[chris719]

Originally Posted by CoffeeLife

Hmm. Is this a requirement?
I run CT 1521s on the street and never added the rear pad shims for the 4P rear.

On another note...I really enjoy the 1521s compared to the Pagid and Ferodo 2500 street pads I was running before.

The shim is not a requirement, it's just possible you get some noise when changing directions. In what way do you like them compared to the DS2500?

[CoffeeLife]

Originally Posted by chris719

The shim is not a requirement, it's just possible you get some noise when changing directions. In what way do you like them compared to the DS2500?

Ah thats good to hear haha.... Ill just enjoy the extra rattle as the car is slowly being stripped anyways.

The DS2500s squeal quite loudly after getting wet and drying. As it rains out here a lot, was a minor annoyance. I am use to all my pads squealing to some extent. Additionally the deposits of the Ferodo compounds seem to be pretty extreme. Was a chore to scrub from wheels.

I dont believe I felt any difference when stopping on the street if either brands pads were cold vs warmed up. However, the carbotechs feel more linear after they get some heat in them.

Additionally comparing Ferodo 3.12 and 1.11s to the Carbotech XP10.....

I was very pleased with the XP10s during my race last weekend. Minimal residue caked on the wheels compared to the Ferodo 3.12 / 1.11s and extremely confident feel during all brake zones.


Overall I did enjoy my Ferodos when I ran them, but all 3 of my sets were under 30% life and I decided to try another brand. Happy with the change to CTs for now

[///MPhatic]

Originally Posted by CoffeeLife

Hmm. Is this a requirement?
I run CT 1521s on the street and never added the rear pad shims for the 4P rear.

On another note...I really enjoy the 1521s compared to the Pagid and Ferodo 2500 street pads I was running before.

It's not a requirement, but the very loud clicking most get without the shim is well documented.

The 1521 is ok, but not nearly as good as the Akebono's for street use. They're somewhere in between stock and Akebono's. Of course, if you hit the twisties hard or do an HPDE here and there they are ok, whereas the Akebono's aren't.

[KevinC]

1521's went on today. Haven't had much of a chance to sample them yet, but so far, so good. I have actual pedal feel now and the brakes are properly easy to modulate. With the stock pads, far too grabby, and inconsistently so. No more pulsating. I haven't heard any clicking/clunking yet. My mechanic did, and he had a second look to make sure nothing was moving unexpectedly. Just the nature of the beast.

My dude chose not to turn the rotors, felt it wasn't necessary, despite Carbotech's insistence that they should be turned. He's got a great local rep and I have nothing but positive past experience with him so I'm gonna have to trust his judgment. Hopefully no ill effects long term. I'll update the thread in a few days when I've had a chance to put some miles on them.

[KevinC]

Footnote on ordering 1521's - Carbotech gives a BMWCCA discount, so be sure to ask for it if you buy from them.

[Dlg96]

Originally Posted by MooMooM2

I do wonder if this issue would also happen on the smaller blue brakes. From looking at this issue in the past this does not only happen with the BBKs, other people with other brands have had this problem, its more of brake pad material problem vs size it seems so the best answer is to change brake pads? Sure its annoying and costs money but the stock pad is not that great anyways.

I have experienced this vibration before and took to dealer and they didn't do anything for me, which is fine because I realized what it was. It eventually went away and now its bad, its not bad though, I get a tiny vibration at about 50mph when I hit the brakes and then goes away... yall might be experiencing a bigger vibration because this does not bother me too much. Likely happened from taking the car to the track on stock pads.

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It is possible and I've been experiencing this issue with my 2016 M2 since August 2021. At first, I figured since the car had just over 50k miles that the rotors' lifespan was up. I had all four rotors and pads replaced (out of pocket since the warranty had already expired) and after about 500-1000 miles, the issue was back. This next part is going to sound absurd, but I assure you it's true.

BMW has replaced those parts FIVE or SIX times under parts warranty at this point. I literally lost count but it's all in the paperwork. I took it to another dealer and they brought in field techs to evaluate. Found nothing. I took it to a private specialist who told me it could be the front wheel hubs/bearings since BMW used a lightweight (but more fragile) design on the front hubs in particular. So, I had those replaced. The pulsation came back but it took longer than before. I took it back to the same shop and they told me it could be a number of suspension components including a bent/tweaked axle, strut, or knuckle. So the only way to attempt to solve the problem would be to keep throwing parts and money at it. I'm not willing to do that anymore. The shop owner advised me to get rid of the car, of course I can't in good conscience sell it privately. This is clearly a terrible design flaw and a huge oversight on BMW's part. I've tried escalating to BMW NA but to no avail.

