Quick Release: a Guide to QR Hubs for Sim Racing

Featured image: Cube Controls F-Pro with SQR QR Hub

I fit a new wheel to a QR hub on a near weekly basis – that’s not a flex, it’s the job. Reviewing sim racing wheels as a hobby means that I’ve fitted a lot of sim racing wheels, with QR hubs, ready to mount on whatever wheelbase I’m working with at that moment.

Today I’m going to cover what you need to know to demystify the subject, so that you can find a compatible QR hub for your wheel / wheelbase combination.

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It’s wise to do some pre-purchase research because there are different fitments depending on your wheelbase. Some, like Fanatec and Asetek have a proprietary or very unique way of mounting a QR hub to the wheelbase side. Compatibility, then, is key.

How will you mount your “6 x 70mm” PCD QR hub to your Simagic Alpha? And how does the Simucube 2 Pro work?

I’m covering off QR hub compatibility based on my experience with the direct drive wheels featured in my buyer’s guide. Here’s a list of the steering wheels I’ve worked with, which almost all feature a 70mm PCD fitment – I’ll cover what “PCD” means, too.

Contents:

• What does “6 x 70mm” PCD mean?
• How to fit a QR hub to a sim racing wheel
• Cross-Brand Compatibility – The Reality Check
• Fanatec QR1 and QR2
• Simucube
• Asetek
• SIMAGIC
• Moza
• VRS DirectForce Pro
• Thrustmaster T818 DD
• Accuforce
• Electronic Compatibility Solutions
• Common Compatibility Mistakes

By the time you’ve read this article you’ll know which adapter fitment (size) will match your sim racing wheel and wheelbase.

What does “6 x 70mm” PCD mean?

“PCD measurement” is the way a steering wheel fitment is described. There are usually 6 bolts mounting your steering wheel and most commonly they are arranged on a diameter of 50.8mm or 70mm PCD.

PCD stands for Pitch Circle Diameter and it’s the common way to describe a stud pattern:

So in the case of 6 x 70mm PCD, we’re saying there are 6 bolts placed on a diameter of 70mm. And just so you know, most of the time those are M5 (5mm) bolts. In almost all cases, there is a 70mm PCD drilled fitment arrangement on the back of your sim racing wheel.

Cross-Brand Compatibility – The Reality Check

Before we dive into the practical stuff, let’s address the elephant in the room: mixing and matching wheels from different brands. It’s not always straightforward, and here’s why.

Mechanical vs Electronic Compatibility

There are two parts to making a wheel work on a different brand’s wheelbase:

1. Mechanical Compatibility: This is the physical connection – can you bolt the wheel to the wheelbase? Usually solvable with the right adapter.

2. Electronic Compatibility: This is where it gets tricky. Will your buttons work? What about the display? Force feedback communication?

The good news is that the industry is slowly moving towards more open standards. The 70mm PCD mounting pattern is becoming universal, and USB connectivity means many wheels can work across brands – but there are still plenty of gotchas.

How to Mount a QR Hub to a Sim Racing Wheel

When you’re mounting a brand new rim or sim racing wheel, you will most likely come across a hub that is pre-drilled for 6 x 70mm bolt patterns. But you might also find that the hub is 6 x 70mm (wheel end) to 3 x 50.8mm (wheelbase end).

Take a look at the image above – this is how a QR hub arrangement looks between your steering wheel and the wheelbase:

Steering Wheel > Hub > Adapter > Wheelbase

With some careful thought, it’s easy to match one end to the other: match the wheel to the hub, match the hub to the adapter. The adapter fits the wheelbase and you can get going!

I’m going to demonstrate fitting a Simucube SQR hub to the Cube Controls Mercedes-AMG – GT Edition sim racing wheel.

To get started, follow these steps:

1. Decide which Fixtures You’re Going to Use:

Take a look in the box and decide on how you’re going to attach the wheel to your hub. I find laying out the individual pieces I’ll need very useful. Most large manufacturers supply these; otherwise, you’ll need to know the bolt size.

