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Discussion Starter · #1 ·
Sorry if this is a repeat question. I've never logged into Brake Time before.

The front Sram G2 brake on my new SC Tallboy squeals when riding. If I tape the brake lever, the noise goes away for a very short time. I have no problem stopping.

Is the noise an indication that I need new pads? I had my shop replace the rear pads in the spring and don't have the same problem. I don't want to waste money if pad wear is not the issue.

Thanks.
 

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I have a set of G2s and love them, but a couple factors can make any disc brake make noise. I find that when my pads are glazed they squeal when they get wet. I live in a coastal area with lots of fog and marine layer. When my brakes heat up a bit, they attract moisture from the air which can make them squeal. This only seems to happen when the pads are glazed over, so I pull the pads and deglaze them with fine grit sandpaper and IPA-- Isopropyl alcohol. Lay the sandpaper flat, douse it with some IPA and then lightly scuff up the pad. I'll then take that piece of sandpaper and lightly run it over the rotor, Then dry everything with a clean piece of paper towel. While the pads are out, double check 1) that the pads have even wear. Sometimes a pebble or something will get caught in the brake and wear a grove through the pad. 2) that all of the pistons are equally exposed--sometimes uneven pistons can cause a noise. If you see uneven extension, clean the dust and push the pistons back in. Then reinstall everything, making sure the caliper is centered.

This procedure works most of the time, but brake noises can come from a variety of causes. Sintered pads make more noise than organic. Pads that get contaminated will make noise and generally require replacing. Pad contamination can come from a variety of sources. I kept having fouled pads and for the life of me couldn't figure out why--then, I saw my wife spraying on sunscreen next to my bike...smh... I also find that if the rotors have been burned up--discolored-- they are more prone to making noise.
 

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Discussion Starter · #4 ·
I have a set of G2s and love them, but a couple factors can make any disc brake make noise. I find that when my pads are glazed they squeal when they get wet. I live in a coastal area with lots of fog and marine layer. When my brakes heat up a bit, they attract moisture from the air which can make them squeal. This only seems to happen when the pads are glazed over, so I pull the pads and deglaze them with fine grit sandpaper and IPA-- Isopropyl alcohol. Lay the sandpaper flat, douse it with some IPA and then lightly scuff up the pad. I'll then take that piece of sandpaper and lightly run it over the rotor, Then dry everything with a clean piece of paper towel. While the pads are out, double check 1) that the pads have even wear. Sometimes a pebble or something will get caught in the brake and wear a grove through the pad. 2) that all of the pistons are equally exposed--sometimes uneven pistons can cause a noise. If you see uneven extension, clean the dust and push the pistons back in. Then reinstall everything, making sure the caliper is centered.

This procedure works most of the time, but brake noises can come from a variety of causes. Sintered pads make more noise than organic. Pads that get contaminated will make noise and generally require replacing. Pad contamination can come from a variety of sources. I kept having fouled pads and for the life of me couldn't figure out why--then, I saw my wife spraying on sunscreen next to my bike...smh... I also find that if the rotors have been burned up--discolored-- they are more prone to making noise.
Thanks for the info. I think its time to replace the pads. I'm a Northeast rider and moisture is a constant here too. The rotors look fine. I can take a closer look at the pistons when I replace the pads.
 

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Sorry if this is a repeat question. I've never logged into Brake Time before.

The front Sram G2 brake on my new SC Tallboy squeals when riding. If I tape the brake lever, the noise goes away for a very short time. I have no problem stopping.

Is the noise an indication that I need new pads? I had my shop replace the rear pads in the spring and don't have the same problem. I don't want to waste money if pad wear is not the issue.

Thanks.
So the noise starts when you are NOT applying the brakes? hen you tap the brakes the noise stops? If this is what is happening, then it's not a brake pad issue. mine do this on occasion as well. I think it's related to two things, you may need to bleed and/or need to clean the pistons. Cleaning has worked for me until they get dirty again.
 

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Mine do this on occasion. As long as the caliper is centered I can usually just push all of the pistons back and get everything balanced again and the noise goes away with even piston retraction. The pistons do get catawampus every now and then with things getting knocked about. Its a mountain bike after all.
 

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Discussion Starter · #7 ·
So the noise starts when you are NOT applying the brakes? hen you tap the brakes the noise stops? If this is what is happening, then it's not a brake pad issue. mine do this on occasion as well. I think it's related to two things, you may need to bleed and/or need to clean the pistons. Cleaning has worked for me until they get dirty again.
Correct, the noise starts when I am NOT apply the brakes and it stops when I tap them. I will have to look at the pistons and clean them but I do want to replace the pads anyway since they have a fair amount of mileage.

Thanks for the input.
 

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Discussion Starter · #8 ·
Mine do this on occasion. As long as the caliper is centered I can usually just push all of the pistons back and get everything balanced again and the noise goes away with even piston retraction. The pistons do get catawampus every now and then with things getting knocked about. Its a mountain bike after all.
Yes, it is a mountain bike and my areas are fairly rocky and rooty tossing the bike about.
 
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