Stoptech messed up big time with their wide annulus rotor

[jim1013yyf]

TL;DR - there is no proper sized race pad for the wide annulus (62mm) rotor from the new Stoptech trophy kit.


I ordered a gen5 Stoptech Trophy kit (STR60) from Buybrakes in Dec 2020. After a long wait, I finally received them in early April. During my search for a track pad to go along with this kit, Adam from Buybrakes told me that the kit comes with wide annulus rotor with a friction ring width of 62mm.

While knowing using narrower pad on the wide rotor is okay, I still want to use properly-matched/sized pad. so based on the recommendation from the retailer, I went with Stoptech SR33 wide annulus version, part #333.8W11.18.0 (notice - this is not the regular SR33 for ST60 which has a part #333.8011.18.0).

But after installing everything, I found out the alleged wide pad is still much narrower than the wide annulus rotor - there is a ~10mm gap between the inner edge of the pad and the rotor hat. See pic below:

View post on imgur.com

So Adam from buybrake passed this issue to Stoptech. And we just received a response from Stoptech -
"We do not carry a wide annulus race friction for the ST60. Okay to use the narrow annulus race version, higher effective radius for now. We are planning to swith the race versoins of the wide annulus systems to 380x35 normal annulus rotor."

This is completely BS since the street pad that comes with the kit are wider pad at 61mm, as I measured

View post on imgur.com

but the alleged wider SR33 is only at 54mm

View post on imgur.com

So am I supposed to use two sets of pads of different sizes? this answer from ST is completed unacceptable. I think the only right option for me right now is to purchase another set of street pad with narrower width so that both street and race pads have same sweeping area....Should've spent a little more $$ and go for AP...

[dvq]

Originally Posted by jim1013yyf

TL;DR - there is no proper sized race pad for the wide annulus (62mm) rotor from the new Stoptech trophy kit.


I ordered a gen5 Stoptech Trophy kit (STR60) from Buybrakes in Dec 2020. After a long wait, I finally received them in early April. During my search for a track pad to go along with this kit, Adam from Buybrakes told me that the kit comes with wide annulus rotor with a friction ring width of 62mm.

While knowing using narrower pad on the wide rotor is okay, I still want to use properly-matched/sized pad. so based on the recommendation from the retailer, I went with Stoptech SR33 wide annulus version, part #333.8W11.18.0 (notice - this is not the regular SR33 for ST60 which has a part #333.8011.18.0).

But after installing everything, I found out the alleged wide pad is still much narrower than the wide annulus rotor - there is a ~10mm gap between the inner edge of the pad and the rotor hat. See pic below:

View post on imgur.com

So Adam from buybrake passed this issue to Stoptech. And we just received a response from Stoptech -
"We do not carry a wide annulus race friction for the ST60. Okay to use the narrow annulus race version, higher effective radius for now. We are planning to swith the race versoins of the wide annulus systems to 380x35 normal annulus rotor."

This is completely BS since the street pad that comes with the kit are wider pad at 61mm, as I measured

View post on imgur.com

but the alleged wider SR33 is only at 54mm

View post on imgur.com

So am I supposed to use two sets of pads of different sizes? this answer from ST is completed unacceptable. I think the only right option for me right now is to purchase another set of street pad with narrower width so that both street and race pads have same sweeping area....Should've spent a little more $$ and go for AP...

This is ridiculous…

[drroc]

Did you guys check if hawk or anybody else makes a race 62mm pad? I kept meaning to look this up, but I just didn't have the time.

[drroc]

https://www.hawkperformance.com/part...perSize=338868
Looks like Hawk doesn't make the wide annulus version of the pad.

[ICTZHP]

Check with Porterfield Brakes in Costa Mesa, CA. If you have the shape, they will make pads for you using your choice of friction material. We went this route on our 2013 F30 335 before track pads were available for the M Performance brakes.

[CSM3]

Adding to the post above. I had Carbotech XP20 pads made for my OEM ceramic calipers on Girodisc Iron Rotors, and they were AMAZING - IMO better than the PFC 08s i had on another track car.

Do note, they squeal a fair bit, and dust a lot (dust was easy to clean). I went through Ken at KNS Brakes and he was great!

[jim1013yyf]

Originally Posted by CSM3

Adding to the post above. I had Carbotech XP20 pads made for my OEM ceramic calipers on Girodisc Iron Rotors, and they were AMAZING - IMO better than the PFC 08s i had on another track car.

Do note, they squeal a fair bit, and dust a lot (dust was easy to clean). I went through Ken at KNS Brakes and he was great!

Oh I didn't know carbotech can do that. I used Xp10 on my E92 M3. Loved them. I currently have PFC08 on the F82, they squeal like crazy (much worse than pagid rs29 or ct xp10) but man they last long!

[jim1013yyf]

Originally Posted by ICTZHP

Check with Porterfield Brakes in Costa Mesa, CA. If you have the shape, they will make pads for you using your choice of friction material. We went this route on our 2013 F30 335 before track pads were available for the M Performance brakes.

Good to know that! Will reach out to see if Stoptech cannot resolve this problem. Is there a tailoring fee?

[jim1013yyf]

Originally Posted by drroc

https://www.hawkperformance.com/part...perSize=338868
Looks like Hawk doesn't make the wide annulus version of the pad.

yes - i think you are right. I remember we were talking about using DTC70 wide version. But I couldn't find it back then..

[icegrill]

Sounds like not a big enough annulus is the problem 😂🤦*♂️

[dvq]

I sent them the following and hopefully they call me back with a response:

Hi,

I've purchased a full set of BMW F8X (2015-2020 M3/M4) through one of your vendors (BuyBrakes) and waited months to get my kit in. I was convinced that this full kit was a fantastic slightly lower-cost alternative to going with AP Racing. I was so convinced that I convinced 3 others to buy full kits as well.

