Squealing front Disk brake

[Mark Cleary]

My Shimano road hydraulic front brake is really squealing. I put new identical pads in and really over past 400 miles they have gotten worse. I cleaned the rotor with ISO Alcohol. I clean the pads with it and even used some sandpaper to get them clean. To me they look clean not contaminated, but that is what they claim is the problem. The rotor is true the brake pads don't rub but sort of hit the side of one of the pads, but just minor and it doesn't cause the wheel to slow down just spinning it. I have come to believe with small tolerances of clearance between pads can cause a slight rub nothing drastic for sure. I am at a loss.
Deacon mark

[Tom Kunich]

On Thursday, August 3, 2023 at 7:40:36 AM UTC-7, Mark Cleary wrote:
> My Shimano road hydraulic front brake is really squealing. I put new identical pads in and really over past 400 miles they have gotten worse. I cleaned the rotor with ISO Alcohol. I clean the pads with it and even used some sandpaper to get them clean. To me they look clean not contaminated, but that is what they claim is the problem. The rotor is true the brake pads don't rub but sort of hit the side of one of the pads, but just minor and it doesn't cause the wheel to slow down just spinning it. I have come to believe with small tolerances of clearance between pads can cause a slight rub nothing drastic for sure. I am at a loss.
> Deacon mark

There are several materials that the pads can be made from. The racing pads are normally metallic and are most prone to that squealing. I'm sure that Andrew can sell you different pads than what you presently have and give you any other ideas. But in my experience, putting the brakes on hard always results in squealing.

[Mark Cleary]

I am using organic resin pads. Supposed to be the least amount of noise. Metallic cause the most noise I understand but I live in the flatlands and resin pads are the standard here. I am willing to try metal or ceramic pads but my understanding is they are worse noise makers.
Deacon mark

[Tom Kunich]

On flat ground the harder pads don't howl as much. The squealing comes from the catching and releasing of the pad against the disk. I always would check the "fit" of the pads on the retaining screw. The looser the fit, the more likely it is to make squeals, though there are a lot of things involved. The coarseness of the finish on the disk, the number of cooling slots, the pad material and the fit of the pad in the caliper (actuator) and the distance the caliper is into the disk.

[Tom Kunich]

By the way, I just remembered - I could tell when the brake was going to squeal through practice and I would brake faster or slower than that point. You probably have the same ability.

[Roger Meriman]

Squealing is generally muck, and also in general brakes like to be used ie
in general harder than gentle. Which will generally clean and silent disks.

Talking of which in general disks don’t at least in my experience like
products even disk cleaning products. I wash off with water and change pads
on my bikes that’s it.

If a pad has got contaminated then that’s probably game over really for the
pads.

Roger Merriman

[Lou Holtman]

On Thursday, August 3, 2023 at 4:40:36 PM UTC+2, Mark Cleary wrote:
> My Shimano road hydraulic front brake is really squealing. I put new identical pads in and really over past 400 miles they have gotten worse. I cleaned the rotor with ISO Alcohol. I clean the pads with it and even used some sandpaper to get them clean. To me they look clean not contaminated, but that is what they claim is the problem. The rotor is true the brake pads don't rub but sort of hit the side of one of the pads, but just minor and it doesn't cause the wheel to slow down just spinning it. I have come to believe with small tolerances of clearance between pads can cause a slight rub nothing drastic for sure. I am at a loss.
> Deacon mark

Clean your rotor with iso propanol using a scotch brite and sand your pads with fresh sandpaper after that you have to bed in the pads/rotor again properly.

Lou

[Catrike Rider]

On Thu, 03 Aug 2023 18:01:14 GMT, Roger Meriman <ro...@sarlet.com>
wrote:

My resin pads squeal horribly when they're wet.

[Mark Cleary]

Yes when wet I am pretty sure any pad will squeal.

Lou, I did take the pad and run in on my disk sander and that did not help. I will try the scotch bite pad trick though.

Another thought is the rotors. They are 160 and I don't want to replace it as such nothing seems wrong but would that possibly help. I note that rotors are all over the place in price. Some a low as $12 to almost $80 for a rotor. I have centerlock and are more expensive rotors necessarily better?
Deacon mark

[AMuzi]

On 8/3/2023 1:37 PM, Mark Cleary wrote:

> On Thursday, August 3, 2023 at 1:09:56 PM UTC-5, Catrike Rider wrote:
>> On Thu, 03 Aug 2023 18:01:14 GMT, Roger Meriman <ro...@sarlet.com>
>> wrote:
>>> Mark Cleary <deaco...@gmail.com> wrote:
>>>> My Shimano road hydraulic front brake is really squealing. I put new
>>>> identical pads in and really over past 400 miles they have gotten worse.
>>>> I cleaned the rotor with ISO Alcohol. I clean the pads with it and even
>>>> used some sandpaper to get them clean. To me they look clean not
>>>> contaminated, but that is what they claim is the problem. The rotor is
>>>> true the brake pads don't rub but sort of hit the side of one of the
>>>> pads, but just minor and it doesn't cause the wheel to slow down just
>>>> spinning it. I have come to believe with small tolerances of clearance
>>>> between pads can cause a slight rub nothing drastic for sure. I am at a loss.
>>>> Deacon mark
>>>>
>>> Squealing is generally muck, and also in general brakes like to be used ie
>>> in general harder than gentle. Which will generally clean and silent disks.
>>>

