strengths lies in its use of servo motors. Compared to other direct drive systems that might use stepper or outrunner motors, servo motors offer several advantages. Firstly, a servo motor can maintain high levels of torque output, even at high rotation speeds with an excellent dynamic response.

For sim racers, this means that the force feedback remains strong and consistent, even when making quick steering corrections or during those moments when you’re catching big oversteer. The wheel will feel responsive and precise at all times, allowing you to make accurate inputs and maintain control in challenging situations. In contrast, a wheelbase with reduced torque at high rotation speeds may feel less stable and more difficult to control during rapid steering movements.

The build quality and design of Simucube 2 wheelbases can only be described as “industrial”, owing to the industrial roots of parent company, Granite Devices. That heavy-metal construction is quite iconic in the sim racing space, so much so that Chinese copies of the wheelbase design are rife. The wheelbase housings are machined in billet aluminium, with the Sport and Pro models featuring a textured black anodized finish and the Ultimate sporting a powder-coated exterior.

The Sport and Pro models use threaded M8 holes for secure mounting, while the Ultimate features pass-through holes for more flexible installation options.

The Quick Release (SQR) system is my favourite way to mount a wheel. It’s well-engineered – the tolerances on the machine work are such that there isn’t any flex in the wheel to wheelbase connection.

Flex simply isn’t part of the conversation for a Simucube owner,  This attention to detail in construction ensures that Simucube wheelbases can withstand the rigors of intense sim racing sessions and provide a solid, premium feel for the driver.

Electronics and Internals

A peek inside the Simucube 2 wheelbases reveals high-end component selection and a thoughtful design. The main circuit board houses a powerful STM32F722 processor, responsible for handling the complex force feedback calculations and digital signal processing. This onboard processor works to quickly and accurately translate the simulator’s physics into meaningful force feedback sensations for the driver.

The power delivery system is robust, with the revised R2 Sport and Pro models using a single power supply for ample headroom (the R1 version used two separate power supplies, and at some point it was deemed a single PSU was wider from an electronics engineering standpoint).

Simucube 2 uses a passive cooling system. By removing the need for fans, Simucubes run silently, unless the device is using the motor to generate a warning sound. For sim racers, this means a more immersive experience without the distraction of fan noise, as well as reduced maintenance concerns over the lifespan of the wheelbase.

Software and Customisation

Simucube’s True Drive software is easily the best example of wheelbase configuration software there is. The intuitive interface allows for adjustment of force reconstruction filters, torque bandwidth limiting, damping, friction, and inertia.

By tweaking these settings, sim racers can tailor the force feedback to their preferences, whether they prioritize raw strength, smooth response, or intricate detail.

The force reconstruction filter, for example, helps to smooth out the force feedback signal, reducing any notchiness or roughness in the steering feel. This is particularly useful when dealing with lower refresh rates from the simulator, ensuring a more natural and immersive experience. iRacing runs at 60hz, for example. Similarly, the slew rate limiting and peaking and notch filters allow users to fine-tune the response and eliminate any unwanted spikes or oscillations in the force feedback.

True Drive’s most powerful feature is its ability to create and share game-specific, car category specific profiles. Paddock (the feature in True Drive that enables this) is a gamechanger for users who would rather just go racing without a lengthy setup process. It also affords you the ability to tweak a professional profile. Here is Daniel Morad’s “Ultimate” setup:

Let’s analyse Daniel’s settings while looking at what they actually mean for you:

Max force in game: The maximum force output allowed by the game or simulator, set to 70Nm in this case.
Wheel Force: The maximum force output of the wheelbase, set to 32Nm (Simucube 2 Ultimate).
Smoothing, Damping, and Min force: Game-specific settings, all set to 0% in this profile.
Overall Strength: The master gain for all force feedback effects, set to 100%.
Steering Range: The maximum rotation angle of the steering wheel, set to 900 degrees.
Bumpstop feel: The sensation when reaching the end of the steering range, set to “Soft”.
Bumpstop offset: The position offset of the bumpstop, set to 0 degrees.
Reconstruction Filter: Smooths the force feedback signal, reducing notchiness. Set to 1 (Smoothness).
Torque Bandwidth (Lowpass filter): Filters out high-frequency noise in the force feedback signal, set to 2200 Hz.
Damping: Resistance to steering wheel movement, helps reduce oscillations. Set to 25%.
Friction: Constant resistance simulating steering system friction, set to 5%.
Inertia: Simulates the resistance to changes in steering wheel rotational speed, set to 0%.
Static Force Reduction: Reduces the constant steering forces while preserving dynamic forces, set to 35%.
Slew Rate Limit: Limits the rate of change of force output, set to 0 Nm/ms (no limit).
Ultra Low Latency Mode: Reduces latency by minimizing processing, set to 20%.
Center Frequency: The centre frequency for the notch filter (disabled in this profile).
Attenuation: The amount of attenuation applied by the notch filter, set to -24.50 dB.
Q-factor: The width of the frequency band affected by the notch filter, set to 0 (disabled).
DirectInput Effects Fine Tuning: These settings allow for fine-tuning of specific force feedback effects:
a. Damping: Set to 100%
b. Friction: Set to 100%
c. Spring: Set to 100%
d. Sine wave: Set to 100%
e. Square wave: Set to 100%
f. Sawtooth wave: Set to 100%
g. Triangle wave: Set to 100%

