brake noise on disc brakes could just be the disc.

fooferdoggie

Well-Known Member
OK here is my experiment. my main bike has Magura MT4e e bike brakes with 180 mm rotors. these are very powerful brakes so this may make a difference.


also between brake pad and or disc changes I sanded the pads and disc and cleaned with alcohol and then broke them in with the 20 or so almost stops that are recommended. I also re aligned the calipers between disc changes.



ok my brakes did not make noise for a few weeks and only started when we had heavy rain so they were wet. both front and back squealed when wet. no noise but a ticking the front rotor that has happened on three different rotors. well after several rain rides the back stopped squealing or very little for a short time but the front always did. when I took the bike in for the first tuneup they sanded it all and it was the same squeal when wet but just the front. when I wore out the first pads after about 1600 miles I used the harder pads not the sinterd ones they came with. a little noisy but no biggie. well it rained on the next ride and man the front really squealed but it also had a warble to it. the back was fine a little squeal at first then gone.



well I sanded the disc and put the sintered pads back on the front the squeal was less like normal but the warble was still there but not as loud.



I bought a normal shimano disc and it was a bit warped out of the box. but it only squealed a little in the rain and it would go away. but it would warp randomly in harder braking but it would straighten out on its own. so I bought another magura disc that was the same as the one I have. it only had a light squeal once while raining and that's it.



so disc noise may just be the disc if you have tried everything else. that includes cleaning and sanding the disc and pad realigning the calipers.
 

jaizon

Active Member
I would think that if what you are saying is the case...you'd see a lot more comments about it on EBR. 🤔
 

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
OK here is my experiment. my main bike has Magura MT4e e bike brakes with 180 mm rotors. these are very powerful brakes so this may make a difference.


also between brake pad and or disc changes I sanded the pads and disc and cleaned with alcohol and then broke them in with the 20 or so almost stops that are recommended. I also re aligned the calipers between disc changes.



ok my brakes did not make noise for a few weeks and only started when we had heavy rain so they were wet. both front and back squealed when wet. no noise but a ticking the front rotor that has happened on three different rotors. well after several rain rides the back stopped squealing or very little for a short time but the front always did. when I took the bike in for the first tuneup they sanded it all and it was the same squeal when wet but just the front. when I wore out the first pads after about 1600 miles I used the harder pads not the sinterd ones they came with. a little noisy but no biggie. well it rained on the next ride and man the front really squealed but it also had a warble to it. the back was fine a little squeal at first then gone.



well I sanded the disc and put the sintered pads back on the front the squeal was less like normal but the warble was still there but not as loud.



I bought a normal shimano disc and it was a bit warped out of the box. but it only squealed a little in the rain and it would go away. but it would warp randomly in harder braking but it would straighten out on its own. so I bought another magura disc that was the same as the one I have. it only had a light squeal once while raining and that's it.



so disc noise may just be the disc if you have tried everything else. that includes cleaning and sanding the disc and pad realigning the calipers.
I had a similar experience. Tired everything, nothing really helped for more than a few miles. Changing out the rotor fixed it.
 

John Fuller

New Member
I have a SuperDelite with Magura brakes front and rear. I've put almost 8,000 miles on the bike, but the brake pads look OK. It seems like the pads should have required replacement by now, but I can't see or feel any degradation of breaking power. almost all riding is on paved surfaces with little requirement for braking. What's the general thinking on pad replacement? What mileage should one expect under the riding conditions I've described?
 

fooferdoggie

Well-Known Member
I have a SuperDelite with Magura brakes front and rear. I've put almost 8,000 miles on the bike, but the brake pads look OK. It seems like the pads should have required replacement by now, but I can't see or feel any degradation of breaking power. almost all riding is on paved surfaces with little requirement for braking. What's the general thinking on pad replacement? What mileage should one expect under the riding conditions I've described?
if your not braking a lot or going downhill a lot that will be fine. I mean if your stopping they are still working (G) they will start making a grinding noise when they need replaced.
 

Deacon Blues

Well-Known Member
I'm not sure what you mean when you say, "The brake pads look OK." The general rule of thumb is you replace your pads when they get down to 1.5mm.
 

fooferdoggie

Well-Known Member
I'm not sure what you mean when you say, "The brake pads look OK." The general rule of thumb is you replace your pads when they get down to 1.5mm.
yes with the magura they will have a bit of metal in the middle of the pad that will rub on the disc when they need changed. so if you have not hit that your ok. you can measure too of course but they do have a audible wear indicator in them. at least the last set I had did.
 

indianajo

Well-Known Member
I look at my brake pads when the handles get down close to the bar. Then adjust in if grey stuff looks thick, or replace if grey stuff looks thin. It's thin when the metal plate is thicker. that is much less than 1.5 mm. I don't believe the new pads were even thicker than 1.25 mm. I replaced one set at 4000 miles, the other not yet @ 8000 miles.
I was told on cars to avoid squeaking on disk brakes, put swirl pattern on rotor with a tool in a drill. These swirl tools are about $50 so at home I started sanding rotors radially with a 120 grit belt. Works on both cars & bicycles. However caliper should be adjusted to where pad doesn't touch on either side. Not sure if you are allowed to do that or even see that on hydraulic brakes.
 

