Nerding out on Brakes shall we? Not another tech deraliment

Evil96
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Portogruaro, VE IT
2/11/2025 12:39am
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

petoulachi wrote:
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...

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!

that's interesting, i guess it also depends on what brakes you used them?

on MT7 the Trickstuff power were impossible to fade for me, and pretty quiet especially at speed, the sinter green i didn't keep for long but i found a bit more bitey and a touch more noisy, Galfer i only tried the purple and found them horrible on maguras, black caliper every run, trickstuff kept everything WAY cleaner

2/11/2025 12:45am

It was on T4V4 / Intend Trinity, same feeling for me on both brakes.

1
sprungmass
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Calgary, AB CA
2/11/2025 6:49am
Slavid666 wrote:
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...

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.

Thanks, I will give these Sinter guys a shot. I was always intrigued after reading the Enduro Mag brake shootout and how powerful they are. Also the fact couple of you here are saying they are super silent so these should be the ticket to a peaceful descent. 

@Pedal Bob There "performance organics" from likes of Trickstuff and Galfer are something special and can't be compared to the organic offerings from SRAM/Shimano. I have faded SRAM metallic pads on our long mountain descents while had zero issues with Trickstuff pads. No change in feel, power and last a long time.

2
Teknik
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FI
2/11/2025 7:33am

Nobody seems to run with Shimano OEM metallic pads or atleast  writing any comments to forums. 

Are the all other brands so much better?

2/11/2025 7:55am
Teknik wrote:

Nobody seems to run with Shimano OEM metallic pads or atleast  writing any comments to forums. 

Are the all other brands so much better?

I started using Galfer green pads instead of Shimano because they were significantly cheaper, quieter and didn't feel like I gave up any performance. Galfer's aren't as cheap as they used to be, but still my go to (when using Shimano)

2/11/2025 10:46am
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

I'm currently run v4 with sram centerline rotors (1.8 ) while awaiting shipment of thicker rotors, works just fine, U will need to file down sram brake mount adapter to fit caliper on 200mm rotor tho (code replacement on the bike)

Pedal Bob
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H NO
2/11/2025 11:44am Edited Date/Time 2/11/2025 11:47am
Slavid666 wrote:
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...

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.

sprungmass wrote:
Thanks, I will give these Sinter guys a shot. I was always intrigued after reading the Enduro Mag brake shootout and how powerful they are. Also...

Thanks, I will give these Sinter guys a shot. I was always intrigued after reading the Enduro Mag brake shootout and how powerful they are. Also the fact couple of you here are saying they are super silent so these should be the ticket to a peaceful descent. 

@Pedal Bob There "performance organics" from likes of Trickstuff and Galfer are something special and can't be compared to the organic offerings from SRAM/Shimano. I have faded SRAM metallic pads on our long mountain descents while had zero issues with Trickstuff pads. No change in feel, power and last a long time.

I'm going for Dominion A4's this coming season, and as they come delivered with both their organic and metallic pads, I feel I can just drop an order on those Sinter greens myself as well. If they're good, they're good, and if not I can at least try the stock metallic pads(little faith in their stock organic)

1
HexonJuan
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WI US
2/11/2025 12:30pm

Hel no. The design language is so diff between the caliper and the MC. The caliper looks good, the MC looks like a prototype OG Shimanos.

 

1
FaahkEet
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Falls Church, VA US
2/11/2025 12:38pm
Pedal Bob wrote:
I'm going for Dominion A4's this coming season, and as they come delivered with both their organic and metallic pads, I feel I can just drop...

I'm going for Dominion A4's this coming season, and as they come delivered with both their organic and metallic pads, I feel I can just drop an order on those Sinter greens myself as well. If they're good, they're good, and if not I can at least try the stock metallic pads(little faith in their stock organic)

I've been using the Gold pads from Hardheaded Ram for Dominion A4 calipers the past year and a 1/2, and they've worked really well. Especially for the price, assuming in the US.

