[SlumsToMills]

Hello All,

Ive heard good things about r1 concepts rotors and pads. However my first order of these front carbon geomet series for my 2013 335i m sport is making me feel otherwise. Seems like I got a horrible batch full of possible faults.
Is this normal? It doesnt seem so.
The workmanship and quality seems off as well.
These are suppose to be drilled but it looks like they are only partially drilled and not all the way? these are front rotors btw.
Theres a crack and why does one rotor have a groove and the other doesn't?
The vented layer has unfinished or manufacture defects as well.

Looks like they are headquartered nearby me in Cerritos so i hope i can go by their place and do a quick exchange because this is horrible.

Pics below:

[johnung]

Originally Posted by SlumsToMills

Hello All,

Ive heard good things about r1 concepts rotors and pads. However my first order of these front carbon geomet series for my 2013 335i m sport is making me feel otherwise. Seems like I got a horrible batch full of possible faults.
Is this normal? It doesnt seem so.
The workmanship and quality seems off as well.
These are suppose to be drilled but it looks like they are only partially drilled and not all the way? these are front rotors btw.
Theres a crack and why does one rotor have a groove and the other doesn't?
The vented layer has unfinished or manufacture defects as well.

Looks like they are headquartered nearby me in Cerritos so i hope i can go by their place and do a quick exchange because this is horrible.

Pics below:
[img]https://i.ibb.co/0XKFGrN/2251-EA61-BF8-C-4746-AF46-8-F3737-C7-AA0-A.jpg[/img] [img]https://i.ibb.co/sFRndMw/IMG-1467.jpg[/img] [img]https://i.ibb.co/mXCCDNL/4-CAFB623-4682-441-E-A70-E-421723-A1513-B.jpg[/img] [img]https://i.ibb.co/vYgdJkJ/IMG-1468.jpg[/img] [img]https://i.ibb.co/fdk9dJG/IMG-1469.jpg[/img] [img]https://i.ibb.co/QHPDd76/IMG-1470.jpg[/img] [img]https://i.ibb.co/RP6PCcy/IMG-1472.jpg[/img] [img]https://i.ibb.co/TBC64yG/IMG-1473.jpg[/img] [img]https://i.ibb.co/wz5WKrx/IMG-1475.jpg[/img]

R1 doesn’t really have a good reputation. They sell crap overseas stuff and poor their money into slick marketing to sell lots of it. Return them and get your money back. You are very lucky that they are local rather than return shipping costs and dealing with them over the phone.

Avoid R1 Concepts, PowerStop, etc. all slicked up junk.

Avoid those dimpled rotors which are noisy. Use either plain rotors or full crossdrilled like BMW puts on their M2/M3/M4 cars. The dimpled & slotted rotors for the F3x are BMW Marketing gimics. They would never put them on M cars.

Avoid brake “kits”. They know that you are buying on price so kits will contain junk to get price down and their profits up.

Buy Hawk 5.0 pads and either Zimmermann plain rotors or StopTech full crossdrilled rotors.

[SlumsToMills]

Originally Posted by johnung

R1 doesn’t really have a good reputation. They sell crap overseas stuff and poor their money into slick marketing to sell lots of it. Return them and get your money back. You are very lucky that they are local rather than return shipping costs and dealing with them over the phone.

Avoid R1 Concepts, PowerStop, etc. all slicked up junk.

Avoid those dimpled rotors which are noisy. Use either plain rotors or full crossdrilled like BMW puts on their M2/M3/M4 cars. The dimpled & slotted rotors for the F3x are BMW Marketing gimics. They would never put them on M cars.

Avoid brake “kits”. They know that you are buying on price so kits will contain junk to get price down and their profits up.

Buy Hawk 5.0 pads and either Zimmermann plain rotors or StopTech full crossdrilled rotors.

thank you for your input.
Interesting your comment about dimpled rotors. Zimmerman has dimpled rotors too. https://www.fcpeuro.com/products/bmw...nn-34106797602

you would think dimpled rotors were tested why else would they be selling these?

