Nerding out on Brakes shall we? Not another tech deraliment

Primoz
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5/13/2025 7:15am

How do those aliexpress pads compare to pads that I will actually buy and use in the brake at some point? 

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4
bcurrancy
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5/13/2025 7:40am

I find brake tests with a controlled pad and rotor combo are far more valuable… it allows you to standardize some variables and compare the actual brakes performance. Brakes sets are hardly ever shipped with rotors and the brakes will far outlive the stock pads so you certainly aren’t stuck with them. I’ve run codes, trp, and dominions over the last several years most often with galfer rotors and have always moved to galfer or mtx pads if I even bothered to wear through the stock pads. Sure a test with both stock and controlled pads/ rotors would be ideal but if we can only have one I’m taking the control. 

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k2fx
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5/13/2025 11:19am
I've never used them myself but from what I've heard from other people the crosshair alignment on the Hayes sounds great on paper, but not quite...

I've never used them myself but from what I've heard from other people the crosshair alignment on the Hayes sounds great on paper, but not quite so useful in practise.

AgrAde wrote:
It's possible to use them wrong. If you follow the procedure that makes the most of them they're great, quite an improvement over the standard process...

It's possible to use them wrong. If you follow the procedure that makes the most of them they're great, quite an improvement over the standard process. If you don't, and take the same kind of approach you would with a brake that doesn't have them then they kinda just get in the way.

- Back out crosshair screws
- Push on caliper to move it inboard so outer pad is fully in contact with rotor
- Tighten down caliper bolts until you just can't move the caliper by hand (not until play is gone, i mean until you are unable to adjust it by hand at all)
- Tighten each crosshair screw until it hits the caliper bolt and starts to move the caliper outboard
- Edge the caliper out slowly, alternating the screws. You get the feel for it. Once you do, it's easy to do in three adjustments: one crosshair screw, then the other, then back to the first for the final adjustment
- Nip up rear caliper bolt then front caliper bolt.

If you try to use them with the bolts loose, they suck. Any movement at all in the caliper they suck. Don't try to loosen one bolt and then adjust it back the other way by loosening the crosshair screw while pushing on it with your thumb then retightening once it's in the right spot, it sucks. If you adjust while there's no tension on the bolt, everything hasn't squished down nicely yet so when you do tighten it down it moves the caliper slightly. If you do go too far outboard with your adjustment then back the screw out, push the caliper back, tighten the caliper back down, and then start again. But it's so easy to not overshoot the adjustment that you'll never do it once you're used to it.

Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter surface? I did and I swore that was causing issues with getting them aligned in the first place, eventually I gently hit the area w/ sandpaper and started ignoring the crosshair system.

AndehM
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5/13/2025 11:23am
I've never used them myself but from what I've heard from other people the crosshair alignment on the Hayes sounds great on paper, but not quite...

I've never used them myself but from what I've heard from other people the crosshair alignment on the Hayes sounds great on paper, but not quite so useful in practise.

AgrAde wrote:
It's possible to use them wrong. If you follow the procedure that makes the most of them they're great, quite an improvement over the standard process...

It's possible to use them wrong. If you follow the procedure that makes the most of them they're great, quite an improvement over the standard process. If you don't, and take the same kind of approach you would with a brake that doesn't have them then they kinda just get in the way.

- Back out crosshair screws
- Push on caliper to move it inboard so outer pad is fully in contact with rotor
- Tighten down caliper bolts until you just can't move the caliper by hand (not until play is gone, i mean until you are unable to adjust it by hand at all)
- Tighten each crosshair screw until it hits the caliper bolt and starts to move the caliper outboard
- Edge the caliper out slowly, alternating the screws. You get the feel for it. Once you do, it's easy to do in three adjustments: one crosshair screw, then the other, then back to the first for the final adjustment
- Nip up rear caliper bolt then front caliper bolt.

If you try to use them with the bolts loose, they suck. Any movement at all in the caliper they suck. Don't try to loosen one bolt and then adjust it back the other way by loosening the crosshair screw while pushing on it with your thumb then retightening once it's in the right spot, it sucks. If you adjust while there's no tension on the bolt, everything hasn't squished down nicely yet so when you do tighten it down it moves the caliper slightly. If you do go too far outboard with your adjustment then back the screw out, push the caliper back, tighten the caliper back down, and then start again. But it's so easy to not overshoot the adjustment that you'll never do it once you're used to it.

k2fx wrote:
Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter...

Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter surface? I did and I swore that was causing issues with getting them aligned in the first place, eventually I gently hit the area w/ sandpaper and started ignoring the crosshair system.

When I had a couple pairs of Dominions, I had the same thing happen on both.  (The top of the mounting surface got scoured by the bolt washer and led to the bolt loading up the top unevenly, or trying to push back into the lowest wear groove.)  Also the grub screw wore down the threads of the mount bolts.