Alaskan

Well-Known Member
Given the increasing difficulty of of obtaining most bike parts in a reliably timely fashion due to falling global production, delayed shipping and steeply rising demand. I have ordered and stockpiled (some would use the word hoarded) the following items, well before needed: two sets of brake pads for both front and rear for each of my bikes as well as replacement rotors, cassettes, three replacement chains, a set of tires and two sets of tubes per bike.

I think it is best to buy them sooner when it is not a problem for you to wait for shipping delays and your bike is working well and safe to ride. If they take way longer to get shipped, no stress. I would not want to wait until they are needed and your bike is unsafe or impossible to ride while you are waiting.

Plus it is not unreasonable think with the above factors, bike parts may be getting more expensive in the not too distant future.

About $300 dollars worth of wear parts that you will definitely need at some point in the future, if you ride much at all and may either cost you more when needed, take way longer to get in hand, or both, seems like money wisely spent...IMO.
 
Last edited:

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
Having a son in the business helps, too. Bikes are impossible, parts are getting hard to get as well. 😎
 

Deacon Blues

Well-Known Member
I just ordered a new chain and next I'm going to try a source a new 11-42 Shimano cassette.
The lack of Shimano parts is getting ridiculous. :mad:
 

Gordon71

Well-Known Member
I replaced my pads before my first spring ride. During break in I had some brake squeal from the rear brake. That night I cleaned the rotors with 91% alcohol which stopped the squeal.
 

Alaskan

Well-Known Member
The best way to avoid brake squeal on new brake pads it to do a proper break in procedure. Avoid normal smooth and easy braking until you do this. Take the bike the top of a good steep hill without having to brake to get there. Take it there on a rack if you can't get there without braking. Head down the hill and get the bike up to about 20 mph. Brake as hard as you can without going into a skid. Repeat 5 or six times. You should be good to go. If you still notice some squealing, do it a few more times ASAP.
 

Alaskan

Well-Known Member
I just ordered a new chain and next I'm going to try a source a new 11-42 Shimano cassette.
The lack of Shimano parts is getting ridiculous. :mad:
I have a Shimano SLX Hyperglide 7000 cassette with the following teeth, the largest of which is aluminum: 11-13-15-17-19-21-24-28-32-37-42

This is the cassette I pulled off my new Topstone Neo Carbon Lefty 3 at about 300 miles, when I replaced it with the 11-46 tooth cassette. It has been well cleaned in my parts cleaning cabinet and shows very little wear. Please sent me a private message if you are interested. Any suggestions as to the best shipper to use getting it from Bellingham over the Van Isle>
 

Deacon Blues

Well-Known Member
I've pm'd you.
Have you seen the new (and much cheaper) Sram Eagle AXS wireless shifter? Looks to be very nice and the price looks decent.
Have you noticed that Sram parts are usually available, but many Shimano parts are on back order?
 

fooferdoggie

Well-Known Member
brake noise can depend on a lot. kuje on my bike with magura rotors and calipers when I tried metallic pads the front was horrible with a horrible warbling sound once it got wet and even sanding pads and disc didn't to get rid of it. I ended up replacing the rotor. the nI got xt 4 piston calipers they came with metallic pads. but no bad noise on those rotors and if anything they are even quieter in the rain. so many factors in brake noise.
 

Alaskan

Well-Known Member
I've pm'd you.
Have you seen the new (and much cheaper) Sram Eagle AXS wireless shifter? Looks to be very nice and the price looks decent.
Have you noticed that Sram parts are usually available, but many Shimano parts are on back order?
I still have drop bars. Not sure the new shifter would have a good mounting location on drop bars. Any ideas?
 

Gordon71

Well-Known Member
The best way to avoid brake squeal on new brake pads it to do a proper break in procedure. Avoid normal smooth and easy braking until you do this. Take the bike the top of a good steep hill without having to brake to get there. Take it there on a rack if you can't get there without braking. Head down the hill and get the bike up to about 20 mph. Brake as hard as you can without going into a skid. Repeat 5 or six times. You should be good to go. If you still notice some squealing, do it a few more times ASAP.
That almost sounds like the exact opposite of what I read which was this:

After the pads are installed, get on the bike, pedal up to speed, and then gently grab the brake levers, slowly and smoothly applying pressure until you almost come to a stop. Do not stop quickly, but let the brakes drag you down to a slow walking speed. You want to heat the pads enough to lay down the transfer layer of pad material evenly across the rotor surface, and that's all.

Complete this slow stop process 10 to 20 times, and you're good to go. Braking too hard and thus generating too much heat will build up an uneven transfer layer, resulting in noisy brakes, wobbly-feeling rotors and underpowered braking. Coming to a complete stop will also lead to uneven pad material transfer, so this should be avoided as well.
 

fooferdoggie

Well-Known Member
That almost sounds like the exact opposite of what I read which was this:

After the pads are installed, get on the bike, pedal up to speed, and then gently grab the brake levers, slowly and smoothly applying pressure until you almost come to a stop. Do not stop quickly, but let the brakes drag you down to a slow walking speed. You want to heat the pads enough to lay down the transfer layer of pad material evenly across the rotor surface, and that's all.

Complete this slow stop process 10 to 20 times, and you're good to go. Braking too hard and thus generating too much heat will build up an uneven transfer layer, resulting in noisy brakes, wobbly-feeling rotors and underpowered braking. Coming to a complete stop will also lead to uneven pad material transfer, so this should be avoided as well.
yep its easier on a e bike and really easy if you have a 20% grade hill to do it on.