Apex 18x9.5 Wheels on 2022 M3P Hitting Knuckle

[Reid_S]

I have a bit of an odd situation with a new set of Apex EC-7R wheels for my 2022 M3P.

I bought the 18 x 9.5 ET34 Model 3 wheels, wrapped them in Michelin Pilot Sport 4S 265/40R18 tires, and used 3mm spacers from MODEL+ to deal with the hub step. In theory, this set up should work. Despite all that, the front driver's side wheel is hitting the knuckle.

Before I drove it, I slipped a piece of cardboard between the knuckle and the wheel while the car was on stands to check the clearance. I also didn’t hear any scraping while I was backing straight out of the garage. It wasn’t until I turned the steering wheel to pull out of my driveway that I heard it.

It sounded like a light knocking. While I was coasting 100 yards to the next side street to turn around, I didn't hear anything, but when I turned the wheel again, the knocking came back.

When I got back to my garage, I took the wheel off and could see a section of the inner rim was scraping the knuckle.

It was just that one part of the wheel, though—it didn’t scrape around the whole circumference. Also, no rubbing on the tire. So, I cleaned off the spacer, the brake rotor hat, and wheel mounting surface. Put the wheel back on and went for another drive.

I got it up to about 45 mph and didn’t hear any knocking / scraping, but as soon as I started decelerating and turned to go through a roundabout, the knocking was back. I went back home, put my winter setup back on and reached out to Apex to get their thoughts.

Anyone have any ideas about what could be causing this? There was no shake in the steering wheel at 45 mph, so I don’t think the spacer is warped or anything like that. The wheel balanced just fine, so I don’t think it’s bent. Kind of at a loss.

 

[dsgerbc]

Maybe you're hearing it rub on the wheel speed sensor? Is it zip-tied to the knuckle?

 

[Reid_S]

Maybe you're hearing it rub on the wheel speed sensor? Is it zip-tied to the knuckle?

Good thought, but the wheel speed sensor is fastened to the knuckle. I can also see a scrape on the knuckle where the rim is making contact.

 

[MountainPass]

Can you please upload a photo of the knuckle where it touched?

 

[dsgerbc]

Well, the EC-7R is a new wheel, not many people here used it. It's the EC-7 that is known to fit. Maybe it's a feature.
Also, maybe try to measure the offset? Maybe you got a mis-labeled wheel?

 

[Ren.OG]

you need a slightly wider spacer.
if its rubbing on turns then its because of the tire sidewall deflection.

Edit: My konigs are 9.5's and i use a 10mm spacer for them, no need to move the speed sensor.

 

[Reid_S]

Can you please upload a photo of the knuckle where it touched?

Yeah, see below:

 

[travass808]

I had that same problem with Konig Hypergram 18x9.5 and 5mm spacers fixed it.

 

[Reid_S]

Heard back from Apex. They're recommending a 5mm spacer. Since their fitment guide says 3mm spacers will work for their ET34 wheels, I've asked whether they think it's the refreshed Model 3 knuckle that is the issue or if the EC-7R just requires a wider spacer than Apex's other wheels at a +34 offset. Will report back.

 

[MasterC17]

Heard back from Apex. They're recommending a 5mm spacer. Since their fitment guide says 3mm spacers will work for their ET34 wheels, I've asked whether they think it's the refreshed Model 3 knuckle that is the issue or if the EC-7R just requires a wider spacer than Apex's other wheels at a +34 offset. Will report back.

The knuckle was not changed on the refresh. This looks to be just a slight variance in the wheel issue. That being said, you will have no issues running 5mm spacers.

 

[Reid_S]

The knuckle was not changed on the refresh. This looks to be just a slight variance in the wheel issue. That being said, you will have no issues running 5mm spacers.

Thanks. Apex confirmed the fitment guide has a typo. Should be 5mm.

 

[Motion122]

Konig Ampliform 18x9.5 ET35 have a least a few mm space between the rim and the knuckle. Have you verified the wheel is indeed et34?

 

[SFLM3P19]

same wheel and tire setup. definitely needs 5mm or more.
I believe im running 8mm or whatever the max is for Performance stud length....

while i was on the goodyear F1 supercar 3s at 265, i rubbed through an ABS sensor wire... throw on more zip ties and be sure they run closer to the backside of the upright knuckle.

now im wanting super flush so im looking at the bolt through spacers for 20mm or more... cant seem to find anyone who has used these wheels with the bolt through spacers.... need to know if the wheel pockets are the right depth and size. 285s would be sick

 

[PrincessStela]

So... I run the EC-7 with centric hub rings and no spacers and have zero issues. 2020 M3P stealth, for what its worth.

 

[MasterC17]

So... I run the EC-7 with centric hub rings and no spacers and have zero issues. 2020 M3P stealth, for what its worth.

That's exactly why. Stealth/base rotors are about 5mm thicker than performance ones.

And again, they are similar style wheels, but absolutely not the same wheel as the EC-7R.

To expand on this, if you look at where the wheel is rubbing it's actually not the outer-most lip. It's an inner lip, but on a smaller diameter. The knuckle has less space the closer you get to the hub, so the overall diameter of the wheel is less relevant than the smallest diameter and then how far that is from the knuckle.

That being said, the same exact wheel but with a 19" overall diameter likely wouldn't have the same problem because the diameter of that inner lip would be larger therefore yielding more clearance to the knuckle.

 

[DOOLMTR]

This must be due to the thicker inner lip on the forged EC-7R. The best solution is to get the MPP rotor upgrades and just tell the wife they are 5mm spacers

 

[Motion122]

This must be due to the thicker inner lip on the forged EC-7R. The best solution is to get the MPP rotor upgrades and just tell the wife they are 5mm spacers

Paragon Performance is another good 2-piece rotor option.

 

[MountainPass]

This must be due to the thicker inner lip on the forged EC-7R. The best solution is to get the MPP rotor upgrades and just tell the wife they are 5mm spacers

Hahaha, I absolutely approve of this method. Does anyone need a written letter for their spouse from MPP?

 

[Reid_S]

Hahaha, I absolutely approve of this method. Does anyone need a written letter for their spouse from MPP?

HA! I literally had my finger on the trigger on the MPP website for the front rotors, but was a little worried 4mm might not be enough to clear the knuckle. I was ready with the "but babe, it'll make the car a lot safer" speech and everything.

 

[MountainPass]

HA! I literally had my finger on the trigger on the MPP website for the front rotors, but was a little worried 4mm might not be enough to clear the knuckle. I was ready with the "but babe, it'll make the car a lot safer" speech and everything.

I've had people ship the parts to their friend's house to avoid that conversation altogether