I'm not sure what to do next, and I'd hate to lose the car this way. I could trade it in to a dealer and have it be their problem, but again that's not ideal. Whatever the real issue is, it's so slight than an extremely experienced BMW specialist couldn't identify it after multiple attempts. I'm not sure what good posting this here will do, but I feel that people should know about it.

FYI: I purchased the car pre-owned in early 2019 with 25k miles on the clock. I did two track events that year but since then it has been used in mostly normal driving with some occasional mountain road jaunts. It's also been maintained and cared for meticulously. The issue first popped up in August of last year, like I mentioned. There's nothing I can think of that could have directly caused it.

[MooMooM2]

Originally Posted by Dlg96

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It is possible and I've been experiencing this issue with my 2016 M2 since August 2021. At first, I figured since the car had just over 50k miles that the rotors' lifespan was up. I had all four rotors and pads replaced (out of pocket since the warranty had already expired) and after about 500-1000 miles, the issue was back. This next part is going to sound absurd, but I assure you it's true.

BMW has replaced those parts FIVE or SIX times under parts warranty at this point. I literally lost count but it's all in the paperwork. I took it to another dealer and they brought in field techs to evaluate. Found nothing. I took it to a private specialist who told me it could be the front wheel hubs/bearings since BMW used a lightweight (but more fragile) design on the front hubs in particular. So, I had those replaced. The pulsation came back but it took longer than before. I took it back to the same shop and they told me it could be a number of suspension components including a bent/tweaked axle, strut, or knuckle. So the only way to attempt to solve the problem would be to keep throwing parts and money at it. I'm not willing to do that anymore. The shop owner advised me to get rid of the car, of course I can't in good conscience sell it privately. This is clearly a terrible design flaw and a huge oversight on BMW's part. I've tried escalating to BMW NA but to no avail.

I'm not sure what to do next, and I'd hate to lose the car this way. I could trade it in to a dealer and have it be their problem, but again that's not ideal. Whatever the real issue is, it's so slight than an extremely experienced BMW specialist couldn't identify it after multiple attempts. I'm not sure what good posting this here will do, but I feel that people should know about it.

FYI: I purchased the car pre-owned in early 2019 with 25k miles on the clock. I did two track events that year but since then it has been used in mostly normal driving with some occasional mountain road jaunts. It's also been maintained and cared for meticulously. The issue first popped up in August of last year, like I mentioned. There's nothing I can think of that could have directly caused it.

that is really strange but if new pads and rotors did the trick for 1000 miles then it has to either be one or the other? Do you use your ebrake? I stoped using it all together after starting to go the track and learning that using the ebrake when brakes are hot is a no no.

The only thing for you to try is to get some more abrasive pads, aka track pads and run them for a minute and then switch back to stocks and see if the wobbliness is gone.

Mine is back now but it is so subtle that I don't mind it, its just a tiny bit aroudn 40mph. It will eventually go away and come back

[jritt@essex]

Anytime a pad is taken outside of it's intended temperature range, you risk uneven pad deposits on the discs. That's what is happening with the OEM pads. Below is an article I wrote about running OEM pads on the track (which I've seen a lot of people on this forum do!):

Can I Run My OEM Brake Pads on the Racetrack?

Switching across brands for your road and track pad compounds opens up a can of worms for cross-contamination, judder, and vibration. We see it all the time. When you lay down two pad materials that have completely different materials, they often don't play very nice together on the disc face. Rather than seamlessly melding together when they get really hot, they often stack up, gum up, ball, up...whatever you want to call it. They literally turn into a hot mess. The gooped up pad material creates uneven/high spots on the disc face which leads to judder. The only way to prevent that is to scrape the disc faces clean before laying down the other pad material. See the video I made long ago on this topic for an example of how that is done.

The DS2500, DS1.11, DSUNO, DS3.12, etc. are all made from the same core constituent materials. That means they can be laid down over top of each other on the same disc (pad transfer layer) without fears of cross-contamination, judder, vibration, etc. When you switch from one of the Ferodo materials to the other on a set of discs that has already been bedded-in with Ferodo pad material, you just have to do a few moderate stops to get the pads faces seated properly on the discs. Then you're good to go.

Here's a guide we put together on the Ferodo brake pad compounds:

Which Ferodo Brake Pad Compound is Right for Me?