However, I've come to realize there are issues with how your kit is packaged with the front rotors being wide annulus. I ordered a set of race calipers which were pieced together with SR34/SR33 pads as well as an extra set of 309 front and rear pads. However, this has been a complete nightmare due to mismatched annulus widths. This makes swapping from street or track impossible with your pads.

- 309s came in ~61mm annulus which matched the rotor and I installed.
- SR34 came in standard annulus so I sent them back to you guys for a set of SR33 which were wide annulus.
- SR33 exchange I received weren't standard OR 61mm annulus but instead is 54mm annulus.

So I'm reaching out to you to see what solutions you have for me after spending well over $6K on brakes seeing as I thought I'd have pad selection from multiple mfg, but instead, I don't even have pad selection from your own company.

Should I be:
Converting everything back over to standard annulus? If so at my own cost?
Needing separate front road and track hats/rotors?
Expecting pads made for the kits that you provide?

A little bit frustrated here, please let me know what we can do to actually make these 4 full trophy kits work because I'm starting to think we should have all been better off buying from your competitor AP Racing.

[drroc]

Originally Posted by dvq

I sent them the following and hopefully they call me back with a response:

So a data point. I have swapped back to the regular wide street pads, and the the brakes felt like shit. This is mainly because the Hawk race pads really shaved the rotor and the street pad were not quite flush. After driving for a bit things became better. I assume this is because the the street wide pad got deformed to fit the new shape of the rotor. I probably need to take the car to a local back road to bed in the pad again. The main take away is that if you swap from standard race pad to a wide street pad, the brakes will feel like shit because the pad can't make good contact with the rotor. From a safety stand point, it is better to just run same sized race and street pads.

[jim1013yyf]

Originally Posted by dvq

I sent them the following and hopefully they call me back with a response:

Originally Posted by dvq

I sent them the following and hopefully they call me back with a response:

thanks for the update - I've also emailed stoptech directly but they replied to Adam@buybrakes. I have an ongoing conversation with Adam regarding this issue.

Quote from Adam "I have the owner here digging in with the VP at Stoptech, fyi....not sure when but they're going to discuss any potential solution for the WA rotor/pad issue"

[dvq]

Originally Posted by jim1013yyf

thanks for the update - I've also emailed stoptech directly but they replied to Adam@buybrakes. I have an ongoing conversation with Adam regarding this issue.

Quote from Adam "I have the owner here digging in with the VP at Stoptech, fyi....not sure when but they're going to discuss any potential solution for the WA rotor/pad issue"

I have a resolution for pads from the engineers at Stoptech, they're gonna make pad selection for us and would like to work with us to test new pad compounds for the wide annulus front kit on the f8x. DM me if you aren't already in contact with Stoptech

[jpy1980]

Originally Posted by CSM3

Adding to the post above. I had Carbotech XP20 pads made for my OEM ceramic calipers on Girodisc Iron Rotors, and they were AMAZING - IMO better than the PFC 08s i had on another track car.

Do note, they squeal a fair bit, and dust a lot (dust was easy to clean). I went through Ken at KNS Brakes and he was great!

+1 for Ken at KNS!

[drroc]

Originally Posted by dvq

I have a resolution for pads from the engineers at Stoptech, they're gonna make pad selection for us and would like to work with us to test new pad compounds for the wide annulus front kit on the f8x. DM me if you aren't already in contact with Stoptech

I "DM"ed you. I was bitching to Adam about this, but then I got side tracked with a bunch of work and kid stuff...

Edit: If StopTech can make a wide pad with a Hawk DTC70 like compound, that would be freaking awesome.

[jim1013yyf]

follow up on this old post - as of today(sept 9th of 2021) there still isn't a true wide annulus race pad (62mm pad depth) on the market.

[RSXDC5]

Originally Posted by jim1013yyf

follow up on this old post - as of today(sept 9th of 2021) there still isn't a true wide annulus race pad (62mm pad depth) on the market.

Wow.

Do you have the Stoptech FMSI # for their pad shapes (f/r)? You can take those FMSI #s to a brake pad manufacturer and they can accommodate you.

[jim1013yyf]

Originally Posted by RSXDC5

Wow.

Do you have the Stoptech FMSI # for their pad shapes (f/r)? You can take those FMSI #s to a brake pad manufacturer and they can accommodate you.

yes according to stoptech and the vendor, the new FMSI# for the wide-annulus rotor is DR35 (instead of the DR11). But the problem came as I was double checking the size of DR35, and found out that it was 54mm.... so there is no actual FMSI# for the 62mm pad that they sent out with the kit.. at least they are not posted anywhere.

[RSXDC5]

Originally Posted by jim1013yyf

yes according to stoptech and the vendor, the new FMSI# for the wide-annulus rotor is DR35 (instead of the DR11). But the problem came as I was double checking the size of DR35, and found out that it was 54mm.... so there is no actual FMSI# for the 62mm pad that they sent out with the kit.. at least they are not posted anywhere.

Take measurements of the 62mm pad and take that to your brake pad manufacturer, they will most likely have something that works for u. Good luck!

[drroc]

https://knsbrakes.com/c/caliper-seri...P20+Brake+Pads

This is the pad to get. I didn't have a chance to test it out, but I heard from another member that it worked great at Laguna.

[Jims M3]

I had this issue too, I ended up using the regular pads for the ST-60 but I did find out that Pagid does make a yellow compound wide annulus pad for this kit.