The bolts pictured are M5, the black bolts use a Torx head and the silver ones are plain M5 nuts and bolts. I’m going to use the Torx bolts supplied and my own Hex (Allen) bolts when fitting the SQR hub.

2. Prepare the QR Hub Adapter

Find the hub adapter supplied with the wheel, if it isn’t already fitted:

This was the first time I’d received a Cube Controls wheel without the Universal Adapter already attached. It took me a little while to realise it was supplied in the box (but that’s a story for the review).

Note from the image above that I’ve already threaded the bolts into the wheel side of the hub adapter. If you look closely, you’ll see that I’ve allowed the bolt threads to poke out of the other side, just a little. This will help me index the wheel side when it comes to fitting it to the wheel, which we do next.

3. Place the Hub Adapter on the Rear of the Wheel Body

Using those little threaded ends, you can place the hub very quickly. Here’s the rear of the AMG wheel with the threaded holes and pillars visible. This is what you’ll be mounting the adapter to:

If you gently place the hub in roughly the right place you’ll feel the ends of the bolts index themselves ready for tightening:

Note that the “wheel side” of the Cube Controls hub adapter is 50.8mm PCD and the QR hub side end of the adapter is 70mm PCD.

I’m perfectly happy using 3 of the supplied bolts to make a triangle as, from experience, 3 bolts is enough. But you can go further if you’re planning on leaving the wheel mounted for a long time, there’s no harm in using a tiny amount of screw lock compound to be extra certain they can’t loosen with time.

Work methodically around the fitting, at first get the bolts “finger tight” and then tighten the M5 bolts down as best you can. It’s doubtful you’ll over-tighten them with your fingers – don’t be afraid to use a decent amount of torque.

Work your way back around the bolts to double-check the tightness of each one.

4. Mount the QR Hub to the Hub Adapter

I should save it for the review but the ease of fitting these wheels by comparison to some other brands I’ve worked with is significant. And you get a red anodized aluminium hub for your trouble! I wish there was a red anodized SQR hub:

Note that my SQR hub is pre-assembled – for instructions on how to assemble the SQR hub itself, scroll down to “SQR Hub installation” on this Simucube 2 review.

Assuming you have the QR hub ready to install, we’ll move to the next step:

5. Arrange the Bolts around Your QR Hub Base and Place onto the Wheel

If you go back to the previous image of the QR hub side of the Cube Controls hub adapter you’ll notice that there is a 50.8mm PCD diameter mounting option on the inner ring and the outer ring is 70mm.

I use a wheel hub extension with a 70mm *unthreaded* BG Racing Extension adapter. Extensions are optional, by the way! This makes the Universal hub all the more useful as all of the holes are drilled. To have the choice of both PCD fitments is nice, too:

SQR hubs are a little quirky in that they never quite line up vertically. There’s always a bit of offset, for which you simply recalibrate the centre position once the wheel is fitted.

Work your way round placing the bolts in each of the threaded holes.

Work your way around the hub, tightening each bolt. Then do a second round to check the tightness. Don’t be afraid to use as much torque as your hands can muster.

Once you’ve completed the task, you’ll be able to mount the wheel:

Simucube

The Simucube wheelbases come with a wheelbase side SQR hub supplied. The SQR hub kit will accommodate any 50.8mm or 70mm PCD wheel (the wheel side mount is tapped with M5 threads.

You’ve seen in my “how to install a QR hub” section, a “wheel side” SQR being fitted – here’s the wheelbase side:

There are, of course, other compatible QR options for the Simucube 2 series:

Simucube Quick Release (SQR): This is a direct fit for the Simucube 2 Pro as I’ve demonstrated above. It’s my preference as it’s the manufacturer supplied hub.
Buchfink Q1R: This is another option that is compatible with the Simucube 2 Pro.
Sim-Lab Xero-Play V3 Quick Release: Featured in the images at the start of the article, it’s SC compatible and has a lovely anodised finish.
QRX Simucube Adapter by Cube Controls: The QRX adds some USB throughput functionality to minimise cable issues.

