How to Fit a QR Hub to a Sim Racing Wheel

Fitted to a QR hub - the Mercedes-AMG – GT Edition SIM Wheel

Featured Image: Mercedes-AMG – GT Edition sim racing wheel from Cube Controls.

It’s been a while since I last posted – life has been super busy and generally, I’ve wanted to do the *actual sim racing* rather than the writing. But today is different and we head into 2024 afresh with a new how to guide. Specifically, I’m going to take you, step by step through the process of fitting a QR hub to a sim racing wheel. And, as it happens I’ve got hold of the Mercedes-AMG – GT Edition sim racing wheel from our friends at Cube Controls.

You might have come across my guide to QR hubs which talks a lot about “PCD” fitment sizing and describes which hubs work with various wheelbases. If you’ve not read it I hope that’s useful for you – to summarise, a wheel is connected to your wheelbase via a QR hub. The hub is usually mounted to a QR adapter that is supplied with and bespoke to the wheel.

The radius of the fitment holes (sometimes threaded sometimes not so much) have standard diameters of either 50.8mm or 70mm PCD (Pitch Circle Diameter).

To get started, follow these steps:

Decide which Fixtures You’re Going to Use:

all the extras supplied with the sim racing wheel - nuts, bolts and tools
All the extras supplied with the sim racing wheel – nuts, bolts and tools

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.

Prepare the QR Hub Adapter

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

universal hub mount adapter - cube controls
Universal hub mount adapter – Cube Controls

This is the first time I’ve 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.

Bolt alignment through the drilled holes works perfectly
Bolt alignment through the drilled holes works perfectly – huge time saver!

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:

Rear of teh AMG wheel - note the pillars on the internal side of the wheel chassis
Rear of the AMG wheel – note the pillars on the internal side of the wheel chassis

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

tightening the M5 bolts to the rear of the wheel
Tightening the M5 bolts to the rear of the wheel

Note that the rear of the 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 (this is a review wheel supplied by Cube Controls). I see 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.

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:

completed universal hub installation and ready for the SQR hub
Ready to install 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:

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

If you go back to the previous image of the 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* adapter. 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:

Finger tightening the first bolt
Finger-tightening the first bolt

SQR hubs are a little quirky in that they never quite line up vertically. Place the QR hub on the rear and think about how the joint or hub commenting will mate with your wheelbase “wheelbase side hub”. 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.

tighten the bolts into the  hub adapter
Tighten the bolts into the hub adapter – I used my own hex / Allen bolts for this stage

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:

SQR Hub mounted to Cube Controls AMG wheel
SQR Hub mounted to Cube Controls AMG wheel

When you’ve finished admiring your work, you’re ready to go racing! Have fun and I’ll be back shortly with what I think about this rather beautiful new wheel:

Mercedes AMG Sim Racing Wheel
Mercedes AMG Sim Racing Wheel from Cube Controls

To support our site you can buy the Mercedes AMG wheel from your nearest retailer, or check out our current sim racing wheel reviews beginning with this wheel buyer’s guide. Enjoy!

How to Fit a QR Hub to a Sim Racing Wheel