I'm thinking about trying the Blue and maybe Green as well. I'll have to do deep clean of the rotors though for that. 

Slavid666
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Santa Rosa, CA US
2/11/2025 5:58pm
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?

Slavid666 wrote:
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...

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.

Pedal Bob wrote:
I read on their page that they only make organic pads. I also see Galfer only offer organic, but for some reason have sinter pads aimed...

I read on their page that they only make organic pads. I also see Galfer only offer organic, but for some reason have sinter pads aimed at trial. 

My only experience with organic in the past is they bite better initially, but fade very fast. It feels like you are comparing organic pads to  (mostly)organic pads, which make me wonder if there are certain brands that offer certain organic mixes that can run with metallic. I see the two of you are conscious about noise, but if we put that to the side and only focus on performance, which will have the stronger bite and a bite that will last?

Being on the larger end of the human spectrum, 6’3” and 210lbs, I would agree that normal organics tend to fade hard when compared to metallics, especially when they get hot. Have found that the Sinters and Galfers don’t behave that way at all. It’s been a minute since I’ve run the Galfers but I don’t remember them ever feeling that way. The sinters just grab. Have had a few runs that were nonstop down 4k feet of elevation and they were good top to bottom, those were at the end of the season last year when we were still seeing ambient temps over 95f. 

The ceramic based MTX’s seemed to need a lot of heat in them to get good initial bite out them. I liked the reds over the golds.

In the US the Sinters ship from unior USA and are $35 a pair if I remember correctly. Pretty cheap all things considered. 

Was thinking or grabbing TS’s for the kahas after the sinters wear out, but I like keeping the same pads on both bikes so I toss the carbon wheels on the enduro bike for days when theres no lifts or shuttles for the rides, that bike goes through pads much faster than the trail bike.

3
Pedal Bob
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2/11/2025 11:22pm
Slavid666 wrote:
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...

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.

Pedal Bob wrote:
I read on their page that they only make organic pads. I also see Galfer only offer organic, but for some reason have sinter pads aimed...

I read on their page that they only make organic pads. I also see Galfer only offer organic, but for some reason have sinter pads aimed at trial. 

My only experience with organic in the past is they bite better initially, but fade very fast. It feels like you are comparing organic pads to  (mostly)organic pads, which make me wonder if there are certain brands that offer certain organic mixes that can run with metallic. I see the two of you are conscious about noise, but if we put that to the side and only focus on performance, which will have the stronger bite and a bite that will last?

Slavid666 wrote:
Being on the larger end of the human spectrum, 6’3” and 210lbs, I would agree that normal organics tend to fade hard when compared to metallics...

Being on the larger end of the human spectrum, 6’3” and 210lbs, I would agree that normal organics tend to fade hard when compared to metallics, especially when they get hot. Have found that the Sinters and Galfers don’t behave that way at all. It’s been a minute since I’ve run the Galfers but I don’t remember them ever feeling that way. The sinters just grab. Have had a few runs that were nonstop down 4k feet of elevation and they were good top to bottom, those were at the end of the season last year when we were still seeing ambient temps over 95f. 

The ceramic based MTX’s seemed to need a lot of heat in them to get good initial bite out them. I liked the reds over the golds.

In the US the Sinters ship from unior USA and are $35 a pair if I remember correctly. Pretty cheap all things considered. 

Was thinking or grabbing TS’s for the kahas after the sinters wear out, but I like keeping the same pads on both bikes so I toss the carbon wheels on the enduro bike for days when theres no lifts or shuttles for the rides, that bike goes through pads much faster than the trail bike.

Good to hear that it is possible to make pads in another way, and also gain different positive properties.

I'm willing to test the Sinter greens this coming season, but as I'm also going for complete new brakes also with rotors, I'm just curious what others do when it comes to trying different pads on the same rotors. Years ago I heard you should not use organic pads on same rotors as metallic and vice verca, but does that still come true today?

