pbass

Is it possible that there are some bikes, due to construction and components, that are simply prone to noise coming from the front fork during some braking efforts? For example, let's say everything "checks out" --pads, rotors, everything nice and aligned and tight, bedded in, etc etc--all the typical steps have been taking to eliminate any noise from the brakes. Rear brake is silent. However, you get an intermittent howl from the front end when braking, but the noise only seems to happen when first applying them after they've had a chance to cool down, like on a climb, then followed by a descent where you brake. But the noise only happens on that first braking effort on the descent, not if you let up and re-apply. And, the noise only happens intermittently in the braking effort, roughly halfway between no braking power, and almost locking 'er up. And sometimes, it doesn't happen at all. This is my scenario with my gravel bike. It really seems like there's a vibration thing going on. I'm wondering if it's just that this bike, with me (at my weight) on it, are experiencing some vibration phenomenon under certain conditions when braking that's creating this noise. This is a steel bike with a steel fork, btw. Are there some bikes out there that (short of actually trying a different fork) in concert with the rider at a given weight, are just gonna make some front end braking noise at times no matter what?

fietsbob

BB7... my 2nd pad set, Kool Stop Organic Resin compound, was Quieter than Avid Stock...

Will be trying another resin compound pad on the HyRd caliper, I put on instead.

I don't ride fast or brake hard. discs on Rain bike..

Stock TRP pad on front only makes noise when its wet out.. back never has..

dsbrantjr

Yes, it happens often.Vibration-type issues can often be skirted by changing simple components like brake pad or rotor brand/model. Do the cheap and easy things first. Easiest and cheapest might be to ignore the noise if the brakes are otherwise satisfactory.

pbass

Thank you--this is where I'm at I think! Unless it gets worse.....

Bigbus

I have the exact same problem on my MTB. I replaced the rotor first to no avail and then switched to resin pad, to no avail. Then I took the components off another bike that didn't make any noise and now they do on the MTB. I have come to the conclusion that the vibration stems from the Suntour suspension fork on the MTB. When I really slow down I can see and feel it vibrate and I think that is the core of the noise problem. My 2 cents worth.

Delmarva

Glazing on the pads and rotor can cause brake noise.

Rick

Misaligned caliper can also cause noise.

pbass

Yep, have checked alignment, pads, rotors, the works. Have NOT tried different pads/rotor yet. I guess I can go down that route. To make it even more head-scratching is that as I say, sometimes it's totally quiet. Other times, like today, not so much. And as soon as I think I see a pattern developing, based on whatever factors - speed, degree of descent, heck even the weather - it goes and breaks the pattern. The only consistent thing about it is it's inconsistency!

pbass

Well, to update...even though as far as I could tell, my caliper was aligned, I yet again loosened it up and re-tightened, double-checked alignment--rotor not bending/pulling at all when brakes applied, etc----and voila! I seem to have greatly reduced the noise, like by 90%. We will see. I guess there's a very teeny sweet spot in there....

u235

What material or pads are you using? Resin/organic are usually the quieter of the types, metallic/sintered louder and mixed semi pads some where in between. Different makers of pads have different ratios of resin vs metal and different sizes of metal particles and may end up being more like resin or metallic depending. I've had repeatable noise a few times (even when not wet) and like mentioned above, usually deglazing the pad and cleaning the rotor fixes it. You may have some combination causing some resonance, maybe try a different pad made by someone else with a slightly different composition and see if that helps or maybe something simple like swapping pads between front and back and see what happens.

pbass

These are the stock pads that came with the TRP Spyre C's on my 2019 Kona Rove ST, described as "ultra-grippy semi-metallic pads". Haven't thought of swapping the rear pads from the nice and quiet rear end, to the front just to see what happens. I'd have to re-bed everything though, correct? I hesitate to mess with the rear since it's so quiet now! Right now, the front is tolerable, so I'll see how it goes. Will look at trying different pads when I replace these.

Gresp15C

I'm just following the thread with interest. A new bike in the family fleet has a front disc brake that howls so loud you can hear it down the block. I've tried to diagnose it, and the thing I've noticed is that the howling pitch is very close to the pitch that I get when plucking the spokes. I was able to calm it by wrapping an old innertube between the disc and spokes, but that's hardly an elegant solution. The shop tried a different brand of disc with no improvement. It's detracting from enjoyment of the bike.

base2 

It can just be a resonnance between the brake & the spokes. I had a bike that only did it when it was wet out. Cleaning things actually made it worse. The road bike had an Avid BB7 with a 180mm stainless rotor on a 20 spoke road wheel & a carbon fork that resonated like a guitar body. Gawd it sounded awful, but worked great. The BB7 caliper & pads got moved to a bike with a 32 spokes of lesses tension on a 26 inch mountain bike wheel, 180mm IceTech rotor with a different spider design & suspension fork. The result was absolute silence.

You might just shuffle things around in your stable a bit, just to see where you end up. FWIW: the lesson I learned was: Fewer spokes under higher tension are more likely to resonate like a guitar string. It is totally usual for disc brakes to squeal like a mouse sometimes though. With my situation, you could hear me comin' all the way down the block & that is what I assume you are talking about. Swapping parts will change the resonance.

Geekage

I was suggesting you swap both the pads and the rotors (if they're the same size. Yeah, you'll have to unbolt them), so they'd be the ones that had already been bedded together.

But I guess you already tried bedding the brakes already, so that might not be the issue.

pbass

I used to religiously clean the rotors on my mountain bike with alcohol, even after rides that weren't THAT dirty. On that bike (with BB7s) it made all the difference in the world as far as noise. On this gravel bike (with Spyre Cs), I'm starting to think it makes it worse to clean it as you say!

Bigbus

An update: I thought I'd tried everything including new rotors, new disks from a lbs, and even swapping with a set of disks and rotors from another bike that didn't screech when applying the brakes. Well today, I no longer have the problem. For a buck and a quarter American dollars, I ordered a set of resin pads from the bay. They finally arrived and I installed them, wiped the rotor off with a clean cloth and suddenly I have great braking power with no noise. In fact, they are quieter than the rears which I always thought were almost silent, just a slight noise. I took it up a hill with 7% grade and then flew down working the front brake. Another few times around the block and still no noise. NONE! It's great. Now I need to find me a good horn or bell to mount on the handlebars. Life is funny that way...

base2 

AWESOME!