Anyone tested RB Performance Rotors?

[pbonsalb]

That is great well great unsparing weight savings! Twice the price of stock but people often pay a lot to save weight.

[tdott]

Interesting keep us posted, try to get some pictures once you have them installed.

Thanks,

[aswy6]

So these are direct replacement for our E92 M3 stock rear breaks? Very interesting! Wanna see pics and feedback from installation. My breaks are due for a change

[Richbot]

Well, the rears fit, sorta. I think there may be a parts update/backdate issue. The rotor hits my 3/30/08 build's caliper bracket on the outside, it needs like 1mm of extra clearance if that, it will still roll just only with engine power, heh. I was 100% sure I had managed to lock the ebrake on and spent a while troubleshooting that it never occurred to me that they would have gotten the fitment a bit off. But as soon as I started taking things apart it became clear the rotor is hitting the bracket. I would think maybe something is bent back there but it's the exact same clearance issue on both sides so I doubt it.

Emailed RB to see if they have any ideas. Replacement rear bracket ordered, the replacement appears to have more machined surfaces than mine, the photos online I'm finding show no nubbin where mine has nubbins, for instance. If I had a machine shop fly cut about 2mm off the outside I'd be in business, and I may still do that depending on RB's response, but I'd prefer to let them try and figure it out.

[Richbot]

RB has already gotten back to me, Sunday customer service is a plus. We’ll see how it shakes out.

[Visceral]

I also can't easily accommodate the 2mm thicker-than-stock rotors. It is also slightly offset to the outside by about .5 mm, making the situation more difficult. I can either:

1. Order 16.5mm thick pads from now on.
2. Only use slightly worn 18.5mm pads.

Oh yeah, I have a Brembo sorta-BBK and F80 RB rotors, so I'm hacking already.

But the extra 2mm above stock rotor thickness and the .5mm outward offset didn't help. Fortunately the local BMW had a good deal for BMWCCA members on stock F80 M3 rotors.

[Richbot]

The pads fit fine in my case the stock floating rear calipers have plenty of room. The rotor itself is physically interfering with the bracket.

I think they must have misjudged where the centers of stock bmw rotors are just that little bit if yours are also offset slightly.

[Richbot]

Replacement set on the way, they say. So far service has been very good despite my obvious frustration over email.

[Richbot]

Update: replacement rotors don’t fit either. These need some material removed from the stock caliper bracket/pad carrier to fit. Looking at options now. They have not gotten back to me on my proposed solution.

For now I’m running my ECS rotors (which are at 23.2mm, so only halfway to
Minimum thickness after 45k miles) with another set of stock pads and hoping they respond to my email.

[derbo]

Originally Posted by Richbot

Update: replacement rotors don’t fit either. These need some material removed from the stock caliper bracket/pad carrier to fit. Looking at options now. They have not gotten back to me on my proposed solution.

For now I’m running my ECS rotors (which are at 23.2mm, so only halfway to
Minimum thickness after 45k miles) with another set of stock pads and hoping they respond to my email.

Thank you for beta testing with them.

[Richbot]

RB is telling me they're going to order an OEM bracket and get this sorted on their end for me, so that's good news. Having the brackets machined may end up being part of the standard install procedure for these, who knows. Will update.

[Richbot]

Alright, so, WAyne got involved (thanks Wayne) and RB thinks they found the issue, somehow the wrong upright was used to set up dimensions for the rear E9xM hats they sent me, which threw things off by just enough to cause issues but not enough to find before shipping, so they ordered a new upright and bracket and have test-fit on their test rig and are sending me new ones right meow.

So, anyway, will let y'all know what happens when I try and slap em on. Here's still hoping for -7lb from the rotating bits with no downsides...

[Richbot]

So, problem solved. They fit and are brake rotors. Will report back once I have some miles on them and a chance to get them bedded properly later today hopefully

About 3lb lighter per side than worn ECS rotors, with 54 vanes compared to 36 on the ECS and 30 on the stock rotors, if you want to call what's on the inside of the stock rotors "vanes".

I had just adjusted the ebrake, but the ebrake is working fine too, so the iron friction ring for the ebrake is in the right spot and working as it should.