It's a bit over the top and get two sets of rotors and swap back and forth, so what do others do because if I start running Sinter greens on brand new rotors, what do I do if I want to try to stock metallic pads that come with the Dominion A4's?

It would be good to be able to test more pads myself and get something to compare to.

FaahkEet
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2/12/2025 5:24am
Pedal Bob wrote:
Good to hear that it is possible to make pads in another way, and also gain different positive properties.I'm willing to test the Sinter greens this...

Good to hear that it is possible to make pads in another way, and also gain different positive properties.

I'm willing to test the Sinter greens this coming season, but as I'm also going for complete new brakes also with rotors, I'm just curious what others do when it comes to trying different pads on the same rotors. Years ago I heard you should not use organic pads on same rotors as metallic and vice verca, but does that still come true today?

It's a bit over the top and get two sets of rotors and swap back and forth, so what do others do because if I start running Sinter greens on brand new rotors, what do I do if I want to try to stock metallic pads that come with the Dominion A4's?

It would be good to be able to test more pads myself and get something to compare to.

As far as I know you only need to be conscious of pad compounds when rotors specify pad compounds. Otherwise just a good clean when going between pad compounds is all that's needed. Maybe a light sanding after a round of brake rotor cleaner

2
Digit Bikes
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2/13/2025 12:03pm Edited Date/Time 2/14/2025 8:27am
For longer levers you could try BL-MT410. At Sea Otter, Evan of Contra displayed his bike at my booth and we had a little Shigura convention...

For longer levers you could try BL-MT410.

At Sea Otter, Evan of Contra displayed his bike at my booth and we had a little Shigura convention, we had 3 variants. All used Magura 4-pot calipers. Ring used non-servowave XTR BL-M9100; Datum used Servowave XTR BL-M9120; Contra used long-levered non-Servowave BL-MT410.

We both said that our primary motivations were ergonomics/reliability. I like the reliabilty of the Magura calipers (I'd prefer if the pads retracted futher), and I like that the Shimano levers have the hose pointing in the correct direction and have good shifter integration (I've never gotten along with the ergonomics resulting from 2 bolt clamp shifter integration).

Regarding Servowave: in use the biggest things I notice is that the reach adjust on BL-M9100 is fiddly, and the carbon lever is a little bit thinner, so the BL-M9120 lever is a wee bit more comfortable. The Servowave lever does have a shorter stroke than the non-Servowave lever. Maybe I'll assemble a bike with M9100 on one side and M9120 on the other to get a better feel for the difference that Servowave makes.

Regarding power: Perhaps more than enough braking power is enough, and much more than enough braking power is also enough. Just enough braking power is only enough until something unexpected happens so it's best to have a little bit more than 100% of what's needed.

Regarding numbers: Reducing performance to a single number, be it brake leverage, antisquat, weight, other, can distract from choosing a better, complete solution. 

An update to my Shigura experiences:

I've decided I prefer the Servowave levers over the non-Servowave levers. Not because of the Servowave itself, but because they have the free-stroke adjuster.

Interestingly I don't actually use the freestroke adjuster, on M9120  it comes already adjusted in the close to the handlebar position, on M9100 unfortunately the resting position of the lever is always too far away (for my tastes).

3
HexonJuan
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2/13/2025 1:08pm
Pedal Bob wrote:
Good to hear that it is possible to make pads in another way, and also gain different positive properties.I'm willing to test the Sinter greens this...

Good to hear that it is possible to make pads in another way, and also gain different positive properties.

I'm willing to test the Sinter greens this coming season, but as I'm also going for complete new brakes also with rotors, I'm just curious what others do when it comes to trying different pads on the same rotors. Years ago I heard you should not use organic pads on same rotors as metallic and vice verca, but does that still come true today?

It's a bit over the top and get two sets of rotors and swap back and forth, so what do others do because if I start running Sinter greens on brand new rotors, what do I do if I want to try to stock metallic pads that come with the Dominion A4's?