AgrAde
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5/13/2025 1:08pm Edited Date/Time 5/13/2025 1:13pm
k2fx wrote:
Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter...

Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter surface? I did and I swore that was causing issues with getting them aligned in the first place, eventually I gently hit the area w/ sandpaper and started ignoring the crosshair system.

They're just tight enough to not move by hand, which isn't really any meaningful tension on the bolt, only really enough to squish the compressible stuff and hold everything square... Im sure I could make it move if I reefed on it. Haven't seen any wear. I guess it depends how often you realign them? I'm with the other guy a few posts back, align rotor to caliper and any pad misalignment is a piston problem.

 

I'll keep an eye on that though, thanks. 

1
yeahboiwahoo
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5/14/2025 3:03am

I did some freestroke measurements out of interest as it came up earlier on this page, I found across my two sets of code rsc how I have them adjusted I'm looking at about 20mm measured in the middle of the finger spot. I had a measure of 3 different shimano 2 pots (m785 xt x 4 and slx x2) and they were all around 22 to 24mm. What I found interesting was that all of the brakes I had engaged at basically the same point from the bar even with them all done by feel rather than a deliberate attempt. 

Anyone else got any data?

 

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AgrAde
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5/14/2025 3:22am Edited Date/Time 5/14/2025 3:30am

Wait I thought it was a well known and reliably documented characteristic that Dominions have extreme amounts of free stroke compared to Code RSCs. Are you telling me that that's not correct, and that they appear to have less?

1
k2fx
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5/14/2025 9:52am
k2fx wrote:
Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter...

Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter surface? I did and I swore that was causing issues with getting them aligned in the first place, eventually I gently hit the area w/ sandpaper and started ignoring the crosshair system.

AgrAde wrote:
They're just tight enough to not move by hand, which isn't really any meaningful tension on the bolt, only really enough to squish the compressible stuff...

They're just tight enough to not move by hand, which isn't really any meaningful tension on the bolt, only really enough to squish the compressible stuff and hold everything square... Im sure I could make it move if I reefed on it. Haven't seen any wear. I guess it depends how often you realign them? I'm with the other guy a few posts back, align rotor to caliper and any pad misalignment is a piston problem.

 

I'll keep an eye on that though, thanks. 

Yeah I may or may not have tried to align my way out of a bent rotor problem more than a couple times 😅

Definitely keep an eye on it and don't tighten your bolts too much before using em. I'm glad they're working for you, it was initially a decent part of the reason I was psyched to buy em (after that I just didn't care because they feel amazing and work great).

Eae903
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5/14/2025 3:04pm
AgrAde wrote:
Wait I thought it was a well known and reliably documented characteristic that Dominions have extreme amounts of free stroke compared to Code RSCs. Are you...

Wait I thought it was a well known and reliably documented characteristic that Dominions have extreme amounts of free stroke compared to Code RSCs. Are you telling me that that's not correct, and that they appear to have less?

I mean, both of them have contact point / free stroke adjustments, are we measuring at the extremes? 

AgrAde
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5/14/2025 3:42pm Edited Date/Time 5/14/2025 4:20pm

I'm just poking fun at Jakub for telling me I'm wrong about my own experience with my brakes.

I've just left the free stroke as it came. Code RSCs can easily double the amount of free stroke I have, but I don't know how little they can adjust down to.

1
Evil96
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5/15/2025 2:49am

Question for you all nerds

Back from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect pm180 frame/fork pm +40 or 23 adapter and run 220/203 pads were biting perfect at the top of the rotor, great match.

Switched to Hope, running the same bike and fork, 203 rotors so the H adapter +23mm

Noticed the pads were biting quite low and on their “tech book” Hope states there should be 0.5 1mm max of un “bitten” rotor.

While it seems a bit odd I measured mines and I was 1.76mm off, and on another bike I installed some 200 rotors today It was sitting so low the rotor was actually touching the top of the caliper with the proper +20 adapter, had to move it to +23 to have the pads at the correct height.

Now back on my bike, I put some 1.47 washers under the caliper and now the pads and rotors are a perfect match,

So I’m wondering where’s the issue here?

Hope caliper sitting too low?

I’d love to run everything flush with no washers especially since they don’t have any proper facing or anyrhing, thankfully these brakes are easy to align but ideally I’d have the calipers flush on the adapters and nothing else. 

IMG 9565.jpeg?VersionId=BtqtTtIMG 9568
2
HexonJuan
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5/15/2025 7:57am Edited Date/Time 5/15/2025 1:05pm
Evil96 wrote:
Question for you all nerdsBack from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect...

Question for you all nerds

Back from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect pm180 frame/fork pm +40 or 23 adapter and run 220/203 pads were biting perfect at the top of the rotor, great match.