>>> Talking of which in general disks don’t at least in my experience like

>>> products even disk cleaning products. I wash off with water and change pads

>>> on my bikes that’s it.
>>>
>>> If a pad has got contaminated then that’s probably game over really for the

>>> pads.
>>>
>>> Roger Merriman
>> My resin pads squeal horribly when they're wet.
>
> Yes when wet I am pretty sure any pad will squeal.
>
> Lou, I did take the pad and run in on my disk sander and that did not help. I will try the scotch bite pad trick though.
>
> Another thought is the rotors. They are 160 and I don't want to replace it as such nothing seems wrong but would that possibly help. I note that rotors are all over the place in price. Some a low as $12 to almost $80 for a rotor. I have centerlock and are more expensive rotors necessarily better?
> Deacon mark
>

Carbon center carrier, interesting patterns but no
difference in performance.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[Frank Krygowski]

It occurs to me, car disc brakes shoes are often installed with an
anti-squeal goop of some kind on the backside. I've never read an
explanation, but I've assumed it adds some damping to any vibration.

But I don't think I've heard of that for bike disc brakes.

--
- Frank Krygowski

[Frank Krygowski]

So, another reason to not love disc brakes.

--
- Frank Krygowski

[Lou Holtman]

Key word is bedding in properly after you ‘resetted’ the pads and rotor by sanding the pads and cleaning the rotor thoroughly with iso propanol and scrotch brite.

Lou

[Lou Holtman]

It is a ten minutes job. After the downpour ride yesterday it took me more time to clean my brake surfaces of my rims and pulling out the aluminum particles out of my brake pads of my front rim brakes. Yes I know, you don’t ride when it is raining.

Lou

[Catrike Rider]

On Thu, 3 Aug 2023 13:29:19 -0700 (PDT), Lou Holtman
<lou.h...@gmail.com> wrote:

>On Thursday, August 3, 2023 at 8:58:08?PM UTC+2, Frank Krygowski wrote:
>> On 8/3/2023 2:04 PM, Lou Holtman wrote:

>> > On Thursday, August 3, 2023 at 4:40:36?PM UTC+2, Mark Cleary wrote:
>> >> My Shimano road hydraulic front brake is really squealing. I put new identical pads in and really over past 400 miles they have gotten worse. I cleaned the rotor with ISO Alcohol. I clean the pads with it and even used some sandpaper to get them clean. To me they look clean not contaminated, but that is what they claim is the problem. The rotor is true the brake pads don't rub but sort of hit the side of one of the pads, but just minor and it doesn't cause the wheel to slow down just spinning it. I have come to believe with small tolerances of clearance between pads can cause a slight rub nothing drastic for sure. I am at a loss.
>> >> Deacon mark
>> >
>> > Clean your rotor with iso propanol using a scotch brite and sand your pads with fresh sandpaper after that you have to bed in the pads/rotor again properly.
>> So, another reason to not love disc brakes.
>>
>> --
>> - Frank Krygowski
>
>It is a ten minutes job. After the downpour ride yesterday it took me more time to clean my brake surfaces of my rims and pulling out the aluminum particles out of my brake pads of my front rim brakes. Yes I know, you don’t ride when it is raining.
>
>Lou

I've never cleaned my brake pads. Once in a while, maybe two or three
times a year, I've cleaned the disks.

[Roger Meriman]

I have if they have got contaminants ie oil be that bike or road muck, but
it’s less than a year job.

Wash bikes after use Gravel/MTB and change pads that’s it, commute bike
doesn’t even get cleaned! As long as they are used they are absolutely fine
and don’t need any cleaning fluids or what not.

Just making life difficult for one’s self really.

Roger Merriman

[Roger Meriman]

Once the rotor is clear of stuff be it water or muck I find it’s quiet,
possible not absolutely silent but certainly not squealing. On the road at
least, on the trails wet days get grit which grinds though squealing is
relatively rare personally.

>
> Lou, I did take the pad and run in on my disk sander and that did not
> help. I will try the scotch bite pad trick though.
>
> Another thought is the rotors. They are 160 and I don't want to replace
> it as such nothing seems wrong but would that possibly help. I note that
> rotors are all over the place in price. Some a low as $12 to almost $80
> for a rotor. I have centerlock and are more expensive rotors necessarily better?
> Deacon mark
>

Define better? Rotors last for ages so I’ve only replaced one set. Almost
certainly into marginal gains for most folks.

Roger Merriman

[Roger Meriman]

My wife never managed this so I used to do it for her! Sometimes giving her
some pads I’d part worn which seemed to do the trick.

And she rode so gently and brakes so gently that wear is minimal.