[johnung]

Originally Posted by SlumsToMills

thank you for your input.
Interesting your comment about dimpled rotors. Zimmerman has dimpled rotors too. https://www.fcpeuro.com/products/bmw...nn-34106797602

you would think dimpled rotors were tested why else would they be selling these?

Zimmermann sells OEM rotors for every rotor that BMW sells, so of course they sell dimpled & slotted. Like I said they are basically a BMW Marketing scam on F30 owners. They include them with the F30 M Performance Brake Kit to give the false impression that they are something special.

Whoever dreamed it up at BMW made the company a fortune. The proof that there is no engineering advantage to dimpled/slotted is that BMW never puts them on an M car. M cars get full crossdrilled rotors standard. Many other makes do the same on their high performance street models including Porsche, Mercedes, McLaren, etc.

[Watsey]

Originally Posted by johnung

Zimmermann sells OEM rotors for every rotor that BMW sells, so of course they sell dimpled & slotted. Like I said they are basically a BMW Marketing scam on F30 owners. They include them with the F30 M Performance Brake Kit to give the false impression that they are something special.

Whoever dreamed it up at BMW made the company a fortune. The proof that there is no engineering advantage to dimpled/slotted is that BMW never puts them on an M car. M cars get full crossdrilled rotors standard. Many other makes do the same on their high performance street models including Porsche, Mercedes, McLaren, etc.

Agreed.

Cross-drilled and grooved discs each have their benefits. Dimpled is just for aesthetics.

[cfm56d7b]

Dimpled rotors included in M Performance brake kit are technically misplaced but then again - marketing team often has the last word.

Dimpled rotors were originally developed for heavier vehicles due to much higher load and stress on the brake rotors. The rotors with dimples (or round cavities) provide nearly identical structural integrity as smooth rotors.

Under heavy load and stress (towing, frequent stops) there is more heat and at some point the brake pad begins to literally melt, breaking down binding resins and producing gas: or - commonly known as outgassing.

Outgassing leads to a thin layer of gas forming between the pad surface area and the rotor surface area, preventing the full contact.

Dimples rotors allow the brake pad to "breathe" and release the gas. With each rotor revolution, the trapped gas is generated and released. M Performance brakes with dimpled rotors receive many noise complaints from owners. The noise is entirely normal. As the gas is trapped and released it pushes on the brake pad with pulsating energy.

So dimpled rotors have a place in automotive engineering, just not in lighter cars where the cross-drilled rotors offer the same outgassing functions with a better cooling capability.

Slotted rotors, especially J-hook rotors from AP Racing, are a much better choice than dimpled rotors.

https://www.essexparts.com/brake-dis...on-brake-discs

PS. Find myself in complete agreement with johnung about R1 rotors impressions.

[r1concepts]

Originally Posted by SlumsToMills

Hello All,

Ive heard good things about r1 concepts rotors and pads. However my first order of these front carbon geomet series for my 2013 335i m sport is making me feel otherwise. Seems like I got a horrible batch full of possible faults.
Is this normal? It doesnt seem so.
The workmanship and quality seems off as well.
These are suppose to be drilled but it looks like they are only partially drilled and not all the way? these are front rotors btw.
Theres a crack and why does one rotor have a groove and the other doesn't?
The vented layer has unfinished or manufacture defects as well.

Looks like they are headquartered nearby me in Cerritos so i hope i can go by their place and do a quick exchange because this is horrible.

Pics below:

I am one of the reps here at R1. First of all, that rotor(s) should have definitely not been shipped out to you in that condition. It looks like it got scratched/chipped during the machining process as they were being dimpled. Please contact our customer service department and they should be able to help you to get you replacements.

As for why it can't be drilled completely through the rotor, this is because of the internal vane structure of this specific rotor. If we were to drill completely through the rotors, we would damage the internal vane structure. Because of this, unfortunately we're only able to dimple these rotors even though you purchased drilled rotors. BMW does also offers dimpled & slotted rotors and not sure why they still do this. Any rotor with dimpled holes are mainly just for aesthetics.