Mounting any other QR hub to the wheelbase side of a Simucube is the tricky bit, as they have a unique 3 bolt pattern. If you want to use an alternative (non-Simucube) QR mount, you can mount it to the existing SQR components or (better) take the wheelbase side SQR system off entirely, and mount an Ascher Racing 70mm SQR adapter in its place.

The Ascher adapter will allow a 70mm or 50mm bolt pattern item to mount directly onto the Simucube shaft from which you can attach any QR hub or spacer directly to the wheelbase.

Fanatec: QR1 and QR2

Fanatec very recently updated their somewhat maligned QR1 hub with the revised QR2:

Fanatec is a closed “ecosystem”, meaning that only a Fanatec wheel is intended for a Fanatec DD wheelbase (like my CSL DD). You can mess around making non-Fanatec wheels compatible with the Fanatec Podium QR hub, but in my experience most sim racers are either in the Fanatec ecosystem, or they’re not.

Chances are if you have a wheelbase fitted with the QR2 variant, you already have the correct QR2 wheelside hub attached to your Fanatec sim racing wheel.

The problems start for owners of “legacy” Fanatec wheels, that have the QR1 mount fitted to them. My best advice is buy the QR2 wheel side mounts hub for your Fanatec wheels (sorry!).

Mounting non-Fanatec wheels with the Podium Hub

If you own a QR1 variant of a Fanatec direct drive wheelbase, you may want to experiment with wheels outside of the Fanatec ecosystem. This is where the Podium Hub becomes useful:

As I wrote in the review, this is a quick-fix solution to build up a wheel rim and button plate (like this rather nice Turn Racing BP2 and R305 rim) ready to mount on your Fanatec wheelbase.

You can mount paddle shifters on the side and mount a simple rim directly on the Podium hub to build a really simple replacement wheel.

The SimRacingMachines Solution

Here’s where things get interesting. SimRacingMachines (SRM) has basically cracked the Fanatec ecosystem wide open. They offer two types of solutions:

1. Mechanical Adapters: These let you mount Fanatec wheels on other wheelbases using standard 70mm PCD patterns. Perfect if you’re moving from Fanatec to Simucube, VRS, or similar.

2. USB Conversion Kits: This is the game-changer. SRM’s conversion kits turn your Fanatec wheel into a standalone USB device. Your buttons, paddles, displays – everything works on any wheelbase that accepts USB wheels. At £100-300 depending on the wheel model, it’s not cheap, but it means you can take your favourite Fanatec Formula wheel to a Simucube without losing any functionality.

The USB conversion is particularly clever because it completely bypasses Fanatec’s proprietary communication protocol. Once converted, your wheel is just another USB device as far as your PC is concerned.

Asetek

If you own an Asetek wheelbase, you’ll have their standard QR hub mount attached to the wheelbase side. You probably own a Forte, La Prima Formula Steering wheel, too – which is supplied with the compatible QR hub attached.

If, however, you want to add a new wheel, it might be wise to check out the options. I have this Asetek QR for Artura Series hub, for my Artura wheel:

Note how it has a USB connection inside the hub, so that the wheel can piggyback the USB connection through the wheelbase, alleviating the need for a cable.

Cube Controls also make an aftermarket hub for the Asetek series of wheelbases. Check out this Cube Controls Asetek Invicta Quick Release Adapter:

The key thing to know about these Asetek compatible hubs is that the wheel side PCD fitment is 70mm PCD. Thus, the wheel compatibility is universal.

SIMAGIC

Having recently reviewed the GT NEO, I can show you the standard hub that comes fitted with all SIMAGIC wheels, the QR50:

The SIMAGIC QR hubs are a ball bearing type hub adapter – they click into place when you pull back the lip. It’s a very secure fitting and mates perfectly with the wheelbase side QR system.