Combine seq. shifter with wireless wheel paddles: An option to combine sequential shifter inputs with the wireless wheel paddles (unchecked).
Static Force Reduction Speed: The rate at which static forces are reduced, set to 0.50 Nm/s.
Torque linearity (Gamma): Adjusts the linearity of the torque output, set to 1.00.
Center Damping: Additional damping applied near the centre of the steering range, set to 5%.
Center damping angle span: The angle range around the centre where centre damping is applied, set to 0 degrees.

Comparison: Simucube 2 vs Fanatec DD1/2

Torque: Compared to the Fanatec DD1 and 2, the Simucube 2 Pro and Ultimate boast higher peak torque figures, with the Ultimate’s 32 Nm surpassing the Fanatec DD2’s 25 Nm.

Slew Rate: Simucube 2 Ultimate’s 9.5 Nm/ms is notably higher than the Fanatec DD2’s 5.6 Nm/ms, which manifests itself in more responsive changes in force feedback. This can be particularly advantageous in situations where quick steering corrections are required, such as catching oversteer or navigating technical track sections.

Encoder Resolution: The Simucube 2 Pro and Ultimate also feature higher-resolution encoders compared to the Fanatec wheelbases. This higher resolution translates to a smoother and more nuanced force feedback experience.

Comparision: Simucube 2 vs Simagic Alpha and Alpha Ultimate

Torque: The Simagic Alpha offers a maximum torque of 15 Nm, which is lower than both the Simucube 2 Pro (25 Nm) and the Ultimate (32 Nm). While the Alpha’s torque output is respectable, the Simucube wheelbases provide a more powerful force feedback experience. The Alpha Ultimate, at 23 Nm peak torque, does not match the Simucube 2 Pro not the Simucibe Ultimate.

Response Time: Both the Simagic Alpha and Simagic Alpha Ultimate boasts a 1ms fast response time, which is comparable to the Simucube 2’s performance. This low latency ensures that the force feedback is delivered to the user with almost no delay, resulting in a highly responsive feel to the FFB. The Simucube 2 Pro and Ultimate also offer an ultra low latency mode.

Encoder Resolution: The Simagic Alpha and Alpha Ultimate both feature an encoder resolution of 262,144 points per revolution (ppr), which is lower than the 22-bit (4,194,304 ppr) and 24-bit (16,777,216 ppr) encoders found in the Simucube 2 Pro and Ultimate, respectively. Although the Simagic’s encoder resolution is quite high and should provide a smooth force feedback experience, the Simucube wheelbases offer even greater precision and detail in terms of steering input and force feedback output.

Conclusion

I’ve been running a Simucube 2 Pro since I upgraded from my Fanatec DD2 in 2019. I’ve never had any problems with it, and I always feel satisfied driving it. As a hobbyist sim racer I’m nowhere near to finding the limit of the device, and the Paddock feature in True Drive is a huge help in finding a good setup for every car I drive.

Paddock alone would sell the idea of this wheelbase to me, but as it happens, it’s technically a brilliant product too. The iconic “Simucube” logo on the side of the wheelbase chassis always brings a sense of completion to my sim racing setup, and to be quite honest I have no plans of entertaining changing to a new wheelbase anytime soon.

In conclusion, if you are a serious sim racer looking for the ultimate force feedback experience and are willing to invest in high-end equipment, the Simucube 2 lineup is an excellent choice. It’s by far the best direct drive wheel I’ve ever had the pleasure of using.

Scott Mansell from Driver61.com: What does a Pro Driver Think?

“The steering is of critical importance to be quick, especially, for drivers coming from the real world into the SIM, rather than just starting out in the sim.

We rely so heavily on feel and obviously, g-force, and the steering wheel really communicates to you what the car is doing.

In the simulator of course, the feedback you act on is visual and audible. But the steering wheel is where you feel everything through your hands, especially understeer, the oversteer, and the balance of the car.

We talk about driving technique on Driver61, all the time – understanding the balance in the car, how much the car is in rotation, or at least understanding when you have understeer or oversteer is really important to refining your technique, and becoming a quicker driver.

What I’m looking for is good communication, is the wheel able to give me a relatively similar feeling than I would get in a real racing car? And so that’s the feeling I’m looking for. It’s how the steering wheel loads up and then releases when I get some oversteer in the corner. Can I feel that very gentle release of torque, when I get some understeer as the front tires are sliding across the track?

I also want to make sure that the steering wheel has that weight to it, that it feels like a proper steering wheel, coming from the real world into the SIM, and, that it’s comfortable. When we’re spending a long time in the simulator, it’s important to me that it’s comfortable, and it features all of the buttons that you need to be able to make the required changes that you want.”

