Are all StopTech 355x32 Rotor Rings the same and would fit a Brembo GT kit?

[bmw m3 s50]

I need to replace a set of 355x32 slotted rotor rings for my Brembo GT 355x32 BBK kit and came across someone who is selling a set for a really good deal. The issue is I was researching part numbers and saw that there are two different part numbers?

The part numbers on the rotors that are for sale are:

Stoptech 31.737.1102.87 for the Front Right Slotted 355x32mm rotor ring

and

Stoptech 31.737.1101.87 for the Front Left Slotted 355x32mm rotor ring



When I was researching through different sites just as Bimmerworld, the right rotor has the same part number:

• SRT31.737.1102.87

https://www.bimmerworld.com/Brakes/B...tion-Ring.html

but the left side has a different part number

• SRT31.737.1101.99

https://www.bimmerworld.com/Brakes/B...ted-Rotor.html


The seller keeping swearing that it's the same and will work on my Brembo GT but since it's a private sale, I want to be sure that these rotor rings would work. Does anyone have any info on this?

[Slideways]

https://www.zeckhausen.com/catalog/index.php?cPath=24_212_511&osCsid=5a4gvmgasm8ebfc3sr5ki8h2f0

87 has Max float hardware race only

99 has standard hardware

Rotor rings are probably the same, but different hardware

[bmw m3 s50]

https://www.zeckhausen.com/catalog/i...bfc3sr5ki8h2f0

87 has Max float hardware race only

99 has standard hardware

Rotor rings are probably the same, but different hardware

Damn, that explains it. Thank you. I was on zeckhausen's site but could not find that page that you posted.

You don't think that the rotors are different to accommodate the Max float hardware?

[Slideways]

Damn, that explains it. Thank you. I was on zeckhausen's site but could not find that page that you posted.

You don't think that the rotors are different to accommodate the Max float hardware?

No. Based on the part numbers, first three sets of numbers identify rotor type (drilled or slotted) and last set is for hardware. Can always contact them to verify.

[bmw m3 s50]

No. Based on the part numbers, first three sets of numbers identify rotor type (drilled or slotted) and last set is for hardware. Can always contact them to verify.

That actually makes sense.

Damn, this sucks that these rotors have the Max Float instead of the regular hardware. If I have to buy the regular hardware it would negate the deal that I am getting.

Thank you once again for the info.

[mrgizmo04]

Here is a good page for which sizes are directly interchangeable vs which require machining:

https://www.zeckhausen.com/catalog/index.php?cPath=82_1516

Also, the hardware can be reused with some green loctite.



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[bigjae46]

I think Girodisc sells the same 355mm rotor for Brembo's and Stoptechs. So it would be safe to say that the holes for the hats and rings would line up. Not familiar with max float hardware so can't say whether that makes a difference.

Also makes sense the bolt holes would be equidistant from each other. Another indication is if the bolt count is the same.

[bmw m3 s50]

Here is a good page for which sizes are directly interchangeable vs which require machining:

https://www.zeckhausen.com/catalog/index.php?cPath=82_1516

Also, the hardware can be reused with some green loctite.



Sent from my SM-S911U1 using Tapatalk

I saw that link too, Thank you.

Ehhh, I agree green Loctite could be used but I am a little wary on reusing brake rotor hardware where every manufacturer requires new hardware on rotor ring swaps.

[bmw m3 s50]

I think Girodisc sells the same 355mm rotor for Brembo's and Stoptechs. So it would be safe to say that the holes for the hats and rings would line up. Not familiar with max float hardware so can't say whether that makes a difference.

Also makes sense the bolt holes would be equidistant from each other. Another indication is if the bolt count is the same.

Yeah, I saw that. I found a set of Stoptech rotor rings through a private seller that use the max float hardware. The Max Float hardware is intended for track use as they cause they use full-float flat washers that allow 0.4mm axial float, with no anti-rattle function. The standard hardware use semi-float conical washers to allow for some axial float, while maintaining a spring force to minimize vibration and noise. Simply put, the Max Float is going to cause a lot more braking noise compared to the standard hardware which may not be a problem for a track car but more of an annoyance issue on a street car.

[Obioban]

I tried the stop tech rings on my Brembo kit one time. They lasted ~20% as long as the brembo rings, so seemed a false economy-- went back to brembo the following time.

[liam821]

I tried the stop tech rings on my Brembo kit one time. They lasted ~20% as long as the brembo rings, so seemed a false economy-- went back to brembo the following time.

I replaced my Brembos with Stoptechs as well and noticed no uneven or bad wear, although I never tracked mine. Although I only got a few thousand miles on them until I sold them they looked new when I removed them from the car.

[WestBankM4]

I too have the Brembo GT's 355mm on the front and 345mm on the rear. I replaced all the hubs and the discs on mine, I went with GiroDisc for the rotors, direct plug and play. So far so good, they're wearing evenly.

Question, what's the pads you're using for the Brembo GT kit, spirited driving for the streets/canyons?

[bmw m3 s50]

I tried the stop tech rings on my Brembo kit one time. They lasted ~20% as long as the brembo rings, so seemed a false economy-- went back to brembo the following time.

I would agree that the Brembo product would be of higher quality thus providing longer life span. I was getting a really good deal below retail pricing which is why I was considering it.

[bmw m3 s50]

I too have the Brembo GT's 355mm on the front and 345mm on the rear. I replaced all the hubs and the discs on mine, I went with GiroDisc for the rotors, direct plug and play. So far so good, they're wearing evenly.

Question, what's the pads you're using for the Brembo GT kit, spirited driving for the streets/canyons?

I am curious to know which pads to get for the same type of driving conditions. I like a good initial bite on braking and obviously something that doesn't fade, cause a lot noise or dust.

I may be asking for the impossible, hahaha.

[bigjae46]

I tried the stop tech rings on my Brembo kit one time. They lasted ~20% as long as the brembo rings, so seemed a false economy-- went back to brembo the following time.

Something is wrong because my Stoptech rings have lasted 70 track days on the front and another 35 and counting on the rear. I use a fairly rotor unfriendly pad.