M Carbon Ceramic Brakes - Serious Wheel Clearance Issue (rocks / stones)

[Geordie33]

Gentelemen, one wheel I had damage of at least 2mm deep groove. Let's assume the wall thickness on the barrel is 5mm. I thing this is a significant weakening of the rim and even worse a sharp stress raiser. BTW .....BMW asked that my damaged wheel be shipped back to them for engineering analysis.

[MWcoupe]

Petition to have free 20" wheels upgrade for all CCB owners

[Geordie33]

Strongly agree

[Brosef]

if BMW makes 20" wheels a requirement for CCB's, I'm going to have to pass on them. 20" wheels just aren't for me. there must be another solution. Maybe a little plastic piece at the bottom of the caliper that gets real close to the barrel (almost like a scraper)? just pulling things out of my ass.

[MatthewDavid]

I haven't inspected yet, but does anyone know if adding a spacer, even a small one, increases wheel to caliper clearance and does that address the issue in this thread?

[MatthewDavid]

Wait... what other horror stories? I agree this is a design issue, but BMW appears to be assessing (?) Has anyone confirmed it's a safety concern?

The only other complaints I've seen about CCBs are 1) hearsay arguments about Porsche owners from non-Porsche owners 2) some squeaking and 3) modestly and temporarily diminished responsiveness in heavy rain or after exiting a car wash.

Originally Posted by AM4ZING

Keep up updated. I am awaiting delivery of my M4 with CCB option and have read too many horror stories

[2000cs]

Not just a CCB problem, as there are reports, including mine, of the same thing happening on non-CCB cars with 18 inch wheels. I like the caliper idea, maybe a couple of pieces of duct tape to see if it helps, then a permanent fix? The alternative would seem to be 19 inch wheels on non-CCB cars, and 20 inchers on the CCB cars.

[RowanBuds]

Originally Posted by 2000cs

Not just a CCB problem, as there are reports, including mine, of the same thing happening on non-CCB cars with 18 inch wheels. I like the caliper idea, maybe a couple of pieces of duct tape to see if it helps, then a permanent fix? The alternative would seem to be 19 inch wheels on non-CCB cars, and 20 inchers on the CCB cars.

How about re-designed wheels altogether - I think the MORR 19's have 3-6mm more clearance than the BMW OEM 19's; could be wrong but I think I saw that in one of the MORR wheel/tire threads.

[Mark's M]

That's correct. 6-8mm clearance I believe. More than the size of your average pebble. I don't want 20's either, they do absolutely nothing for performance and add unnecessary weight. But if that's what BMW comes up with for a fix, I'll take it. I was somewhat forced to take the CCB's as a part of the amazing Canada euro delivery experience this year and tried to negotiate them out. They couldn't do it and over a couple of weeks I accepted the fact and was actually quite excited to be getting them. And then this thread popped up. I was hoping they didn't come with complications (beyond what I've researched which I was more than prepared to accept) but this issue has deeper implications IMO.

Thanks for the updates Geordie, appreciated.

[Mark's M]

Originally Posted by Brosef

if BMW makes 20" wheels a requirement for CCB's, I'm going to have to pass on them. 20" wheels just aren't for me. there must be another solution. Maybe a little plastic piece at the bottom of the caliper that gets real close to the barrel (almost like a scraper)? just pulling things out of my ass.

Good thought but in our climate (I'm assuming you get the same crappy, ultra freezing weather I do with lots of ice potential besides pebbles) I don't know that a fix like that would be able to take it. The last thing I'd want is stress on the calipers, even the least little bit, under extreme weather conditions. In lieu of a 20" wheel, the fix could simply be a re-engineered 19 in the manner that Morr designed their VS52.

I am surprised that BMW and Brembo didn't collaborate on this before it became an issue. You'd think something like this would've been caught in pre-production testing??? Interested and invested as to how this turns out.

[gogoevo]

20" are not for me, either. I just installed 19" HRE R101's tonight, and the clearance is much better. I can get a finger in there now, whereas the OE wheels you would be lucky to get a couple of dimes in there.

[Brosef]

Originally Posted by Mark's M

Good thought but in our climate (I'm assuming you get the same crappy, ultra freezing weather I do with lots of ice potential besides pebbles) I don't know that a fix like that would be able to take it. The last thing I'd want is stress on the calipers, even the least little bit, under extreme weather conditions. In lieu of a 20" wheel, the fix could simply be a re-engineered 19 in the manner that Morr designed their VS52.

I am surprised that BMW and Brembo didn't collaborate on this before it became an issue. You'd think something like this would've been caught in pre-production testing??? Interested and invested as to how this turns out.

I think you underestimate the immense amount of stress that calipers are put through in order to stop these cars so aggressively. having taken the Brembo calipers on and off many times in my e92, I can tell you that these things are extremely stout, and for an obvious and good reason.

[Mark's M]

Originally Posted by Brosef

I think you underestimate the immense amount of stress that calipers are put through in order to stop these cars so aggressively. having taken the Brembo calipers on and off many times in my e92, I can tell you that these things are extremely stout, and for an obvious and good reason.

Good to know, and thanks. One less thing to worry about.

