Nerding out on Brakes shall we? Not another tech deraliment

notthatbryan
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Acworth, GA, USA
1/29/2025 3:32am
sspomer wrote:
i'll delete if already posted, but sram non-circular brake piston patent? is this new? https://patents.google.com/patent/DE102024102985A1/en?assignee=Sram%2c+Llc&before=priority:20250101&after=priority:20230101&sort=new

i'll delete if already posted, but sram non-circular brake piston patent? is this new? 

https://patents.google.com/patent/DE102024102985A1/en?assignee=Sram%2c+Llc&before=priority:20250101&after=priority:20230101&sort=new

Screen Shot 2025-01-28 at 4.30.10 PM.png?VersionId=r

There has to be a reason pretty much all brake calipers use round pistons. 

1
Primoz
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1/29/2025 3:44am

It's easy to get seals. And round pegs in round holes seal the best as the pressure is constant around the perimeter. 

3
Finkill
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GB
1/29/2025 4:06am

I think Formula started that they had issues with the oval pistons not moving evenly (wonky) due to the seal force not being even all the way around the piston. Round seals have even force. 

I have a set of Formula RO brakes that I inherited, which have the oval pistons. I need to find the time to rebuild them and see how they perform. 

3
HexonJuan
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407
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1/29/2025 6:55am
sspomer wrote:
i'll delete if already posted, but sram non-circular brake piston patent? is this new? https://patents.google.com/patent/DE102024102985A1/en?assignee=Sram%2c+Llc&before=priority:20250101&after=priority:20230101&sort=new

i'll delete if already posted, but sram non-circular brake piston patent? is this new? 

https://patents.google.com/patent/DE102024102985A1/en?assignee=Sram%2c+Llc&before=priority:20250101&after=priority:20230101&sort=new

Screen Shot 2025-01-28 at 4.30.10 PM.png?VersionId=r

There has to be a reason pretty much all brake calipers use round pistons. 

Yup, manufacturability. I'll also wager that a square seal won't roll quite uniformly so retraction and leakage may be real issues. 

Eae903
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Fantasy
1/29/2025 8:32am
Placek wrote:
Eae903 jasbushey SilentGGentlemen,I didn’t expect so much consensus on Formula. I admit that this setup wasn’t on my radar due to its relatively low...

Eae903 jasbushey SilentG

Gentlemen,
I didn’t expect so much consensus on Formula. I admit that this setup wasn’t on my radar due to its relatively low popularity, actually very little popularity - wondering why?.
I prefer the brake lever to sit relatively far from the handlebars, so that shouldn’t be an issue here. However, I’m curious about the braking power you’ve mentioned as being moderate—will they be weaker than Shimano?
Additionally, how would you rate their performance in terms of lever smoothness, ease of operation, and maintenance?

 

I don't find them weaker than Shimano at all, and in Europe, they are a lot more popular. The US brake market is a lot more limited then Europe, we don't really see anything OEM other than Sram or Shimano, with trp/tektro thrown on some lower end bikes occasionally. They bleed easily, and are very consistent. They just have a different feel than Shimano, I think they sit between the Hayes Dominions and Sram codes in terms of feel, more positive contact than the Sram, and less squishy once there is contact, but a slightly heavier free stroke than the Dominions. It was a brake that I jumped on and immediately got along with. I definitely don't feel that way about most brakes, I can't ride Sram G2s or Level 4 pistons at all, just hate the way they feel, and then brakes like the Codes, or Magura MT5s took getting used to, but I could use them. If I were to buy a set of the Formulas, I would also get a small stock of brake pads at the same time just in case I'm out traveling somewhere because they're not going to be in every shop, but I run into that problem with my Dominions anyways. 

2/1/2025 3:43pm

It’s the TechTech New Hope 4v. Totally different from the Hope Tech V4. You silly American.

2
Primoz
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2/3/2025 11:22am

For bleeding brakes, has anyone thought of doing it with a vacuum machine? Setting the vacuum low enough (for example 0,9 bar absolute pressure or something like that) and connecting both sides of the brake to the same reservoir (Y connection) and vacuuming the reservoir, theoretically you could pull out all the bubbles and with the reservoir they could easily be replaced by oil flowing in from either side.

Eae903
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2/3/2025 11:35am
Primoz wrote:
For bleeding brakes, has anyone thought of doing it with a vacuum machine? Setting the vacuum low enough (for example 0,9 bar absolute pressure or something...

For bleeding brakes, has anyone thought of doing it with a vacuum machine? Setting the vacuum low enough (for example 0,9 bar absolute pressure or something like that) and connecting both sides of the brake to the same reservoir (Y connection) and vacuuming the reservoir, theoretically you could pull out all the bubbles and with the reservoir they could easily be replaced by oil flowing in from either side.