Roger Merriman

[Tom Kunich]

There a speed and braking force that causes that howling. I was usually able to squeeze harder or less so on the brake to stay out of that noise zone.

[Roger Meriman]

Found that more with rim brakes, to be honest. But yes sometimes if it’s
wet mucky if one is gentle it will be quiet, this said needs to clean the
rotor/pads and so it’s only delaying it, ie what it likes is to be used.

Roger Merriman

[Mark Cleary]

Ok today on my 63 mile ride not much braking and if I slowed down a bit with the ( front is the squeaker0 it would not make any noise. However, as I increased braking power to slopping, they squeaked still pretty loud. They certainly do the job and grab the rotor and stop no performance problems, but it is Illinois no mountains. I tried a few times to get going then let them squeak like made stopping to see if putting more force on would eventually stop the noise. This had zero effect.

Somehow, I think it could be the rotor is not quite flat but there is no brake rub if I just spin the wheel. The rotor is not exactly true but pretty little amount of movement. Nothing you can see unless you look very closely spinning wheel in good light. Then it is almost nothing has to be less even 1/2 of a mm of movement. By wheel truing standards it would be completely true.

I could try new pads and/or a different rotor but that cost money. My guess is a 2 piece rotor is going to go for over $40. Frankly the noise does not really mother me a solo rider in the middle of nowhere and the brake lever action at the handlebars is perfect. But stopping in my driveway at home I can wake the neighbors up if it is early. I am up for some real technical information on what to do, including live with it.
Deacon Mark

[Tom Kunich]

I did not have a lot of problems with the disk setups beyond the fact that they were too powerful and too likely to lock the wheels if you were applying the brakes and hit a bump. Rim brakes seemed just as powerful if properly adjusted but a lot less sensitive to bumps etc.

[Roger Meriman]

I suspect your overthinking it, as long as it brakes fine. In general they
don’t like being fussed with and really dislike oils and so on, and
certainly in my experience aren’t wildly keen on cleaning products even if
they are apparently for cleaning disks!

Ie wash them off as with bike but keep chain oil well away!

[Frank Krygowski]

A badly squealing brake would bother me terribly, whether it brakes fine
or not.

There was one club ride where my rim brakes suddenly began squealing
much like Mark described. It was embarrassing, because it was a rather
somber memorial ride for a good friend and club member who had passed away.

So at one of the many stops on the ride, I took out my multi-tool and
quickly added a bit of toe in to the brake shoes, curing the problem in
short order.

I prefer equipment whose problems are easy to diagnose.

--
- Frank Krygowski

[Lou Holtman]

Like you did Mark should fix the problem. Squealing disks brakes in the dry is unnecessary.

Lou

[Mark Cleary]

Pretty hard to toe in a disk brake but I am open to how. Squeaking all morning again maybe new rotors and pads.
Deacon Mark

[Lou Holtman]

Before you buy new rotors take of your rotors, clean them with iso propanol and sand them using a sanding block on a flat surface with new 320-400 grit sandpaper in a circular motion and clean them afterwards again with iso propanol. New rotors are not any better than the treated one except if they are warped. I would buy new resin pads and bed them in for god’s sake. Google bedding in disk brakes. Proper bedding in should be a good work out if you have only flat terrain.

Lou

[Mark Cleary]

How do you bed yours in Lou I have watch video's of it curious on your end your approach. I never did that when I got the bike new.
Deacon Mark

[Lou Holtman]

I think I use the method I saw on the SRAM site. Accelerate to 20 km/hr and then brake hard and release the brakes just before you come to a stop (important). Repeat that twenty times, (two zero). Then accelerate to 30 Km/hr and brake hard and also release the brakes just before you come to a stop. Repeat that ten times (one zero). Do all that within a short period of time. What I understand is that the pads have to go through some heat cycles and some pad material get deposited on the rotor. What I notice is that at the start the brakes can (not always) start squealing just before you come to a stop and disappears when you go through the bedding proces. Also you notice a significant increase in stopping power and modulation. I use it as an interval training and it feels also like it. It helps if you have a long downhill but you definitely don’t do that with a headwind. What I most of the time do is wait for a windy day and do it when the wind blows in my back. What is killing for the brakes when you changed the pads is just riding along and only brake gently before each corner.

Lou

[Lou Holtman]

Oh I forgot to mention before I put in new pads and do the bedding in I scotchbrite the rotor with iso propanol and go with the new pads over a sheet of fresh sandpaper (grit 150-180). Don’t touch rotor and pads with greasy fingers after that.

Lou

[Tom Kunich]

When mine would squeal it generally meant that I had to readjust them. But they did always make some noise.

[Tom Kunich]

The brakes on my gravel bike are those self contained hydraulics manually actuated and they don't make any noise. I assume that is because the cable actuation allows you to have wider clearances.