While the pad-swapping scenario can be managed (as shown in the video below), it can be a hassle. You have to frequently scrape and re-bed every time you swap your pads from street to track compounds. That's fine if it's twice a year. If you're going to the track more than that, it can become a real hassle.

The vast majority of our big brake kit customers run the DS2500 for daily driving, autoX, and sometimes even light track duty on street tires, and then swap to the heavy artillery for track time (DS1.11, DS3.12). That combo makes the pad swap pain-free and near effortless regardless of the driving environment. You don't have to worry about finding a safe stretch of road to do the bedding constantly, or wasting track sessions to try and get your discs sorted.

Also, based on a great deal of customer feedback across a wide range of vehicles (Corvettes, Porsches, FT86, Mustangs, Miata, etc.), the Carbotechs seem to be much more finicky than Ferodo when it comes to bedding/burnishing. While we only very rarely hear about judder/vibration issues with Ferodo, we hear about those issues with the various Carbotech pads quite often.

Again, mixing pad compounds from different manufacturers or even different product lines from the same manufacturer can lead to a lot of headaches. We have a lot of enthusiasts coming to us for help to shake their shakes. Sometimes they wind up trashing their discs so bad with uneven pad deposits that the discs can't be saved (as evidenced by those of you in this thread who have had the dealership replace your discs numerous times). Then they're paying for new discs in addition to new pads...not fun, and certainly not worth the small savings on trying to buy a super cheap set of street pads.

ps My input is based on over twenty years of dealing with aftermarket brakes every day of my life, and from twenty+ years of tracking my own personal cars. I have dealt with and sold a huge variety of brake pads from many manufacturers during that time. The Ferodo pad system for road/track (DS2500 + one of their pure racing pads) is by far the least problematic, best performing I have ever seen.


Video on swapping between pad compounds/pad management:

Video on bedding-in discs:

[Figgs_1979]

Check your hydro bearing and caliper bolts

[PackPride85]

The only time I've ever felt vibration going from oem to hawk dtc-60 pads is when i swap to the hawks prior to track day. After a few days doing cold street driving it scrapes off every bit of the oem pad that was on the rotor. Same deal after track day. A day or so on the street and it scrapes clean and no issues with the oem pad going back on.

[JWMII]

Originally Posted by liontomic

Start of this year, I was feeling vibration when braking. Took my car into the dealer, said my brakes are warped and got them replaced under warranty.

4000 miles later, that vibration came back and dealer said they're warped again? And this time it will not be covered by warranty and I'd have to pay 2400 out of pocket

All those 4000 miles were highway/commute miles. I didn't even bother to hit any backroads. Is this even possible? Very disappointed with BMW quality

Yes, on my 5th said of front rotors on my 2019 M2C. BMW has now replace my front rotors 4 times, and front and rear twice. Just picked it up again the day before Thanksgiving with 45,700 on the clock. As I've stated in my previous post on threads I started on this topic, my car has never been tracked, and I use a lot of engine braking since I have a manual. What I was told by service advisor (who said the shop foreman advised him) is that the Meguiars wheel cleaner is the cause of the brakes warping prematurely. I can't believe he told me that. Says that the wax in the cleaner is creating a condition that fools the electronic brakes to stay clamped to the rotors creating over heating. I'm still startled that was the answer they gave me. What can't be argued is that BMW has covered all replacements under my extended warranty so great they did that. I was told to specifically to stop using the Meguiars, but that the BMW wheel cleaner wouldn't create this issue for me. Anyone wanna take bets on this.

[kthor703]

Originally Posted by JWMII

Yes, on my 5th said of front rotors on my 2019 M2C. BMW has now replace my front rotors 4 times, and front and rear twice. Just picked it up again the day before Thanksgiving with 45,700 on the clock. As I've stated in my previous post on threads I started on this topic, my car has never been tracked, and I use a lot of engine braking since I have a manual. What I was told by service advisor (who said the shop foreman advised him) is that the Meguiars wheel cleaner is the cause of the brakes warping prematurely. I can't believe he told me that. Says that the wax in the cleaner is creating a condition that fools the electronic brakes to stay clamped to the rotors creating over heating. I'm still startled that was the answer they gave me. What can't be argued is that BMW has covered all replacements under my extended warranty so great they did that. I was told to specifically to stop using the Meguiars, but that the BMW wheel cleaner wouldn't create this issue for me. Anyone wanna take bets on this.