My shop is getting a Vaccum fill machine to work on suspension with, specially cane Creek stuff, and if I can I'll see if I can get it to work with brakes, but I have a feeling it's not going to be worth the time and effort. 

HexonJuan
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USA
2/6/2025 2:07pm
Primoz wrote:
For bleeding brakes, has anyone thought of doing it with a vacuum machine? Setting the vacuum low enough (for example 0,9 bar absolute pressure or something...

For bleeding brakes, has anyone thought of doing it with a vacuum machine? Setting the vacuum low enough (for example 0,9 bar absolute pressure or something like that) and connecting both sides of the brake to the same reservoir (Y connection) and vacuuming the reservoir, theoretically you could pull out all the bubbles and with the reservoir they could easily be replaced by oil flowing in from either side.

Eae903 wrote:
My shop is getting a Vaccum fill machine to work on suspension with, specially cane Creek stuff, and if I can I'll see if I can...

My shop is getting a Vaccum fill machine to work on suspension with, specially cane Creek stuff, and if I can I'll see if I can get it to work with brakes, but I have a feeling it's not going to be worth the time and effort. 

Seems like the potential hassle of fully cleaning/purging the different fluids from it may not be ideal.

2
Evil96
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2/7/2025 11:54am

I finally made up my mind on what to replace my MT7 with, the feel and performance of these Tech 4 V4 is impressive, super light action, PLENTY of power while having a impressive amount of modulation, just wow.

With the braided hoses I got a very stiff brake, front and rear feel identical and the bite point is real sharp, not spongy at all.

That being said I decided to go with the TRP RS05 rotors, paired with the stock Race pads, bedding in and first couple mellow rides were nice and quiet, after that it’s squealing like crazy, every time I brake, no matter the intensity or if hot/cold, any tips?

I already tried ala Bee Kay to rub the pads under water and nothing changed

 

Forest-13
1
Simann
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Murfreesboro, TN, USA
2/8/2025 10:39am Edited Date/Time 2/8/2025 10:40am
Evil96 wrote:
I finally made up my mind on what to replace my MT7 with, the feel and performance of these Tech 4 V4 is impressive, super light...

I finally made up my mind on what to replace my MT7 with, the feel and performance of these Tech 4 V4 is impressive, super light action, PLENTY of power while having a impressive amount of modulation, just wow.

With the braided hoses I got a very stiff brake, front and rear feel identical and the bite point is real sharp, not spongy at all.

That being said I decided to go with the TRP RS05 rotors, paired with the stock Race pads, bedding in and first couple mellow rides were nice and quiet, after that it’s squealing like crazy, every time I brake, no matter the intensity or if hot/cold, any tips?

I already tried ala Bee Kay to rub the pads under water and nothing changed

 

Forest-13

I ran all the Hope pads over the course of a year on my T4 V4's, never had a squeal. But I was using the Hope rotor as well. The TRP rotor alloy may not be a good fit for the Hope pad compound. 

Also, I know you said you have a stiff bite point and no sponginess, but is it possible the pistons are not contacting the pad equally? 

Reason I bring this up is that I had to re center the pads probably once a month. The caliper was not walking on its mount, but it was that the Hope V4 caliper did not engage all of the pistons simultaneously. The banks of pistons would push the pads unequally against the rotor face and cause some weird engagement and pad wear. There are actually a few videos on YT that I discovered about this,

1
AndehM
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2/8/2025 11:12am

I think the big difference between the Canyon video and the latest official SRAM ones is the process for isolating the caliper (by rubber banding lever to bar), then islolating the lever (by closing the caliper bleed syringe & Bleeding Edge fitting).  There are a few other minor differences too like setting contact adjust fully in and reach fully out (both to open up the lever volume as much as possible).

1
ex-ballz
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Ouagadougou, EH
2/8/2025 11:18am
Evil96 wrote:
I finally made up my mind on what to replace my MT7 with, the feel and performance of these Tech 4 V4 is impressive, super light...

I finally made up my mind on what to replace my MT7 with, the feel and performance of these Tech 4 V4 is impressive, super light action, PLENTY of power while having a impressive amount of modulation, just wow.

With the braided hoses I got a very stiff brake, front and rear feel identical and the bite point is real sharp, not spongy at all.

That being said I decided to go with the TRP RS05 rotors, paired with the stock Race pads, bedding in and first couple mellow rides were nice and quiet, after that it’s squealing like crazy, every time I brake, no matter the intensity or if hot/cold, any tips?