Depending on the wheel fitment you’re using, SIMAGIC makes an adapter in either 50.8mm PCD (QR50) or 70mm PCD (QR70):

Additionally, there are aftermarket solutions available too. For example, there’s a QR adapter designed for the Alpha Mini available on Thingiverse. This adapter allows you to mount a wheel or aftermarket quick-release directly to a Simagic wheelbase.

If you’d like to mount your favourite rim on a Simagic wheelbase, something like this GT Pro Hub and QR button box would work:

In my GT NEO review, I fitted a SIMAGIC wheel to my Simucube 2 Pro wheelbase with the MAGLINK adapter plate and an SQR hub:

The QR hub adapter plate mounts snugly on the back of a SIMAGIC wheel:

MOZA

Moza wheels and wheelbases tend to be part of an ecosystem which means it’s pretty unlikely that you’ll need a QR hub. If however, you have a non-Moza wheel that you’d like to mount to your wheelbase, try this:

This NRG style adapter is compatible with the R5/R9/R16/R21 wheelbases, featuring a standard 70mm PCD wheel side fitment.

Mounting a Moza Wheel to a Simucube Wheelbase

If you want to use a Moza wheel on a Simucube wheelbase, you’ll need Moza’s 70mm PCD hub adapter kit. This clever solution allows you to mount any Moza wheel to a third-party wheelbase that accepts standard 70mm PCD mounting patterns.

The process is straightforward:

1. Remove the Moza QR from your Moza wheel
2. Attach the Moza 70mm PCD adapter plate to the back of your Moza wheel
3. Mount your preferred QR hub (like the Simucube SQR) to the adapter using the 70mm bolt pattern
4. Connect to your Simucube wheelbase as normal

This adapter essentially converts Moza’s proprietary mounting system to the industry-standard 70mm PCD pattern, opening up compatibility with Simucube, VRS, and other high-end wheelbases. The adapter maintains the structural integrity needed for high-torque direct drive systems whilst preserving the USB connection for the wheel’s buttons and displays.

VRS DirectForce Pro

The VRS DirectForce Pro is a serious bit of kit that’s often overlooked in compatibility discussions. It’s basically an OSW (Open Sim Wheel) derivative, which means it plays nicely with the standard 70mm PCD ecosystem.

VRS offers their own hub adapter that allows you to mount any 70mm PCD wheel, quick release, or OSW conversion kit. The beauty of the VRS system is its simplicity – no proprietary nonsense, just standard mounting patterns that work with virtually any aftermarket wheel or QR system.

Compatible QR options include:

• NRG-style quick releases (most common)
• D1 Spec quick releases
• Any 70mm PCD adapter plate
• Custom 3D-printed solutions from the community

Thrustmaster T818 DD

Thrustmaster’s entry into the direct drive market brings their own QR system, but thankfully they’ve embraced some level of standardisation. The T818 uses a proprietary QR system on the wheelbase side, but the wheel side accepts standard 70mm PCD patterns.

This means you can:

• Use any Thrustmaster wheel designed for the T818
• Mount third-party wheels using the Thrustmaster QR adapter
• Create custom solutions with 70mm PCD compatibility

The catch? Electronic compatibility is limited to Thrustmaster’s ecosystem unless you go full USB conversion.

Accuforce

The Accuforce system from SimXperience is another OSW-based platform that embraces open standards. Like the VRS, it uses standard 70mm PCD mounting, making it compatible with virtually any aftermarket wheel or QR system.