[Roger Meriman]

It’s means that the pad is not happy be that not bedding in or contaminated
by oil or so on

> There was one club ride where my rim brakes suddenly began squealing
> much like Mark described. It was embarrassing, because it was a rather
> somber memorial ride for a good friend and club member who had passed away.
>
> So at one of the many stops on the ride, I took out my multi-tool and
> quickly added a bit of toe in to the brake shoes, curing the problem in
> short order.
>
> I prefer equipment whose problems are easy to diagnose.
>

Personally I change pads and that’s it, some folks need to bed in the pads,
I don’t as I’m heavy and tend to use the brakes fairly powerfully and in
general my riding will do that quickly so I don’t need to.

Roger Merriman

[Roger Meriman]

Not that I’m aware of, some of the latest brakes have more clearance so
less grittiness, ie less grinding noises that one might occasionally hear
on Sandy type terrain if wet at least until you brake next.

Roger Merriman

[AMuzi]

On 8/9/2023 11:30 AM, Mark Cleary wrote:

> On Wednesday, August 9, 2023 at 10:47:57 AM UTC-5, Frank Krygowski wrote:
>> On 8/9/2023 5:24 AM, Roger Meriman wrote:
>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>> On Tuesday, August 8, 2023 at 12:32:16 PM UTC-5, Roger Meriman wrote:
>>>>> Tom Kunich <cycl...@gmail.com> wrote:

>>>>>> On Thursday, August 3, 2023 at 2:26:23 PM UTC-7, Roger Meriman wrote:
>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>>> On Thursday, August 3, 2023 at 1:09:56 PM UTC-5, Catrike Rider wrote:
>>>>>>>>> On Thu, 03 Aug 2023 18:01:14 GMT, Roger Meriman <ro...@sarlet.com>
>>>>>>>>> wrote:
>>>>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:
>>>>>>>>>>> My Shimano road hydraulic front brake is really squealing. I put new
>>>>>>>>>>> identical pads in and really over past 400 miles they have gotten worse.
>>>>>>>>>>> I cleaned the rotor with ISO Alcohol. I clean the pads with it and even
>>>>>>>>>>> used some sandpaper to get them clean. To me they look clean not
>>>>>>>>>>> contaminated, but that is what they claim is the problem. The rotor is
>>>>>>>>>>> true the brake pads don't rub but sort of hit the side of one of the
>>>>>>>>>>> pads, but just minor and it doesn't cause the wheel to slow down just
>>>>>>>>>>> spinning it. I have come to believe with small tolerances of clearance
>>>>>>>>>>> between pads can cause a slight rub nothing drastic for sure. I am at a loss.
>>>>>>>>>>> Deacon mark
>>>>>>>>>>>
>>>>>>>>>> Squealing is generally muck, and also in general brakes like to be used ie
>>>>>>>>>> in general harder than gentle. Which will generally clean and silent disks.
>>>>>>>>>>

>>>>>>>>>> Talking of which in general disks don’t at least in my experience like

>>>>>>>>>> products even disk cleaning products. I wash off with water and change pads

>>>>>>>>>> on my bikes that’s it.
>>>>>>>>>>
>>>>>>>>>> If a pad has got contaminated then that’s probably game over really for the

>>>>>>>>>> pads.
>>>>>>>>>>
>>>>>>>>>> Roger Merriman
>>>>>>>>> My resin pads squeal horribly when they're wet.
>>>>>>>>
>>>>>>>> Yes when wet I am pretty sure any pad will squeal.

>>>>>>> Once the rotor is clear of stuff be it water or muck I find it’s quiet,

>>>>>>> possible not absolutely silent but certainly not squealing. On the road at
>>>>>>> least, on the trails wet days get grit which grinds though squealing is
>>>>>>> relatively rare personally.
>>>>>>>>
>>>>>>>> Lou, I did take the pad and run in on my disk sander and that did not
>>>>>>>> help. I will try the scotch bite pad trick though.
>>>>>>>>
>>>>>>>> Another thought is the rotors. They are 160 and I don't want to replace
>>>>>>>> it as such nothing seems wrong but would that possibly help. I note that
>>>>>>>> rotors are all over the place in price. Some a low as $12 to almost $80
>>>>>>>> for a rotor. I have centerlock and are more expensive rotors necessarily better?
>>>>>>>> Deacon mark
>>>>>>>>

>>>>>>> Define better? Rotors last for ages so I’ve only replaced one set. Almost

>>>>>>> certainly into marginal gains for most folks.
>>>>>>>
>>>>>>> Roger Merriman
>>>>>>
>>>>>> There a speed and braking force that causes that howling. I was usually
>>>>>> able to squeeze harder or less so on the brake to stay out of that noise zone.
>>>>>>

>>>>> Found that more with rim brakes, to be honest. But yes sometimes if it’s

>>>>> wet mucky if one is gentle it will be quiet, this said needs to clean the

>>>>> rotor/pads and so it’s only delaying it, ie what it likes is to be used.

Just as with autos, disc brake squeal is contamination.

That's exacerbated in use as whatever it is glazes into the
pad and rotor once hot. As others have suggested an abrasive
such as Scotch Brite with disc brake cleaner is a good start.