Scott Mansell, Founder: driver61.com

Simucube Direct Drive Wheelbases: Frequently Asked Questions

1. Is Simucube compatible with all racing sims?

Simucube wheelbases are compatible with most major PC-based racing sims, including iRacing, Assetto Corsa, Beam.NG, AMS2, Le Mans Ultimate, Assetto Corsa Competizione, rFactor 2, and many more.

2. Can I use any steering wheel with a Simucube wheelbase?

Simucube supports a wide range of sim racing steering wheels. Some steering wheels such as the McLaren Artura Pro have Simucube Wireless compatibility. The alternative is USB or Bluetooth connection directly to the PC.  Provided that the QR hub is Simucube Compatible on the “wheelbase side” and matches the PCD fitment (usually 70mm PCD) on the “wheel side”, it will work.

3. How do Simucube wheelbases compare to other direct drive options?

Simucube wheelbases are known for their high torque output, fast slew rates, and advanced customisation options through Simucube’s True Drive software. They are often considered among the best in terms of force feedback fidelity and overall performance, with the Simucube 2 Pro and Ultimate offering higher peak torque and slew rates compared to popular alternatives like the Fanatec CSL series, the DD1 and DD2.

4. Is it difficult to set up and tune a Simucube wheelbase?

While Simucube offers vast customisation options, True Drive is intuitive and very user-friendly. The ability to share and download profiles through the Paddock feature simplifies the setup process for less experienced users, allowing them to be able to immediately go racing without necessarily having to learn every tiny config option on the wheelbase.

5. Are Simucube wheelbases worth the investment?

Simucube wheelbases offer huge levels of realism, customisation options, and build quality. The long-term durability and extensive warranty coverage justify the investment for dedicated enthusiasts. My wheelbase is now 4 years old and has never caused any problems.

6. How do I update the firmware on my Simucube wheelbase?

 Updating the firmware on a Simucube wheelbase is a simple process using the True Drive software. When a new firmware version is available, the software will prompt you to update the wheelbase. Step by step, on-screen instructions are provided that prompt you to download and install the latest firmware. Despite the age of the 2 series, firmware updates are regular – the support for these wheelbases is extremely forthcoming.

7. What is the difference between the Simucube 2 Pro and Ultimate in terms of performance?

The main difference between the SC 2 Pro and Ultimate lie in the specified peak torque output, slew rate, and encoder resolution. The Ultimate offers higher peak torque (32 Nm vs. 25 Nm), a faster slew rate (9.5 Nm/ms vs. 8.0 Nm/ms), and features a higher-resolution encoder (24-bit vs. 22-bit) compared to the Pro. These enhancements result in even stronger, more responsive, and more precise force feedback for the Ultimate model.

8. Can I use a Fanatec wheel with a Simucube wheelbase?

While Fanatec wheels are designed to work with Fanatec wheelbases, it is possible to use them with a Simucube wheelbase using third-party adapters. However, it’s important to note that some features, such as button functionality or display integration, may not work as intended. For the best experience and full compatibility, it is recommended to use Simucube-specific or s compatible sim racing wheel with your Simucube wheelbase.

Glossary of Terms

Direct Drive: A type of force feedback system where the steering wheel is directly connected to the motor, providing the most realistic and responsive force feedback experience.
Torque: The rotational force generated by the motor, measured in Newton meters (Nm). Higher torque values indicate a stronger force feedback sensation.
Slew Rate: The maximum rate of change of torque, measured in Newton meters per millisecond (Nm/ms). A higher slew rate enables faster and more responsive changes in force feedback.
Encoder: A sensor that measures the position and rotation of the motor. Higher-resolution encoders, such as the 22-bit and 24-bit encoders used in Simucube wheelbases, provide more precise and smooth steering input.
Servo Motor: A type of electric motor that uses positional feedback to accurately control its rotation. Servo motors, like those used in Simucube wheelbases, provide high torque output and fast response times.
Quick Release (QR): A mechanism that allows for fast and easy attachment and removal of the steering wheel from the wheelbase.
True Drive: The proprietary software developed by Simucube for configuring and customizing the force feedback settings of their wheelbases.
Force Feedback (FFB): The technology that simulates the steering forces and sensations experienced in a real vehicle, providing a more immersive and realistic racing experience.
Paddock: A feature within the True Drive software that allows users to share, download, and customize force feedback profiles created by the community.
Simucube Wireless Wheel (SWW): A system that enables wireless connectivity between compatible steering wheels and Simucube wheelbases, providing a clean and convenient setup.
Passive Cooling: A cooling system that relies on heat dissipation through the wheelbase’s housing, without the use of active cooling components like fans.
Latency: The delay between the input from the simulator and the corresponding force feedback response from the wheelbase. Lower latency results in a more responsive and realistic experience.
Interpolation: The process of smoothing out the force feedback signal to reduce notchiness and improve the overall steering feel.
Damping: A setting that helps to reduce oscillations and overshoots in the force feedback, providing a more stable and controlled steering feel.
Friction: A setting that simulates the resistance felt in the steering system, providing a more realistic steering weight.
Inertia: A setting that simulates the weight and resistance of the steering wheel when changing direction, helping to replicate the steering feel of a real car.