I already tried ala Bee Kay to rub the pads under water and nothing changed

 

Forest-13

I alternate two wheelsets with the T4V4s and TRP R1 rotors are definitely noisier than Trickstuff Daechle HDs. 

1
Evil96
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Portogruaro, VE, IT
2/8/2025 11:30am
Simann wrote:
I ran all the Hope pads over the course of a year on my T4 V4's, never had a squeal. But I was using the Hope...

I ran all the Hope pads over the course of a year on my T4 V4's, never had a squeal. But I was using the Hope rotor as well. The TRP rotor alloy may not be a good fit for the Hope pad compound. 

Also, I know you said you have a stiff bite point and no sponginess, but is it possible the pistons are not contacting the pad equally? 

Reason I bring this up is that I had to re center the pads probably once a month. The caliper was not walking on its mount, but it was that the Hope V4 caliper did not engage all of the pistons simultaneously. The banks of pistons would push the pads unequally against the rotor face and cause some weird engagement and pad wear. There are actually a few videos on YT that I discovered about this,

took me a minute but the pistons and pads are all perfectly centered, same is the rotor

Evil96
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2/8/2025 11:32am
ex-ballz wrote:

I alternate two wheelsets with the T4V4s and TRP R1 rotors are definitely noisier than Trickstuff Daechle HDs. 

how do the v4 behave with 2mm rotors? reason i went with these other than look is thickness and stiffness, given the v4 caliper is meant to use the 3.3mm rotors, and the floating are just 1.8 ( which i find ridiculous ) i went for something in between, feel is amazing but yeah the noise is the issue, the r1 were noisy on my mt7 but lacked bite badly, these are good rotors so i think it's pad compound or something else

2/8/2025 12:03pm

It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same sound lol.

1
ex-ballz
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2/8/2025 1:17pm Edited Date/Time 2/8/2025 1:17pm
ex-ballz wrote:

I alternate two wheelsets with the T4V4s and TRP R1 rotors are definitely noisier than Trickstuff Daechle HDs. 

Evil96 wrote:
how do the v4 behave with 2mm rotors? reason i went with these other than look is thickness and stiffness, given the v4 caliper is meant...

how do the v4 behave with 2mm rotors? reason i went with these other than look is thickness and stiffness, given the v4 caliper is meant to use the 3.3mm rotors, and the floating are just 1.8 ( which i find ridiculous ) i went for something in between, feel is amazing but yeah the noise is the issue, the r1 were noisy on my mt7 but lacked bite badly, these are good rotors so i think it's pad compound or something else

The work just fine with the 2.05mm rotors, but with the 2.3mm ones, they are more bitey. It's harder to balance the pistons with the thicker rotor, though.

TSchafer
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Denver, CO, USA
2/9/2025 8:15am
It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same...

It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same sound lol.

Totally! I asked pages back about reducing Hope noise, and nothing helped. They work amazingly though so just accepting the squeal.

1
Evil96
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Portogruaro, VE, IT
2/9/2025 10:16am
It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same...

It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same sound lol.

TSchafer wrote:

Totally! I asked pages back about reducing Hope noise, and nothing helped. They work amazingly though so just accepting the squeal.

i won't give up ahah

 

1
TimBud
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GB
2/9/2025 11:31am

Hope always have that high pitched squeal.


Its not bad like a honking wet Sram brake, but it is almost constant.


I run the Sram 2mm rotors on my setup and all is good so far (race pads fitted)

1
2/10/2025 5:05am

I've had T4 and there were a bit noisy with the hope green pads. Using trickstuff or Galfer green and it was dead silent, no matter the weather. Sinter green are also very very quiet pads.

3
Evil96
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2/10/2025 9:50am
petoulachi wrote:
I've had T4 and there were a bit noisy with the hope green pads. Using trickstuff or Galfer green and it was dead silent, no matter...

I've had T4 and there were a bit noisy with the hope green pads. Using trickstuff or Galfer green and it was dead silent, no matter the weather. Sinter green are also very very quiet pads.

Any preference between these? I only tried the trickstuff properly and the sinter green were pretty good, similar to the Trickstuff

Never tried the green galfer

Primoz
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SI
2/10/2025 10:30am
AndehM wrote:
I think the big difference between the Canyon video and the latest official SRAM ones is the process for isolating the caliper (by rubber banding lever...

I think the big difference between the Canyon video and the latest official SRAM ones is the process for isolating the caliper (by rubber banding lever to bar), then islolating the lever (by closing the caliper bleed syringe & Bleeding Edge fitting).  There are a few other minor differences too like setting contact adjust fully in and reach fully out (both to open up the lever volume as much as possible).

