Brake rotor noise and vibration

Tech Tech Help
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Hi escapees/escapists (?),

after 5 years on a rim brake bike I made the switch to a Tarmac SL8 with 105 groupset. Not a fan of the stamped 105 rotors so I got the shop I bought it from to set it up with nicer ones, they recommended the Galfer Road Shark in 160mm.

I’m on the heavier side (93kg, not fat, just lifting weights) and I live in the alps so long climbs and descents are the norm.

Now I got some screaming noise and vibration in the bars/bike while braking on the descent that I can’t get rid of at all.

First cleaned the rotors and pads with brake cleaner, sanded down the pads, bed them in again. Same problem. Bike shop fixed me up with some SwissStop pads free of charge, bed them in for me (they have the fancy bedding machine), tried again. Still there. Changed the rotors to SwissStop as well to get more thermal mass and braking surface in there, one pad was still fine, one was a bit glassed which got changed as well. Got bedded in again.

Different sound this time, probably due to the different rotors but the problem persists.

It is only on the front brake, it happens when I start to brake and stops when I either stop braking or pull the brake in further, but I cant brake like this every time. Headset is tight, front axle is tight, centerlock ring is tight.

I’m not new to road or mountain biking, I wrench everything on my mountain bike myself except for suspension service, the brakes on my mountain bike are completely fine even on long and steep descents (sram maven). Went to Mallorca last year on a rental with stock Ultegra brakes and had no problems anywhere. I have zero doubt that the shop does professional work and knows how to both install a brake and bed it in.

Kind of at a loss right now and would be thankful for any insights or solutions that I haven’t tried. Is it the brake, the rotor, the pads or something else on the bike? Is it my braking technique?

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I doubt it’s your weight or technique. It’s likely down to some combination if the components causing the issue. You’ll probably eventually get to a fix by swapping parts. With that in mind, if it was my bike, I’d next swap out to Ultegra ICE rotors and pads . If that’s not a solution, try an Ultegra caliper. And so on. Since the bike is new, hopefully the dealer will help defray the costs.

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I had some similar issues on a mountain bike (glazing pads), which was resolved by upgrading rotor sizes to alleviated my heat issues. Pad material type is also not mentioned, but sintered pads are a lot more heat resistant (at the expense of cold/wet noise and rotor wear)

Given you are already on 160 rotors I know Peak Torque makes 180 rotor adapters for road bikes also but not manufacturer approved (link 180mm Disc Rotor Adapter for flat mount road/gravel forks – PEAKTORQUE )

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Facing the flat mounts with a professional facing tool is usually the final remedy for brake connected nuisance.

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Funnily enough, I tried that Peak Torque 180mm adapter and suffered all kinds of noises until I reverted back to 160mm. Of course, I might have failed to bed-in the 180mm rotor properly. Who knows? (I weigh close to 100kg)

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Sometimes discs are just noisy for no obvious reason. Several years ago I had DA9100 levers, calipers, and rotors and they were silent when dry, but squealed like banshees if it was wet; I was very surprised the first time it rained. The problem was “solved” by bike thieves in the UK.

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I had a similar front brake vibration/squeal problem on my Aethos. Everything set up perfectly. Tried different wheels, different rotors, different pads. Nothing seemed to work. So for a while I lived with crappy front brakes. Then out of the blue, I wanted to try a different riding position, added 20 mm (length) to my stem, and the problem went away completely.

Maybe you just got “lucky” and your weight distribution paired with the stiffness of the fork happen to allow it to hit resonant frequency.

I’m relatively light for my height (56~58 kg 172 cm; 125 lbs 5’8”) - possibly too light to weight the front fork properly.

I recall a podcast between James Huang and a Hayes engineer where the engineer advised Scott to make their chainstay heavier which resolved some resonance and brake squeal issue. Perhaps you can try:

  • sliding way back off the saddle while braking to test if weight distribution is a factor
  • sticking some lead tape to the fork to see if it makes any difference.
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The vibrations in the Galfer rotors may be from variations in thickness (beyond an acceptable tolerance) where you physically feel the undulations of the hydraulic system reacting to the differences in rotor thickness. I’ve had this happen on a SRAM Centerline X rotor before, and have warrantied one successfully based on that issue.

The horrid brake sounds are likely coming from micro-leaks at the caliper. I’ve had it happen on my rear brake of my cx bike, a well-used set of Saint calipers formerly used on my mtb, as well as brakes of friends. I’ve gone through the cycle of replacing pads/rotors, bedding them in, brakes working for a bit, and then horrible howling during braking after the small period of quiet braking. I would warranty the front caliper through a reputable shop with a Shimano account, and provide them documentation of purchasing new pads/rotors in an attempt to resolve this issue.

This weird, annoying defect in Shimano brakes makes me really hesitant personally to buy any used Shimano calipers, as I am not really able to warranty the used caliper if the issue is present.

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Thanks for the insights so far everyone. At first I thought it was down to rotor and pads as well, but it happened over 3 different combinations of those which led me to assume that it came from somewhere else.

It does look like the front rotor is getting a bit hotter than the rear, rear has the bronze color while the front is more purple but not in the scorched part of the chart yet.

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I don’t feel like I brake disproportionately much with the front, descending it definitely feels like there’s more weight over the front than on my old bike and I’m not super confident cornering on the drops yet but that is to be expected from the lower riding position compared to the previous bike. Shifting the braking more towards the rear would just lock up the wheel.

My next step would be trying the Dura Ace rotor with finned pads at the front to get one other combination of materials and to see if I can get the system to run a bit cooler. If that doesn’t work the shop said facing the brake mounts is possible but they never had any problems with the tolerances on the Tarmac before. If still nothing helps I’m gonna try the more out there options like stick-on wheel weights at the fork.

Edit: after some forum rabbitholing I did find a few threads that described that same exact problem (vibration and noise with no discernible loss in brake power and properly set up brakes). I’m going riding today with some weights stuck to my fork I guess.

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The vibration and noise can also be attributed to the weird radial DS lacing and 2x NDS lacing Spesh does on most of the stock groad bike front wheels. Ask a friend if you can borrow a normally laced 2x or 3x laced TA12X100 front wheel, and you will like notice a significant difference in brake feel/vibration/noise.

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If heat is an issue, you can also try Formula monolithic rotors. They are slightly thicker (1.9mm for 160mm diameter rotor) and have fewer and less aggressive cutouts. The design of the cutouts also make the brakes less grabby. These changes (thicker, heavier and stiffer rotor + reduced static friction) might be enough to change the resonant frequency for you.

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Did a short and steep descent with an 8mm Allen key taped to the brake side of the fork. Could still make it squeal with prolonged braking. Might have to test it on a longer descent both with and without on the same ride though

Also tried braking more with the rear wheel which made the front silent but then the rear got noisy, with less vibration though. When just pulsing the brakes it’s mostly fine except when cornering.

I have a dura ace rotor and finned pads coming in the mail, let’s see if those help.

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Some ideas

  • Don’t clean the rotors too much, or at all. There’s the risk of contamination, as well as removing the layer of material deposited by the brake pads
  • Vibration can be caused by the pad material on the rotors being uneven. Possible reasons for that are: loose headset, braking hard while coming to a full stop, braking hard in general. Gently dragging the brakes can fix this to a degree
  • Is the caliper is centered/aligned well enough? Do both pads contact the rotor at the same time? Is the rotor straight?