Challenges with Fitting Wheels to Brembo 17Z Calipers

Attempt 1 – Wheels from Audi S1

• Wheel size: 7,5J X 18″ ET37,5
• Part number: 8X0601025CC (matte black) or 8X0601025BS (dark gray metallic)

Initially, I planned to use 18″ wheels from the S1 because they look quite nice and have the same diameter as the wheels from Polo WRC Street. I was counting on the fact that since the wheels are half an inch larger than typical Polo wheels, they should easily accommodate Brembo 17Z calipers.

In the meantime, I saw that Michel had the same calipers with standard 17″ Mallory wheels (from Polo 6R R-Line) on 27mm spacers, which gives us ET 19 (46 – 27).

Similarly, 39.5 – 19 = 19.5, so theoretically they should fit with 20mm spacers. Unfortunately, as it later turned out, the Audi S1 wheels on a 20mm spacer stuck out too far beyond the car’s outline. To fit them properly, I would need aftermarket fiberglass widened fenders, but this option was immediately ruled out – I’m not a fan of those Mucke fenders – I simply don’t like them and in my opinion, they don’t match the rest of the car’s form, and it’s a bit silly to widen just the front while leaving the rear stock…

The spoke on the S1 wheels is very thick (in depth) – it’s 34mm thick and has no “bulge” at the caliper location.
To make it possible to tighten the wheels and allow them to rotate freely, a minimum 21mm spacer would be needed.

Attempt 2 – Mirabeau 17″

• Wheel size: 17″x7J ET46
• Part number: 6C0601025B88Z

Since Michel’s 17″ Mallory wheels fit, Mirabeau should be similar. I took wheels with Mirabeau rims from an older Polo and decided to try. With a 25mm spacer, the wheel almost fits, but unfortunately, after tightening the wheels, there’s no possibility of wheel rotation. There were two options: a larger spacer or grinding the calipers. They are made of aluminum and their shape can be easily changed; I saw that many people on YouTube did this when installing them in cars like Lexus, etc.

Using an even larger spacer was also ruled out because at 25mm, the suspension already behaves rather awkwardly. Too large a spacer causes the wheel to tilt even more when turning and generally doesn’t have a positive effect on suspension components.

The thickness of the Mirabeau wheel spoke is about 23mm:

At higher speeds, navigating corners with such a setup may not be very safe… As for spacers, for me 10-15mm is the maximum. I also don’t like smaller ones because they usually don’t have a centering collar, and with something like 5mm, 99% of the time we’ll have wobbling when driving above 120km/h because it’s difficult to center properly, and when tightening the wheel, the spacer usually drops slightly…

Attempt 3 – OZ Racing 17″ Leggera HLT Wheels

• Wheel size: 7.5×17 ET48
• Part number: W01975201H1

So the wheels from Audi S1 were set aside, and because there aren’t many nice OE wheels in 18″, I decided to try OZ. Many people use them with larger calipers, and the company has a fairly good reputation for an aftermarket manufacturer. Everyone mainly uses OZ Ultraleggera or Superleggera wheels – practically every other Polo on Instagram has these wheels, so I’m quite tired of seeing them. I set my sights on the Leggera HLT model, which has a shape similar to the factory layout of 5 double-spoke arms.

Unfortunately, the OZ Leggera HLT wheels couldn’t be mounted even on 25mm spacers due to the specific wheel construction (even though it’s half an inch wider, it’s very shallow, and the spokes, which appear thin from the front, are actually thick in depth, especially at the caliper location.

Even with a 30mm spacer, it wouldn’t fit with Brembo 17Z calipers. The spoke thickness is much greater than in the earlier Audi S1 wheels…

So the OZ wheels also went aside. Fortunately, I only bought two for testing 😀

Interestingly, one wheel weighs only 7.65 kg, which is significantly less than a classic alloy wheel from VAG.

When I was test-fitting these wheels, it was quite cold, and I didn’t want to scratch them, so I didn’t take any measurement photos because I couldn’t even mount the wheel on the hub…

You can find more wheel photos here.

Attempt 4 – Barcino 17″

• Wheel size: 17″x7J ET43
• Part number: 6J0601025Q8Z8 (silver) or 6J0601025QBA1 (black)

And suddenly, a better solution appeared. Matthew (mih11mi6), who has a 2.0 TSI Ibiza and replaced his Brembo juniors with Brembo 17Z. His old wheels from the Ibiza FR (similar to Volkswagen’s “Mirabeau”) didn’t fit, but with “Barcino” wheels from the post-facelift Cupra 6J on a 15mm spacer, there were no more problems. These wheels were designed for the Cupra with factory AP Racing four-piston calipers (by the way, it’s strange that the Ibiza came with better brakes than the VW Polo…).

In the Cupra wheels, the spoke dimensions are about 24mm thick, so similar to Mirabeau, but due to their convex shape, they have about 10mm clearance between the spoke and the caliper:

I started searching for the wheels. Unfortunately, in Poland, the Ibiza Cupra wasn’t as popular as in the UK, and it’s not so easy to find nice wheels from it. I was looking for silver ones, but since black ones turned up and I needed wheels, I bought the black ones.