Yeah, this was all part of the older style guide to bleed Sram brakes... Weird that they simplified it this much.

sprungmass
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Calgary, AB, CA
2/10/2025 10:52am

Since on we are on the topic of brake pads, does anyone have any recommendations for Hayes Dominion A4? My use case is exclusively snow riding in cold temps. I tried their OEM organic pads but they barely lasted a month. Now I am on the OEM metallic pads and they are unbearably loud as soon as the smallest amount of snow touches the rotor. I guess we can compare this to riding in the wet.

I used to run SRAM Code RSC with Trickstuff Power pads and that was a great quiet combo. Unfortunately Trickstuff does not make pads for Dominions. Is the Galfer Pro green a bit similar to TS? My other choice would be the Sinter brand in the same green compound. Thoughts?

2/10/2025 1:20pm
sprungmass wrote:
Since on we are on the topic of brake pads, does anyone have any recommendations for Hayes Dominion A4? My use case is exclusively snow riding...

Since on we are on the topic of brake pads, does anyone have any recommendations for Hayes Dominion A4? My use case is exclusively snow riding in cold temps. I tried their OEM organic pads but they barely lasted a month. Now I am on the OEM metallic pads and they are unbearably loud as soon as the smallest amount of snow touches the rotor. I guess we can compare this to riding in the wet.

I used to run SRAM Code RSC with Trickstuff Power pads and that was a great quiet combo. Unfortunately Trickstuff does not make pads for Dominions. Is the Galfer Pro green a bit similar to TS? My other choice would be the Sinter brand in the same green compound. Thoughts?

I've used both the galfer green pads and TS power pads (admittedly on different brakes to yours, Shimano and Cura 4s). I found them Galfers to be just as good as the TS pads and easier to get hold of. Would be my go to choice now.

1
2/10/2025 1:30pm
It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same...

It's funny how some hope users say never had a noise etc But yet from hope and all the pro's who use them have the same sound lol.

TSchafer wrote:

Totally! I asked pages back about reducing Hope noise, and nothing helped. They work amazingly though so just accepting the squeal.

Evil96 wrote:

i won't give up ahah

 

I've had good luck with Hope Sintered pads mated to Freeza rotors. Very little, if any noise in the wet after a minute going downhill 

1
Slavid666
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Location
Santa Rosa, CA, USA
2/10/2025 7:45pm
sprungmass wrote:
Since on we are on the topic of brake pads, does anyone have any recommendations for Hayes Dominion A4? My use case is exclusively snow riding...

Since on we are on the topic of brake pads, does anyone have any recommendations for Hayes Dominion A4? My use case is exclusively snow riding in cold temps. I tried their OEM organic pads but they barely lasted a month. Now I am on the OEM metallic pads and they are unbearably loud as soon as the smallest amount of snow touches the rotor. I guess we can compare this to riding in the wet.

I used to run SRAM Code RSC with Trickstuff Power pads and that was a great quiet combo. Unfortunately Trickstuff does not make pads for Dominions. Is the Galfer Pro green a bit similar to TS? My other choice would be the Sinter brand in the same green compound. Thoughts?

Sinter Greens. Haven’t run TS’s but out of MTX, Red’s, Golds, both Hayes compounds and Galfer greens, the sinters are the best I’ve used. Run them on A4’s and Kaha’s with the new SE05 TRP rotors on one bike and Galfer Waves on another. Dead silent and more power regardless of how wet it is. Only have a few hundred miles so far but they seem to be wearing well. The stock Kaha pads made the most bizarre warbling noise when you got on the brakes hard. Not quite OG sram turkey call but similar. Drove me nuts.

3
2/11/2025 12:20am Edited Date/Time 2/11/2025 12:21am
petoulachi wrote:
I've had T4 and there were a bit noisy with the hope green pads. Using trickstuff or Galfer green and it was dead silent, no matter...

I've had T4 and there were a bit noisy with the hope green pads. Using trickstuff or Galfer green and it was dead silent, no matter the weather. Sinter green are also very very quiet pads.

Evil96 wrote:

Any preference between these? I only tried the trickstuff properly and the sinter green were pretty good, similar to the Trickstuff

Never tried the green galfer

Well, there are quite similar but :

-Galfer are the noisier of the 3. It's subtle but there do make a bit of noise. Trickstuff are second, the Sinter are the most silent I've tried. But we can say that the 3 are silent, it's just nutpicking here

-The galfer fade faster than Trickstuff. Can't say for the Sinter has I've don't run them for long enough to know

 

So the galfer are a bit behind, BUT there usually are cheaper. Can't really go wrong with any of these!

1

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