That is a pretty hilarious claim by them. I'd be incredibly surprised if a wheel cleaner has wax in it. I don't think I know of one that does...

[KevinC]

The issue is pretty simple - the pads are absolutely horrendous for street use. If you use your M2c for daily driver-type duties, you're gonna get deposits on the rotors, which creates the "warped" sensation. I had mine replaced once as a "goodwill" replacement (i.e. not acknowledged as a warranty replacement), and by 4k miles later, same problem on the new ones. After much research on the problem I switched to Carbotech 1521 pads and the problem is solved - and pedal feel consistency is far better too.

[chris719]

Originally Posted by kthor703

That is a pretty hilarious claim by them. I'd be incredibly surprised if a wheel cleaner has wax in it. I don't think I know of one that does...

This is pretty funny. How does the car even know it's wet? I would assume this is from the rain sensing wipers aka front camera. These guys are so dumb to blame it on a wheel cleaner. I'm not aware of any sensor in that area other than the brake wear sensor.

[JWMII]

Originally Posted by KevinC

The issue is pretty simple - the pads are absolutely horrendous for street use. If you use your M2c for daily driver-type duties, you're gonna get deposits on the rotors, which creates the "warped" sensation. I had mine replaced once as a "goodwill" replacement (i.e. not acknowledged as a warranty replacement), and by 4k miles later, same problem on the new ones. After much research on the problem I switched to Carbotech 1521 pads and the problem is solved - and pedal feel consistency is far better too.

So the switch in pads solved the warping issue, but are you having noise issues due to the switch in pads? BMW loves to claim their rotors and pads are developed to be used together for max performance, and switching pads can create braking or noise issues.

[chris719]

Originally Posted by JWMII

So the switch in pads solved the warping issue, but are you having noise issues due to the switch in pads? BMW loves to claim their rotors and pads are developed to be used together for max performance, and switching pads can create braking or noise issues.

Stock M2C brakes already have noise issues .

[JWMII]

Originally Posted by chris719

Stock M2C brakes already have noise issues .

Cant say the noise has been a problem for me.

[KevinC]

Originally Posted by JWMII

So the switch in pads solved the warping issue, but are you having noise issues due to the switch in pads? BMW loves to claim their rotors and pads are developed to be used together for max performance, and switching pads can create braking or noise issues.

BMW makes all kinds of silly claims, like virtually every big company. Remember when runflat tires were first put on virtually everything they make, circa 2006? The marketing department put out some fluff stating that the suspension was "tuned for runflats". Sure - they softened the damn suspension bushings to try to alleviate the crashing/harsh ride quality the ultra-stiff sidewalls was causing. Didn't help much. Thankfully for those suffering with these turds nowadays, they've gradually gotten better. Those early ones were brutal.

Back to the topic at hand - the rotors aren't getting warped, it's the deposits. I'm convinced this article is accurate in our situation...

https://alconkits.com/support/brake-...d-brake-rotors

[chris719]

Originally Posted by JWMII

Cant say the noise has been a problem for me.

OEM pads? I've driven 3 M2C and they all squeal when warm on light braking. I wouldn't call it a problem, but they aren't quiet.

[JWMII]

Originally Posted by KevinC

BMW makes all kinds of silly claims, like virtually every big company. Remember when runflat tires were first put on virtually everything they make, circa 2006? The marketing department put out some fluff stating that the suspension was "tuned for runflats". Sure - they softened the damn suspension bushings to try to alleviate the crashing/harsh ride quality the ultra-stiff sidewalls was causing. Didn't help much. Thankfully for those suffering with these turds nowadays, they've gradually gotten better. Those early ones were brutal.

Back to the topic at hand - the rotors aren't getting warped, it's the deposits. I'm convinced this article is accurate in our situation...

https://alconkits.com/support/brake-...d-brake-rotors

Thanks for the info. Did you swap out the rotors when you switched to another pad?

[MooMooM2]

Originally Posted by chris719

OEM pads? I've driven 3 M2C and they all squeal when warm on light braking. I wouldn't call it a problem, but they aren't quiet.

They really have not been noisy at all for me, sure once in a while a little squeel but not bad at all. I wonder why some people have so much problems with this and some don't

[chris719]

Originally Posted by MooMooM2

They really have not been noisy at all for me, sure once in a while a little squeel but not bad at all. I wonder why some people have so much problems with this and some don't

Do you do a lot of city driving? That’s where I notice it most.