I still have some reservations about how this all played out, the product itself appears to be fine now but there were some red flags. Those red flags have stopped waving but I can't ignore them and still be faithful to the reportage.

So, caveat emptor.

But as this is the only game in town for light replacement rear rotors for this car, I'm glad the beta test ended in a good result, and if you want an upgraded rear rotor for your E9xM without any caliper changes/BBK, the RB rears are the lightest option short of something very custom and very expensive.

[derbo]

Thank you Richbot !

Do you have any pictures of the installed rotors? Keep us updated on how it performs with some mileage!

[Richbot]

Potatophone after bedding during a mental health break:

[SYT_Shadow]

thanks for being our test bunny

[Richbot]

Update: Drove to work. Car stopped in time to not take out the parking garage

I think they will continue to be brake rotors. ALSO + 5mpg and 10mph in the 1/4 because of the weight loss, GPS verified and EPA certified

One sorta design/daily driver note: These have the usual because-racecar rotor setup of a nice big open area between hub and rotor hat which makes for nice big gap for nice cool air to be pumped through, but that also means using them in a "Real" winter would probably mean the ebrake gets more salt/crap in it.

I daily mine but don't use mine like that, it never sees the slush or salt and just sits in the garage while I drive the truck during our salty month(s), so I don't care, but you might

Next stop - Karbonius and carbon roof, not necessarily in that order BECAUSE SOMEBODY IN THIS THREAD'S BROKEN JUNK STILL HASN'T BEEN ON THE DYNO

[SYT_Shadow]

Who is this person you speak of?

[derbo]

Originally Posted by SYT_Shadow

Who is this person you speak of?

I think it's a ghost

[SYT_Shadow]

Do we know why their rotors are thicker than OEM? This sounds like a massive PITA, as I want to use PFC rear pads if I get these things and refuse to spend my days grinding pad material

[Richbot]

My unscientific observation was the RB pads included with the rear rotors were the same thickness both friction material and backing plate as new OEM pads I also had, but did not have the polymer noise-reduction backing on them. I bet most aftermarket pads don't have that backing. The OEM pads fit, but just barely (like tight enough that they would have dragged) so I used the RB's, which are a tame street compound, for now.

as for why, can't say, but I'd bet they didn't want to make a new casting just to make a 24mm friction ring and already had a 350x26mm ring for some other apps (looks like they use this dimension ring in some other BMW and merc apps, maybe the Ford Raptor?) based on their website obviously.

It fits fine now. I did not make any changes to the passenger side bracket, the driver's side is filed down because I was trying to make it work, but in the end the hats they originally sent me were off by about 2.5-3mm and no amount of filing was going to fix it. They (I assume) have fixed the drawings/design control issue, because the set I have on the car now fit fine first try.

As for days grinding brake material - belt sander and a brick? Neighbor kid?

EDIT: Warren tells me I got the one and only set of assembled rotors that shipped like this, due to some internal design changes they made to their BMW lineup which happened to be in progress when mine shipped. So, fluke, hopefully. And like I said, the set I just got back from them fit first try no problem. The hats on my car now have a different part number from those RB shipped originally.

[aswy6]

Originally Posted by Richbot

Update: Drove to work. Car stopped in time to not take out the parking garage

I think they will continue to be brake rotors. ALSO + 5mpg and 10mph in the 1/4 because of the weight loss, GPS verified and EPA certified

One sorta design/daily driver note: These have the usual because-racecar rotor setup of a nice big open area between hub and rotor hat which makes for nice big gap for nice cool air to be pumped through, but that also means using them in a "Real" winter would probably mean the ebrake gets more salt/crap in it.

I daily mine but don't use mine like that, it never sees the slush or salt and just sits in the garage while I drive the truck during our salty month(s), so I don't care, but you might

Next stop - Karbonius and carbon roof, not necessarily in that order BECAUSE SOMEBODY IN THIS THREAD'S BROKEN JUNK STILL HASN'T BEEN ON THE DYNO

Sorry but i dont buy it. MPG is subjective and there are too many variable and accounting for all of them is impossible. 10mph in 1/4 mile equals to 100whp, i dont buy it either. Not trying to offend you but those numbers are just way too over exaggerated.