It would be good to be able to test more pads myself and get something to compare to.

FaahkEet wrote:
As far as I know you only need to be conscious of pad compounds when rotors specify pad compounds. Otherwise just a good clean when going...

As far as I know you only need to be conscious of pad compounds when rotors specify pad compounds. Otherwise just a good clean when going between pad compounds is all that's needed. Maybe a light sanding after a round of brake rotor cleaner

I can't say I know of a single company that says that's ok. Pad material gets embedded into the rotor surface, so even with a light sanding you won't get all of it out. That embedded material is what creates most of the friction between the pads and rotors. The difference between the pad compounds will affect peak performance. Will it be to betterment or detriment is an unknown. Even fuller disclosure, I am guilty as allllll get out of doing this, but it's always been between like compounds, in my case sintered pads for sintered pads from diff manufacturers. I have not tried cross breeding (Ha!) with semi met/organics or with ceramics, so caveat emptor. I'm giving ceramics a go on my roadie and I am swapping rotors when I do. First time trying em out and I want to have as close to a best use scenario to give em a proper chance. Hoping to remedy some of the sintered screams of freezing cold pads and rotors (New band name, Sintered Screams).  Anyway, if the mix and match doesn't give the results you were hoping for, don't necessarily hold it all against the compound/manufacturer. 

FaahkEet
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2/13/2025 2:13pm Edited Date/Time 2/13/2025 2:14pm
HexonJuan wrote:
I can't say I know of a single company that says that's ok. Pad material gets embedded into the rotor surface, so even with a light...

I can't say I know of a single company that says that's ok. Pad material gets embedded into the rotor surface, so even with a light sanding you won't get all of it out. That embedded material is what creates most of the friction between the pads and rotors. The difference between the pad compounds will affect peak performance. Will it be to betterment or detriment is an unknown. Even fuller disclosure, I am guilty as allllll get out of doing this, but it's always been between like compounds, in my case sintered pads for sintered pads from diff manufacturers. I have not tried cross breeding (Ha!) with semi met/organics or with ceramics, so caveat emptor. I'm giving ceramics a go on my roadie and I am swapping rotors when I do. First time trying em out and I want to have as close to a best use scenario to give em a proper chance. Hoping to remedy some of the sintered screams of freezing cold pads and rotors (New band name, Sintered Screams).  Anyway, if the mix and match doesn't give the results you were hoping for, don't necessarily hold it all against the compound/manufacturer. 

I mean, yeah the brake companies will say use new rotors but they also have a financial interest for new rotors to be purchased. (Adjusts tin foil hat)

Going from resin to sintered, most pad material deposited will most likely be abraded out. Maybe going sintered to resin a resurface or new rotors would be called for.

I've gone from sintered to ceramic and back with no noticeable degradation in braking performance. In the moto world I've heard of taking abrasive pads to rotors, resurface if there's a noticeable problem and there's enough rotor left. 

Probably need a side by side test and maybe an electron microscope to see the real world implications. But I ain't got the funds for that. 

I will be receiving new pads next week, ceramic and some other mix, and I have sintered currentl  mounted, so maybe I'll try an unscientific beer fueled experiment that will be null and void, and probably injurious but science!

 

3
sprungmass
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Calgary, AB CA
2/13/2025 2:14pm Edited Date/Time 2/13/2025 2:15pm

Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands. I even do this when changing pads to fresh ones. Never let me down.

Screenshot 2025-02-13 150822

 

image 192
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2/13/2025 4:20pm
sprungmass wrote:
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands...

Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands. I even do this when changing pads to fresh ones. Never let me down.

Screenshot 2025-02-13 150822

 

image 192

Fkn yes! This is the sort of ingenuity that I come here for. 

3
DServy
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Jackson, WY US
2/13/2025 4:24pm
sprungmass wrote:
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands...

Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands. I even do this when changing pads to fresh ones. Never let me down.