[Lou Holtman]

In order to keep the brake surface properties they have to stay clean(ish) or they have to wear so that the surfaces are renewed. This applies not only for disk brakes btw. Wear can be accomplish by hard braking and/or use of less wear resistant pads. I imagine that Mark only has to brake gently given the fact that his routes don't have many corners and like here the terrain is flat(ish). In that case contamination builds up and as Andrew mentioned glazes into the pads over time. Good practice for me is to take out the pads regularly when cleaning the bike in the stand and rub the surface of the pads over a clean sheet of sandpaper to get rid of the shiny black layer which is basically build up muck. Be reluctant to clean the rotors too thoroughly after bedding in because you want to keep that layer of brake pad material on the rotors. Soapy water is good enough for normal maintenance. Try to avoid riding through puddles of water with a visible oily layer. F*cking tractors most of the times.

Lou

[Mark Cleary]

Lou you are spot on my riding. I can ride 100 miles and never need to do anything but feather the brakes.

But the big news is I think I may have solved the problem. Today after my ride which included the noisy brakes, I removed the pads and did a very deep sanding of the pads with 220 grit. I notice the pads seemed to be a bit glazed over and shiny if that is what is meant by contamination/glaze. I figure at this point no worry on if I sand too much. As it turns out the sandpaper really does not noticeably take a lot of material off the pad, but I went at it very vigorously. I could see lots of black stuff on the light sandpaper. Not sure if it was the pad material so much as maybe the layer of glazed stuff. In any case I put the pad back in and worked the brake. Well, there was no noise at all in the basement on the stand spinning the wheel and stopping it and none putting it on the floor and apply brake with force of bike movement forward. Previously even that would cause a howling. So will be interested to see how it goes tomorrow but I think I may have it under control. I did not clean or touch the rotor this time as it look just like the back rotor in terms of markings on the brake track.

Next question is do I have to attempt to re-bed the pad since I did this, my guess is no since rotor already has been used.
Deacon Mark

[Frank Krygowski]

Reading all the above, I'm liking my rim brakes more and more!

--
- Frank Krygowski

[Mark Cleary]

I actually like the hydraulic brakes. Rim brakes cause to rim vibrations when stopping hard, that sometimes happens if you have a rim with a seam that is not quite flat. Also the rim can get any kind of deformity and it will show up in braking the bike. It is not a huge problem but I don't like it a bit. Rim brakes are fine but I am finding I like the hrydraulics very much. I must note that the rear brake has never cause and issue of any kind. It has work well all situations.
Deacon Mark

[Roger Meriman]

That fundamental is the issue my wife did that hence I would give her my
part worn pads as they seemed more resistant than if I just broke them in.

I don’t even need to break them in as my riding will do that.

>
> But the big news is I think I may have solved the problem. Today after my
> ride which included the noisy brakes, I removed the pads and did a very
> deep sanding of the pads with 220 grit. I notice the pads seemed to be a
> bit glazed over and shiny if that is what is meant by
> contamination/glaze. I figure at this point no worry on if I sand too
> much. As it turns out the sandpaper really does not noticeably take a lot
> of material off the pad, but I went at it very vigorously. I could see
> lots of black stuff on the light sandpaper. Not sure if it was the pad
> material so much as maybe the layer of glazed stuff. In any case I put
> the pad back in and worked the brake. Well, there was no noise at all in
> the basement on the stand spinning the wheel and stopping it and none
> putting it on the floor and apply brake with force of bike movement
> forward. Previously even that would cause a howling. So will be
> interested to see how it goes tomorrow but I think I may have it under
> control. I did not clean or touch the rotor this time as it look just
> like the back rotor in terms of markings on the brake track.
>
> Next question is do I have to attempt to re-bed the pad since I did this,
> my guess is no since rotor already has been used.
> Deacon Mark
>

Sounds good perhaps a maintenance firm stop now and then!

Roger Merriman

[Roger Meriman]

Mark is realistically a outlier and arguably be better suited by rim brakes
by sounds of things though bikes are more than just one component, sum of
the total and all that!

Roger Merriman

[Catrike Rider]

On Thu, 10 Aug 2023 11:53:55 -0400, Frank Krygowski
<frkr...@sbcglobal.net> wrote:

>On 8/10/2023 7:35 AM, Lou Holtman wrote:

>> On Thursday, August 10, 2023 at 12:33:51?AM UTC+2, AMuzi wrote:
>>> On 8/9/2023 11:30 AM, Mark Cleary wrote:

>>>> On Wednesday, August 9, 2023 at 10:47:57 AM UTC-5, Frank Krygowski wrote:
>>>>> On 8/9/2023 5:24 AM, Roger Meriman wrote:
>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>> On Tuesday, August 8, 2023 at 12:32:16 PM UTC-5, Roger Meriman wrote:
>>>>>>>> Tom Kunich <cycl...@gmail.com> wrote:

>>>>>>>>> On Thursday, August 3, 2023 at 2:26:23 PM UTC-7, Roger Meriman wrote:
>>>>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>>>>>> On Thursday, August 3, 2023 at 1:09:56 PM UTC-5, Catrike Rider wrote:
>>>>>>>>>>>> On Thu, 03 Aug 2023 18:01:14 GMT, Roger Meriman <ro...@sarlet.com>
>>>>>>>>>>>> wrote:
>>>>>>>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:
>>>>>>>>>>>>>> My Shimano road hydraulic front brake is really squealing. I put new
>>>>>>>>>>>>>> identical pads in and really over past 400 miles they have gotten worse.
>>>>>>>>>>>>>> I cleaned the rotor with ISO Alcohol. I clean the pads with it and even
>>>>>>>>>>>>>> used some sandpaper to get them clean. To me they look clean not
>>>>>>>>>>>>>> contaminated, but that is what they claim is the problem. The rotor is
>>>>>>>>>>>>>> true the brake pads don't rub but sort of hit the side of one of the
>>>>>>>>>>>>>> pads, but just minor and it doesn't cause the wheel to slow down just
>>>>>>>>>>>>>> spinning it. I have come to believe with small tolerances of clearance
>>>>>>>>>>>>>> between pads can cause a slight rub nothing drastic for sure. I am at a loss.
>>>>>>>>>>>>>> Deacon mark
>>>>>>>>>>>>>>
>>>>>>>>>>>>> Squealing is generally muck, and also in general brakes like to be used ie
>>>>>>>>>>>>> in general harder than gentle. Which will generally clean and silent disks.
>>>>>>>>>>>>>

>>>>>>>>>>>>> Talking of which in general disks don’t at least in my experience like

>>>>>>>>>>>>> products even disk cleaning products. I wash off with water and change pads

>>>>>>>>>>>>> on my bikes that’s it.
>>>>>>>>>>>>>
>>>>>>>>>>>>> If a pad has got contaminated then that’s probably game over really for the

>>>>>>>>>>>>> pads.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Roger Merriman
>>>>>>>>>>>> My resin pads squeal horribly when they're wet.
>>>>>>>>>>>
>>>>>>>>>>> Yes when wet I am pretty sure any pad will squeal.

>>>>>>>>>> Once the rotor is clear of stuff be it water or muck I find it’s quiet,

>>>>>>>>>> possible not absolutely silent but certainly not squealing. On the road at
>>>>>>>>>> least, on the trails wet days get grit which grinds though squealing is
>>>>>>>>>> relatively rare personally.
>>>>>>>>>>>
>>>>>>>>>>> Lou, I did take the pad and run in on my disk sander and that did not
>>>>>>>>>>> help. I will try the scotch bite pad trick though.
>>>>>>>>>>>
>>>>>>>>>>> Another thought is the rotors. They are 160 and I don't want to replace
>>>>>>>>>>> it as such nothing seems wrong but would that possibly help. I note that
>>>>>>>>>>> rotors are all over the place in price. Some a low as $12 to almost $80
>>>>>>>>>>> for a rotor. I have centerlock and are more expensive rotors necessarily better?
>>>>>>>>>>> Deacon mark
>>>>>>>>>>>

>>>>>>>>>> Define better? Rotors last for ages so I’ve only replaced one set. Almost

>>>>>>>>>> certainly into marginal gains for most folks.
>>>>>>>>>>
>>>>>>>>>> Roger Merriman
>>>>>>>>>
>>>>>>>>> There a speed and braking force that causes that howling. I was usually
>>>>>>>>> able to squeeze harder or less so on the brake to stay out of that noise zone.
>>>>>>>>>

>>>>>>>> Found that more with rim brakes, to be honest. But yes sometimes if it’s

>>>>>>>> wet mucky if one is gentle it will be quiet, this said needs to clean the

>>>>>>>> rotor/pads and so it’s only delaying it, ie what it likes is to be used.

Good, then maybe you should stick with them.

[AMuzi]

On 8/10/2023 10:53 AM, Frank Krygowski wrote:
> On 8/10/2023 7:35 AM, Lou Holtman wrote:

>> On Thursday, August 10, 2023 at 12:33:51 AM UTC+2, AMuzi

>> wrote:
>>> On 8/9/2023 11:30 AM, Mark Cleary wrote:

>>>> On Wednesday, August 9, 2023 at 10:47:57 AM UTC-5,

>>>> Frank Krygowski wrote:
>>>>> On 8/9/2023 5:24 AM, Roger Meriman wrote:
>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>> On Tuesday, August 8, 2023 at 12:32:16 PM

>>>>>>> UTC-5, Roger Meriman wrote:
>>>>>>>> Tom Kunich <cycl...@gmail.com> wrote:

>>>>>>>>> On Thursday, August 3, 2023 at 2:26:23 PM

>>>>>>>>> UTC-7, Roger Meriman wrote:
>>>>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>>>>>> On Thursday, August 3, 2023 at 1:09:56 PM

>>>>>>>>>>>>> Talking of which in general disks don’t

>>>>>>>>>>>>> at least in my experience like
>>>>>>>>>>>>> products even disk cleaning products. I wash
>>>>>>>>>>>>> off with water and change pads

>>>>>>>>>>>>> on my bikes that’s it.