[CSanto]

OP I just checked my wheels. I have the same issue. So I spent 8k for an option that's damaging my wheels. Pathetic. I plan on bringing this up to BMW immediately. I just bought the car and I don't have 8k laying around to buy a set of HREs

[Geordie33]

I can't believe that it took so long to get this thread running on this subject. This is a design flaw and if you look at the benchmark no one has this minimal amount of clearance. Seriously I wonder if M Division Vice President Engneering Albert Biermann jumped to Hyundai before he was pushed?

[absoluteis350]

Originally Posted by Geordie33

I can't believe that it took so long to get this thread running on this subject. This is a design flaw and if you look at the benchmark no one has this minimal amount of clearance. Seriously I wonder if M Division Vice President Engneering Albert Biermann jumped to Hyundai before he was pushed?

So do we have actual evidence that BMW is working on this ? Short of redesigning the calipers (I seriously doubt they would do this) up-sizing the wheels is the only cost effective option for them. Cost-effective as in they would pass the cost directly onto the consumer with 2016+ cars. As someone mentioned, they could also redesign the wheel

Originally Posted by Geordie33

Currently this issue is with M Division, I suggest all of you with issues push for a resolution also. For me it's a clear recall.......not fit for function normal road driving. I heard 2 of my 4 issues happen its 20-30mph driving.
BTW I am in the Automotive business at a professional engineering level. I know what this looks like form the OEM standpoint. I won't let this one go. Maybe later I will ask to collect all VIN numbers effected and expedite thru legal.

Yes, please keep us updated and let us know if there is something we can do to help.

[CSanto]

Originally Posted by Geordie33

Shows Brake Caliper damage at lower edge you can see where the stone goes into the ~5mm gap and get forced thru causing the damage to the wheel at the same time.

Have they done anything about the Caliper Damage?

I'm trying to plan my attack on BMW lol. 8,500 dollar option...I'm definitely not letting this be.

I'll PM you my VIN when I go outside for lunch.

[Brosef]

Originally Posted by CSanto

OP I just checked my wheels. I have the same issue. So I spent 8k for an option that's damaging my wheels. Pathetic. I plan on bringing this up to BMW immediately. I just bought the car and I don't have 8k laying around to buy a set of HREs

more cases? damn, this is really damping my desire for CCB's. I hope they can find an appropriate solution to this that doesn't require 20" wheels. maybe the ZCP wheels? I'm sure that's optimistic.

[CSanto]

Originally Posted by Brosef

more cases? damn, this is really damping my desire for CCB's. I hope they can find an appropriate solution to this that doesn't require 20" wheels. maybe the ZCP wheels? I'm sure that's optimistic.

Believe me I'm not happy. I loved the CCB and said they were worth every penny up until this happened.

[Geordie33]

Need to hear from more who found this issue. I am promised a response by M division in 2 weeks from now (I am on an Asian business trip). I don't expect to be fobbed off as I have a solid dealer allie in this one. More pictures of your damaged rims is needed, and YES please take to your dealer the more reported cases the higher this issue will spike on the in filed warranty data....seriously this is how it works. It's PPM problems per million as a metric. We only need 25+ cases and it's straight I number one M product warranty as the CCB are a limited option. Thanks in advance.

[Mark's M]

Originally Posted by Geordie33

Need to hear from more who found this issue. I am promised a response by M division in 2 weeks from now (I am on an Asian business trip). I don't expect to be fobbed off as I have a solid dealer allie in this one. More pictures of your damaged rims is needed, and YES please take to your dealer the more reported cases the higher this issue will spike on the in filed warranty data....seriously this is how it works. It's PPM problems per million as a metric. We only need 25+ cases and it's straight I number one M product warranty as the CCB are a limited option. Thanks in advance.

You should send a note to one of the Moderators asking that this thread 1) be made into a "CCB problem/Issue" thread with the potential for safety concerns and 2) that it be moved from this sub-forum to the general forum and then "stickied" so that it doesn't disappear from the front page.

There are a lot more CCB owners out there that may not be interested in wheels/tires and therefore don't look here. And probably a lot more on order. There are a group of Canadians going to the Welt in June to pick up 10 M3's/4's. All of them will be equipped with CCB's, mine included. I WANT these brakes but not at the expense of having to deal with this sort of issue. I truly hope BMW will come up with a solution and knowing BMW as I do, I'm confident they will.

[M4TW]

Originally Posted by Mark's M

You should send a note to one of the Moderators asking that this thread 1) be made into a "CCB problem/Issue" thread with the potential for safety concerns and 2) that it be moved from this sub-forum to the general forum and then "stickied" so that it doesn't disappear from the front page.

There are a lot more CCB owners out there that may not be interested in wheels/tires and therefore don't look here. And probably a lot more on order. There are a group of Canadians going to the Welt in June to pick up 10 M3's/4's. All of them will be equipped with CCB's, mine included. I WANT these brakes but not at the expense of having to deal with this sort of issue. I truly hope BMW will come up with a solution and knowing BMW as I do, I'm confident they will.

The clearance is indeed tight, but it is even tighter on the OEM winter wheels on which I have been driving all winter on gravelled roads. I haven’t niticespd any damage so far. I'm not sure how much larger the gap between calliper and wheel with the stock brakes is anyway - but I imagine a large enough stone could become lodged there as well.

I think you need to relax more and enjoy the anticipation of your new catr. You are in for an incredible experience by all accounts. Meanwhile, who knows how large of an issue this actually is (without discounting anyone's experience). If a fix is required, and the fix is a new wheel, then you can use the opportunity to get grippier tires.