Screenshot 2025-02-13 150822

 

image 192
Johnboy wrote:

Fkn yes! This is the sort of ingenuity that I come here for. 

looks like i'm buying a sander....

5
Evil96
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Portogruaro, VE IT
2/13/2025 11:29pm

not sure why i'm not a fan of sand paper and rotors, i feel they would become uneven and do more harm than good

 

2/14/2025 3:34am

Well I have access to a high accuracy surface grinder at work, I wonder how I can get it to hold brake rotors.

2
HexonJuan
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2/14/2025 6:10am
sprungmass wrote:
Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands...

Orbital sander + 120 grit pad 20-30 seconds on each side x2 using medium pressure. This is how I prep my rotors when changing pad compounds/brands. I even do this when changing pads to fresh ones. Never let me down.

Screenshot 2025-02-13 150822

 

image 192

Your commitment to the cause is notable and commendable!

2
ITBVolks
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CANTERBURY, CT US
2/14/2025 6:17am

Well I have access to a high accuracy surface grinder at work, I wonder how I can get it to hold brake rotors.

Magnetic base.

3
HexonJuan
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2/14/2025 6:32am Edited Date/Time 2/14/2025 6:34am

Story time. Ages ago, a good customer at the shop I worked at picked up some fancy aluminum Italian road frame and at the same time a brand new Phil Wood bottom bracket to go with it. He installs it and torques to spec (he was a highly competent home mech and used us when the WTF quotient got outta hand) and goes to tweak the chainline some and lo n behold, bottom bracket is frozen solid. Keep in mind, this is brand new, hasn't had the wheels installed yet much less been on a ride. We're contemplating the hows and decided to call Phil before proceeding with any plans from C on up the alphabet. Good thing we did. The cups and the frame were made from the same grade aluminum and had the same heat treat. This in turn meant the thread surfaces had near identical surface finish/topography, so when the BB was tightened to torque, those high and low surfaces interlocked to each other fast, creating a mechanical seizure between the mating parts. Keep in mind those surfaces would need to be seen under a microscope, you wouldn't see any difference, and the threads were greased properly. So, turns out ours and our customer's ignorance of this material property was at fault, and Phil has cups made from a different alloy strictly for this reason. Thankfully we didn't sell em the wares or that would've been an expensive error. 

So what's that got to do with brakes? Simple. Different compounds will have a different 'grit' if you will, be it size, composition, or both. Doubt my claim? Take different grit sandpapers and rub them against each other, grit to grit. Note which ones slide easier and which ones lock up. The same grit sandpaper will damn near be impossible to rub against each other under pressure. The closer you get to the same grit, the more /easier the grit will interlock with each other, their topography matches.  If you want the most consistent braking possible, replace with like or be prepared to take an orbital sander to a rotor if you don't want to replace it. Thank you for attending my Ted Talk. 

9
HexonJuan
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2/14/2025 6:37am Edited Date/Time 2/14/2025 6:39am
Evil96 wrote:

not sure why i'm not a fan of sand paper and rotors, i feel they would become uneven and do more harm than good

 

That would require a helluvan aggressive abrasive and muscle. I'm not a fan of sandpaper as I don't know the composition of the adhesive and abrasive and don't want to potentially cause a contamination issue on the rotor surface resulting in poor braking characteristics. I think about how much I clean the metals I TIG when after cutting/grinding and apply the same reasoning to my rotors. Maybe I think too hard on these bits, def a possibility.

1
ballz
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2/14/2025 7:32am

How about some good ole (glass) lapping plate and fine lapping compound? Still too much risk of having the compound getting embedded in the rotors?

2/14/2025 7:32am
Evil96 wrote:

not sure why i'm not a fan of sand paper and rotors, i feel they would become uneven and do more harm than good

 

Rotors are hardened steel -- you're not removing a meaningful amount of material.

2
sprungmass
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2/14/2025 8:30am
ballz wrote:

How about some good ole (glass) lapping plate and fine lapping compound? Still too much risk of having the compound getting embedded in the rotors?