>>>>>>>>>>>>>
>>>>>>>>>>>>> If a pad has got contaminated then

>>>>>>>>>>>>> that’s probably game over really for the

>>>>>>>>>>>>> pads.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Roger Merriman
>>>>>>>>>>>> My resin pads squeal horribly when they're wet.
>>>>>>>>>>>
>>>>>>>>>>> Yes when wet I am pretty sure any pad will squeal.
>>>>>>>>>> Once the rotor is clear of stuff be it water or

>>>>>>>>>> muck I find it’s quiet,

>>>>>>>>>> possible not absolutely silent but certainly not
>>>>>>>>>> squealing. On the road at
>>>>>>>>>> least, on the trails wet days get grit which
>>>>>>>>>> grinds though squealing is
>>>>>>>>>> relatively rare personally.
>>>>>>>>>>>
>>>>>>>>>>> Lou, I did take the pad and run in on my disk
>>>>>>>>>>> sander and that did not
>>>>>>>>>>> help. I will try the scotch bite pad trick though.
>>>>>>>>>>>
>>>>>>>>>>> Another thought is the rotors. They are 160 and I
>>>>>>>>>>> don't want to replace
>>>>>>>>>>> it as such nothing seems wrong but would that
>>>>>>>>>>> possibly help. I note that
>>>>>>>>>>> rotors are all over the place in price. Some a
>>>>>>>>>>> low as $12 to almost $80
>>>>>>>>>>> for a rotor. I have centerlock and are more
>>>>>>>>>>> expensive rotors necessarily better?
>>>>>>>>>>> Deacon mark
>>>>>>>>>>>

>>>>>>>>>> Define better? Rotors last for ages so I’ve

>>>>>>>>>> only replaced one set. Almost
>>>>>>>>>> certainly into marginal gains for most folks.
>>>>>>>>>>
>>>>>>>>>> Roger Merriman
>>>>>>>>>
>>>>>>>>> There a speed and braking force that causes that
>>>>>>>>> howling. I was usually
>>>>>>>>> able to squeeze harder or less so on the brake to
>>>>>>>>> stay out of that noise zone.
>>>>>>>>>
>>>>>>>> Found that more with rim brakes, to be honest. But

>>>>>>>> yes sometimes if it’s

>>>>>>>> wet mucky if one is gentle it will be quiet, this
>>>>>>>> said needs to clean the

>>>>>>>> rotor/pads and so it’s only delaying it, ie

Continuing our recent theme, everything has a cost:
http://www.yellowjersey.org/photosfromthepast/wornrim.jpg

[Sir Ridesalot]

Did that wheel do what mine did when the rim split?

https://live.staticflickr.com/65535/52551330556_077d270564.jpg

All was fine until I took the tire off and then the wheel did this.

https://www.flickr.com/photos/73832500@N00/52551873678/

Than goodness that I was able to ride the thirty kilometers home on that split rim and I took the tire off at home.

Cheers

[John B.]

On Thu, 10 Aug 2023 13:45:20 -0500, AMuzi <a...@yellowjersey.org> wrote:

>On 8/10/2023 10:53 AM, Frank Krygowski wrote:
>> On 8/10/2023 7:35 AM, Lou Holtman wrote:

>>> On Thursday, August 10, 2023 at 12:33:51 AM UTC+2, AMuzi

>>> wrote:
>>>> On 8/9/2023 11:30 AM, Mark Cleary wrote:

>>>>> On Wednesday, August 9, 2023 at 10:47:57 AM UTC-5,

>>>>> Frank Krygowski wrote:
>>>>>> On 8/9/2023 5:24 AM, Roger Meriman wrote:
>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>>> On Tuesday, August 8, 2023 at 12:32:16 PM

>>>>>>>> UTC-5, Roger Meriman wrote:
>>>>>>>>> Tom Kunich <cycl...@gmail.com> wrote:

>>>>>>>>>> On Thursday, August 3, 2023 at 2:26:23 PM

>>>>>>>>>> UTC-7, Roger Meriman wrote:
>>>>>>>>>>> Mark Cleary <deaco...@gmail.com> wrote:

>>>>>>>>>>>> On Thursday, August 3, 2023 at 1:09:56 PM

>>>>>>>>>>>>>> Talking of which in general disks don’t

>>>>>>>>>>>>>> at least in my experience like
>>>>>>>>>>>>>> products even disk cleaning products. I wash
>>>>>>>>>>>>>> off with water and change pads

>>>>>>>>>>>>>> on my bikes that’s it.