Switched to Hope, running the same bike and fork, 203 rotors so the H adapter +23mm

Noticed the pads were biting quite low and on their “tech book” Hope states there should be 0.5 1mm max of un “bitten” rotor.

While it seems a bit odd I measured mines and I was 1.76mm off, and on another bike I installed some 200 rotors today It was sitting so low the rotor was actually touching the top of the caliper with the proper +20 adapter, had to move it to +23 to have the pads at the correct height.

Now back on my bike, I put some 1.47 washers under the caliper and now the pads and rotors are a perfect match,

So I’m wondering where’s the issue here?

Hope caliper sitting too low?

I’d love to run everything flush with no washers especially since they don’t have any proper facing or anyrhing, thankfully these brakes are easy to align but ideally I’d have the calipers flush on the adapters and nothing else. 

IMG 9565.jpeg?VersionId=BtqtTtIMG 9568

If you have em, I'd try another brand of adapters and see if the problem is still present. The calipers are near net forged, so I'd be hard pressed thinking they'd get terribly outta tolerance during machining. What I could see happening is an L adapter being mislabeled/machined with an H on it, since the needed amount of spacers pretty well perfectly aligns with the radial difference between a 200 and 203mm rotor.

 

***Edited for clarity. Will no longer post/reply before coffee kicks in****

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Jakub_G
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5/15/2025 8:51am
Eae903 wrote:

I mean, both of them have contact point / free stroke adjustments, are we measuring at the extremes? 

Only one of them is meant to be adjusted and actually does good job at that. The other one, well, not so much.

Jakub_G
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5/15/2025 8:55am
Evil96 wrote:
Question for you all nerdsBack from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect...

Question for you all nerds

Back from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect pm180 frame/fork pm +40 or 23 adapter and run 220/203 pads were biting perfect at the top of the rotor, great match.

Switched to Hope, running the same bike and fork, 203 rotors so the H adapter +23mm

Noticed the pads were biting quite low and on their “tech book” Hope states there should be 0.5 1mm max of un “bitten” rotor.

While it seems a bit odd I measured mines and I was 1.76mm off, and on another bike I installed some 200 rotors today It was sitting so low the rotor was actually touching the top of the caliper with the proper +20 adapter, had to move it to +23 to have the pads at the correct height.

Now back on my bike, I put some 1.47 washers under the caliper and now the pads and rotors are a perfect match,

So I’m wondering where’s the issue here?

Hope caliper sitting too low?

I’d love to run everything flush with no washers especially since they don’t have any proper facing or anyrhing, thankfully these brakes are easy to align but ideally I’d have the calipers flush on the adapters and nothing else. 

IMG 9565.jpeg?VersionId=BtqtTtIMG 9568

As long as the top edge of rotor is not below the top edge of the pad it's fine,your last picture looks bang on the money to be honest.

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AndehM
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5/15/2025 9:06am
Evil96 wrote:
Question for you all nerdsBack from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect...

Question for you all nerds

Back from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect pm180 frame/fork pm +40 or 23 adapter and run 220/203 pads were biting perfect at the top of the rotor, great match.

Switched to Hope, running the same bike and fork, 203 rotors so the H adapter +23mm

Noticed the pads were biting quite low and on their “tech book” Hope states there should be 0.5 1mm max of un “bitten” rotor.

While it seems a bit odd I measured mines and I was 1.76mm off, and on another bike I installed some 200 rotors today It was sitting so low the rotor was actually touching the top of the caliper with the proper +20 adapter, had to move it to +23 to have the pads at the correct height.

Now back on my bike, I put some 1.47 washers under the caliper and now the pads and rotors are a perfect match,

So I’m wondering where’s the issue here?

Hope caliper sitting too low?

I’d love to run everything flush with no washers especially since they don’t have any proper facing or anyrhing, thankfully these brakes are easy to align but ideally I’d have the calipers flush on the adapters and nothing else. 

IMG 9565.jpeg?VersionId=BtqtTtIMG 9568

It looks to me like with the extra spacers you're definitely too high.  Look at the center of the pistons vs. center of the rotor radius.  Center of your pistons right now is right on the 3rd row of holes (in the 4-hole pattern), instead of in between the 2nd & 3rd rows of holes.

Eae903
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5/15/2025 12:50pm
Eae903 wrote:

I mean, both of them have contact point / free stroke adjustments, are we measuring at the extremes? 

Jakub_G wrote:

Only one of them is meant to be adjusted and actually does good job at that. The other one, well, not so much.

For some reason, I assume you mean the codes adjustment being the one that works but I've had good luck with both. 

brash
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5/15/2025 3:14pm

talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)

can it be done with a file and a calibrated eyeball or do you need special tools?