Key compatibility points:

• Standard 70mm PCD on the wheelbase shaft
• Works with any OSW-compatible QR system
• No proprietary adapters needed
• Full USB support for third-party wheels

Electronic Compatibility Solutions

While mechanical compatibility gets your wheel physically attached, electronic compatibility determines whether your buttons, paddles, and displays actually work. Here’s the current state of play:

USB Conversion Kits

The gold standard for cross-brand compatibility. These kits bypass proprietary communication entirely:

• SimRacingMachines: Fanatec wheel conversions (£100-300)
• Sim-Hub: Universal USB interface boards (£50-150)
• DIY Solutions: Arduino-based conversions (£20-50)

Wireless Solutions

Some manufacturers now offer wireless wheel connectivity:

• Simucube Wireless: Built into ActivePedal and newer wheels
• Asetek Wireless: Integrated into their ecosystem
• Aftermarket Bluetooth: Various DIY solutions available

Common Compatibility Mistakes

After helping countless sim racers with compatibility issues, here are the most common mistakes I see:

1. Assuming All 70mm PCD Patterns Are Identical

While 70mm PCD is becoming standard, not all implementations are the same. Some use threaded holes, others use through-holes. Always check whether you need:

• M5 bolts (most common)
• M6 bolts (less common)
• Through-bolts with nuts

2. Ignoring Electronic Compatibility

Just because it fits doesn’t mean it works. Before buying:

• Check if the wheel needs proprietary communication
• Verify USB compatibility
• Research conversion options
• Budget for additional adapters/converters

3. Over-Tightening Bolts

I’ve seen too many stripped threads from over-enthusiastic tightening. Remember:

• M5 bolts: 5-8 Nm maximum
• Use a torque wrench if unsure
• Aluminium threads strip easily
• When in doubt, less is more

4. Mixing QR1 and QR2 Fanatec Components

This is a recipe for disaster. The systems are NOT compatible:

• QR1 wheels need QR1 wheelbases (or adapters)
• QR2 wheels need QR2 wheelbases
• Mixing can damage both components
• Budget for full ecosystem upgrade

5. Forgetting About Warranty Implications

Cross-brand compatibility often voids warranties:

• Check manufacturer policies first
• Document your setup before modifications
• Keep original parts for warranty claims
• Consider the risk vs reward

My Recommendations

After years of mixing and matching equipment, here’s my advice:

For Maximum Compatibility

Go with Simucube or VRS wheelbases. Their open approach to mounting standards means you can use virtually any wheel with the right adapter. Yes, they’re expensive, but the flexibility is worth it.

For Ecosystem Simplicity

Pick a brand and stick with it. Fanatec, Moza, or Simagic all offer complete ecosystems that just work. No compatibility headaches, everything talks to everything else.

For Budget-Conscious Builders

Start with a wheelbase that uses standard mounting (avoid proprietary systems). Build your wheel collection gradually, focusing on USB-compatible options.

For the Tinkerers

Embrace the chaos! Get a Simucube or VRS base, collect various QR systems, and enjoy the flexibility. Just budget for adapters, converters, and the occasional compatibility surprise.

Quick Reference Table

Here’s a quick compatibility matrix for the major brands:

Wheelbase	Native QR	Wheel PCD	Cross-Brand	USB Support
Simucube	SQR	50.8/70mm	Excellent	Full
Fanatec	QR1/QR2	Proprietary	Limited	With Podium Hub
Moza	Moza QR	70mm*	Good	Yes
Simagic	QR50/70	50.8/70mm	Good	Yes
Asetek	Asetek QR	70mm	Good	Full
VRS	Various	70mm	Excellent	Full
Thrustmaster	T-QR	70mm	Limited	Limited

*With adapter kit

Final Thoughts

QR hub compatibility in sim racing is getting better, but we’re not quite at universal plug-and-play yet. The industry is slowly converging on 70mm PCD as a mechanical standard, which is brilliant. Electronic compatibility remains the wild west, but USB solutions are becoming more common.

My advice? Do your research before buying. Check forums, ask questions, and don’t assume compatibility. And when in doubt, remember that adapters exist for almost every combination – you just need to find the right one.

The beauty of sim racing is that there’s always a solution, even if it involves a bit of creative engineering. Just remember to keep those M5 bolts under 8 Nm, and you’ll be fine!

Happy racing, and may your quick releases always be… quick.

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