>>>>>>>>>>>>>>
>>>>>>>>>>>>>> If a pad has got contaminated then

>>>>>>>>>>>>>> that’s probably game over really for the

>>>>>>>>>>>>>> pads.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Roger Merriman
>>>>>>>>>>>>> My resin pads squeal horribly when they're wet.
>>>>>>>>>>>>
>>>>>>>>>>>> Yes when wet I am pretty sure any pad will squeal.
>>>>>>>>>>> Once the rotor is clear of stuff be it water or

>>>>>>>>>>> muck I find it’s quiet,

>>>>>>>>>>> possible not absolutely silent but certainly not
>>>>>>>>>>> squealing. On the road at
>>>>>>>>>>> least, on the trails wet days get grit which
>>>>>>>>>>> grinds though squealing is
>>>>>>>>>>> relatively rare personally.
>>>>>>>>>>>>
>>>>>>>>>>>> Lou, I did take the pad and run in on my disk
>>>>>>>>>>>> sander and that did not
>>>>>>>>>>>> help. I will try the scotch bite pad trick though.
>>>>>>>>>>>>
>>>>>>>>>>>> Another thought is the rotors. They are 160 and I
>>>>>>>>>>>> don't want to replace
>>>>>>>>>>>> it as such nothing seems wrong but would that
>>>>>>>>>>>> possibly help. I note that
>>>>>>>>>>>> rotors are all over the place in price. Some a
>>>>>>>>>>>> low as $12 to almost $80
>>>>>>>>>>>> for a rotor. I have centerlock and are more
>>>>>>>>>>>> expensive rotors necessarily better?
>>>>>>>>>>>> Deacon mark
>>>>>>>>>>>>

>>>>>>>>>>> Define better? Rotors last for ages so I’ve

>>>>>>>>>>> only replaced one set. Almost
>>>>>>>>>>> certainly into marginal gains for most folks.
>>>>>>>>>>>
>>>>>>>>>>> Roger Merriman
>>>>>>>>>>
>>>>>>>>>> There a speed and braking force that causes that
>>>>>>>>>> howling. I was usually
>>>>>>>>>> able to squeeze harder or less so on the brake to
>>>>>>>>>> stay out of that noise zone.
>>>>>>>>>>
>>>>>>>>> Found that more with rim brakes, to be honest. But

>>>>>>>>> yes sometimes if it’s

>>>>>>>>> wet mucky if one is gentle it will be quiet, this
>>>>>>>>> said needs to clean the

>>>>>>>>> rotor/pads and so it’s only delaying it, ie

But did they squeal?
--
Cheers,

John B.

[Frank Krygowski]

Yes, I remember one ride during which that happened to one guy. It was
the only one I came across. I've got some ancient rims in the basement
where I can see the sidewalls are worn a bit concave, but I replaced those
before anything bad happened.

I'm wondering how common the split failure is. How many here have
experienced it?

- Frank Krygowski

[Wolfgang Strobl]

Am Wed, 9 Aug 2023 11:18:39 -0700 (PDT) schrieb Lou Holtman
<lou.h...@gmail.com>:

> I think I use the method I saw on the SRAM site. Accelerate
> to 20 km/hr and then brake hard and release the brakes just
> before you come to a stop (important). Repeat that twenty
> times, (two zero). Then accelerate to 30 Km/hr and brake
> hard and also release the brakes just before you come to a
> stop. Repeat that ten times (one zero). Do all that within a
> short period of time. What I understand is that the pads
> have to go through some heat cycles and some pad material
> get deposited on the rotor. What I notice is that at the
> start the brakes can (not always) start squealing just
> before you come to a stop and disappears when you go through
> the bedding proces.

That is something I noticed, after I designed and built two new bikes
this spring, based on SRAM components.

<https://www.mystrobl.de/ws/pluspora/plainpostings/20230619t2154-2023_06_19_effelsberg_again.html>


Essentially SRAM Mullet in a titanium frame.

Overall I'm happy with the brakes, the adjustability of the grips and
the low hand strength suits my wife a lot. But squeaking was a nasty
problem at first.

In retrospect, it had two independent causes. On the one hand a somewhat
imprecise positioning of the brake calipers, a problem with the carbon
fork, on the other hand the need to break in the pads in this awkward
way. The first problem was solved by positioning the calipers manually,
by watching the gap. A slight grinding that wasn't even noticeable
while riding resulted in an annoying high frequency squeak when pushing
the wheel or riding slowly, my wife refused to use the bike unless I
changed that.

An initial violent squeaking when braking hard from a normal driving
speed, up to the flapping of the fork, on the other hand, firstly made
an unbearable noise and secondly somewhat reduced the braking effect of
hard braking. This only disappeared after braking in the manner
described plus some longer distance riding. I'm still a bit unhappy with
the sound the brakes make just before they come to a stop, but that's
cosmetics. We've ridden our new bikes less than planned due to the
weather, only about 1700 km so far, but after these initial
complications, everything works as designed.




--
Wir danken für die Beachtung aller Sicherheitsbestimmungen

[Tom Kunich]

When you set rim brakes properly they pretty rapidly wear to the point where they squeal also. So you are always readjusting them. But this is a process that he may not be able to do if he is sanding the hell out of his brake shoes. That is wearing them away. Removing the glazed shouldn't be a difficult job.
+

[Tom Kunich]

I was able to detect the point at which the disc brakes would squeal and work around it. Braking a little harder or softer and avoid the critical frequency.