1
ballz
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5/15/2025 3:55pm
brash wrote:
talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)can it be done with a file and a calibrated...

talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)

can it be done with a file and a calibrated eyeball or do you need special tools?

Yes.

1
Eae903
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5/15/2025 5:43pm
brash wrote:
talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)can it be done with a file and a calibrated...

talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)

can it be done with a file and a calibrated eyeball or do you need special tools?

ballz wrote:

Yes.

Facing is best done with special tools that ensure that the mount is level when you're done, but if you're really careful and don't mind ruining the mounts if you mess up, you could try to do it with a file. 

5
29
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5/15/2025 10:47pm

Isn’t the whole point of facing to get a completely level surface in a 90° angle to the the thread?


Any time I filed something I couldn’t get it completely flat without rounding off any corners, and I doubt you could get it at the right angle by just eyeballing. 

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Primoz
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5/15/2025 10:52pm
29 wrote:
Isn’t the whole point of facing to get a completely level surface in a 90° angle to the the thread?Any time I filed something I couldn’t...

Isn’t the whole point of facing to get a completely level surface in a 90° angle to the the thread?


Any time I filed something I couldn’t get it completely flat without rounding off any corners, and I doubt you could get it at the right angle by just eyeballing. 

Correct. 

1
brash
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5/16/2025 12:36am
29 wrote:
Isn’t the whole point of facing to get a completely level surface in a 90° angle to the the thread?Any time I filed something I couldn’t...

Isn’t the whole point of facing to get a completely level surface in a 90° angle to the the thread?


Any time I filed something I couldn’t get it completely flat without rounding off any corners, and I doubt you could get it at the right angle by just eyeballing. 

thats why I asked the question before I start hacking at my 38's with a file from 1845 I inherited.

2
mannebask
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5/16/2025 12:50am

Ok. So after being on Shimano brakes (SLX, XT 4-pots and Saints) for an eternity I picked up a bike with Hayes Dominion A4. First impressions are that these are some nice feeling brakes and nice action and good stopping power, but no wow factor for me, at least for first impressions. I will try some other pads and also run them in the bikepark for more extensive testing for sure. 

2
Primoz
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5/16/2025 4:07am Edited Date/Time 5/16/2025 4:08am

No wow factor in the parking lot or actually using them to stop going down a trail? Shimanos are VERY wow in the parking lot because of their on-off characteristic.

@brash yeah, don't...

2
5/16/2025 5:06am Edited Date/Time 5/16/2025 5:12am
brash wrote:
talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)can it be done with a file and a calibrated...

talk to me about facing brake mounts, imagine I know nothing about it (which is true lol)

can it be done with a file and a calibrated eyeball or do you need special tools?

It can be done with a file, but 99% of the population lacks the skill to do that properly. The end result would most likely be neither flat nor perpendicular to the mounting bolts. Both issues would make brake setup more difficult. 

I did my fork with a fine file, but I build prototype firearms parts for a living so I have above average skill with fitting parts with a file. 

3
boozed
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5/16/2025 5:33am

From my position of more or less complete ignorance on the matter, I thought the intention of facing the brake mounts was to get them to be perpendicular to the brake disc, not the mounting bolt axes?

3
Primoz
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5/16/2025 5:44am Edited Date/Time 5/16/2025 5:45am

Ideally one is the same as the other anyway... But yeah, the intention is for the face to be perpendicular to the wheel axle (which is how the tools look like as well). If the bolt is not perpendicular you can still use a cup and cone washer to adapt to it, but if the mounting face is not perpendicular, the caliper (or adapter) will not sit perpendicular either. 

2
mannebask
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5/16/2025 6:49am
Primoz wrote:
No wow factor in the parking lot or actually using them to stop going down a trail? Shimanos are VERY wow in the parking lot because...

No wow factor in the parking lot or actually using them to stop going down a trail? Shimanos are VERY wow in the parking lot because of their on-off characteristic.

@brash yeah, don't...

I took them down a few of my steepest gnarliest trails in my local woods. Almost rammed a tree when i pulled the brakes and expecting the bite point to come real fast. 

Anyhow, first test means nothing. I'm still sure they're great so I will give it more time. 

1
Eae903
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5/16/2025 7:01am

Keep in mind that when you are facing the mounts, you are removing material. Hopefully it's not too much but you might need to modify your spacers afterwards to make sure the pads contact correctly, like those hope brakes from before. 

3
mtbjoe
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5/19/2025 2:29am

Anyone use the hayes dominion hoses on hope tech v4? Found some for practically free and they are super stiff and beefy. ID is 2.5mm vs 2.1mm for the standard hoses. The standard hope barb seems to be too small but would it work with an olive compressing? Any idea on how this would change the character of the brakes? 

1

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