That would be overkill and not necessary. The goal is to scuff up the rotor surface so the new pads can deposit themselves quickly, evenly and efficiently. You really don't need fine sanding compounds for this. Nuke it with some 99% ISO or brake clean for added peace of mind. From Hexon's TED talk, we can gather that we want to match the roughness of the pad and rotor for maximum interlocking. Lapping happens naturally when you ride the bike.

2
2/14/2025 4:07pm
ballz wrote:

How about some good ole (glass) lapping plate and fine lapping compound? Still too much risk of having the compound getting embedded in the rotors?

sprungmass wrote:
That would be overkill and not necessary. The goal is to scuff up the rotor surface so the new pads can deposit themselves quickly, evenly and...

That would be overkill and not necessary. The goal is to scuff up the rotor surface so the new pads can deposit themselves quickly, evenly and efficiently. You really don't need fine sanding compounds for this. Nuke it with some 99% ISO or brake clean for added peace of mind. From Hexon's TED talk, we can gather that we want to match the roughness of the pad and rotor for maximum interlocking. Lapping happens naturally when you ride the bike.

Agree that people misinterpret "sanding the rotors" as it's commonly practiced (or at least as I do it).  I think of it like taking a brillo pad to a pot - very aggressive cleaning.  I'm not trying to really "sand" the rotor.  Just take off the most microscopic top layer of pad material and scuff it up enough to remate with new pads. 

3
2/15/2025 4:54am

I never prep my rotors. I just run cheap 2,50 chinese resin pads and they all bite the same. To bed them in more quickly just use a few drops of water. 

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Primoz
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2/15/2025 7:54am
HexonJuan wrote:
Story time. Ages ago, a good customer at the shop I worked at picked up some fancy aluminum Italian road frame and at the same time...

Story time. Ages ago, a good customer at the shop I worked at picked up some fancy aluminum Italian road frame and at the same time a brand new Phil Wood bottom bracket to go with it. He installs it and torques to spec (he was a highly competent home mech and used us when the WTF quotient got outta hand) and goes to tweak the chainline some and lo n behold, bottom bracket is frozen solid. Keep in mind, this is brand new, hasn't had the wheels installed yet much less been on a ride. We're contemplating the hows and decided to call Phil before proceeding with any plans from C on up the alphabet. Good thing we did. The cups and the frame were made from the same grade aluminum and had the same heat treat. This in turn meant the thread surfaces had near identical surface finish/topography, so when the BB was tightened to torque, those high and low surfaces interlocked to each other fast, creating a mechanical seizure between the mating parts. Keep in mind those surfaces would need to be seen under a microscope, you wouldn't see any difference, and the threads were greased properly. So, turns out ours and our customer's ignorance of this material property was at fault, and Phil has cups made from a different alloy strictly for this reason. Thankfully we didn't sell em the wares or that would've been an expensive error. 

So what's that got to do with brakes? Simple. Different compounds will have a different 'grit' if you will, be it size, composition, or both. Doubt my claim? Take different grit sandpapers and rub them against each other, grit to grit. Note which ones slide easier and which ones lock up. The same grit sandpaper will damn near be impossible to rub against each other under pressure. The closer you get to the same grit, the more /easier the grit will interlock with each other, their topography matches.  If you want the most consistent braking possible, replace with like or be prepared to take an orbital sander to a rotor if you don't want to replace it. Thank you for attending my Ted Talk. 

What you're describing is galling. A situation where a like-for-like metal will basically weld itself in the threads. Some metals are more susceptible to this than others. You can see the effect here:
https://www.youtube.com/watch?v=R54spcBn-Sk

Or here: https://www.youtube.com/watch?v=mHAhfX7iRjs

Or here: https://www.youtube.com/watch?v=jlDUqf-1XsM

The point is, galling is not relevant to brakes. Unless you're trying to use brake pads that are a billet of the same stainless steel that's used for the rotors. Then maybe.

 

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