Disc brake squeal/vibration

As long as you match pad material to the rotor’s the caliper can be used with just about any rotor. I don’t mean to make it sound like the pad compound is that particular, but certain rotors are not happy with the wrong compound. Rotor width is fairly standardized, and the self adjusting function of hydro calipers ensures that you will have the right clearance regardless of thickness. This is how they continue to have good lever travel even after pads, and rotors wear significantly.

The only thing that I’m aware of that would make a rotor incompatible with a caliper is if it’s an odd size that you can’t get a suitable adapter for. What I mean is that some brands make 200mm rotors, and others are 203mm or 205mm. All of these are essentially the same size, but depending on your caliper you may not be able to get a mount to mix brands that are slightly different. A lot of the time you can make up the difference with washers, but it can be a pain to get it right.

I don’t have one of these disc brakes and I haven’t seen one up close, but I have an idea. Maybe it would work or maybe it wouldn’t apply here. Get some disc brake quiet compound for automotive applications and apply it behind the pads where it would be applied on a car. Sometimes disc brakes just like to squeal or chatter and this stuff works.

I’ve actually had luck in the past (on a bike) putting masking tape on the back of the pads.

But in the end, on my unicycles I’ve found that they usually just need broken in. The first few rides you think they’ll be loud forever until they just seem to stop.

Thanks for the explanation Jtrops, that helps a lot. Much appreciated. :slight_smile:

Will order some organic pads first and if they also squeal like crazy will try replacing the rotor and see how it goes.

That would be great if the vibrations just disappear! You might have a point there.

This is what I was getting at with the comment about cleaning the pads, but leaving the rotors alone. It’s important to properly bed in the rotors, but glazed brake pads can be a problem. Sanding the glaze off of the pads, but leaving the rotors alone can work wonders.

My TRP Spyre squeaked for a while when new and I kinda liked it. It’s quietened down now. I then started noticing more vibration at super low speed maximum threshold braking- think a 36"er going down a 10%+ grade at 3-4 mph. No biggie overall and I’m gaining confidence going down steep declines at (slightly) higher speeds. This has helped with my shudder.

Anyways- my thought on the vibration issue is… There’s some crazy (and a few bad ass dangerous) rotor designs with all kinds of cut outs in the area where the pads contact. Maybe certain designs and spacing of the holes on some rotors are more prone to resonance as we one wheelers use them. Most disc/rotor combos were designed (or at least tested) on bike applications.

Maybe try a different rotor design.

Also,could air in a hydraulic brake system as the OP has cause a modulation problem? Maybe a check of fluid level and a bleed might help.

Rotor design can certainly contribute to the problem. I don’t think bleeding the brake will help at all. A bad bleed, or air in the line, will cause the brake to feel soft and spongy.

to eliminate vibration of the d’brake, you could try Hugos solution. With this setup he successfully eliminated any noise and vibration.

Got it now. :smiley: Didn’t realise does what you meant.

Will keep that in mind. Thanks again :slight_smile:

That is really nice! I think we miss a lot be not being able to understand what’s being posted in the other language forums. I wonder if someone who speaks German and English could translate his write-up? :slight_smile: That would be very cool! (I don’t run a disc brake, but I like seeing things that are imaginative and that work well.)

Ok, I’ll try:

That’s great, thanks a lot, Eric.

That’s a really cool device. I was thinking about a disc brake based on what I know from bikes, and I forgot about the Dbrake. I’m sure that is the reason the vibrations are so bad on the uni It probably just hums on that boom mount. The brace up to the maggie mount is a great solution.

I have had the Oracle 36 for a year and a half. When applying the brakes on a downhill the whole uni resonates. I was told by Josh from UDC that it just needed breaking in, but it still does it after a year and a half.

Yup, and some need more work than others, it can be a variety of issues from pad design to rotor design, even harmonics.

After having tried all the easy fixes, now it’s time to try changing one thing at a time, in the order of least cost:


Organic pads do seem to help, but semi-metallic work the best when hot, so if you’re having glazing you might want to see if there is an all metal pad.

My favorite cheap rotor is the Avid that comes stock with BB7 brakes.
My favorite expensive rotor is the Hope Floater

In terms of calipers, the one you have is the cheapest you can get, I gave mine away for the same reasons you are describing. A good Shimano caliper like the M575 or similar is all you need.

Yes it does a bit, but for sure the little D part holding the brake must have problem resisting the forces it takes when you brake. The reinforcement part seems to be the right answer.

Thanks a million for your advice Nurse Ben. It helps a lot. Makes sense to follow these steps in that order untill I get a happy combo. When I was trawling the forum for a solution to this problem I’ve noticed you have tried many brakes in the past so I know how valuable is your advice on this matter :slight_smile:

Also note this solution if you don’t have a KH frame.

I gave Hugo’s method a try. It works pretty well - still some high pitched squeaking, but most of the vibration is gone. Made a previously unusable brake (due to vibration) useful again. Worth doing for sure.

Hi there

I forgot to update my brake/pad situation (have been away from the forum for a few months!). For all of you that were also having problems with the same brake/pad combo as mine: as advised on this forum I kept the original calliper and rotor but changed the braking pad (Clarks Organic Disc Brake Pad for Tektro Volans/Auriga Twin/Auriga Sub/Auriga E-Sub Bikes).

Glad to say that the brake has been working fine since I fitted this organic pad quite a few months ago. I might get the odd hum here and there but, thankfully, no vibrations. Very smooth breaking. So I’m really happy with it. It works way much better than the original pad that came with the Oracle 36 unicycle (the tektro) and the other pad I tried afterwards (jagwire). Another plus: the clarks Organic pad is way cheaper than the Tektro or the jagwire.

Where I live is very hilly and as far as I can tell this pad works well (no problems with breaking in very steep hills).

Hope this helps to someone and thanks again to all of you that helped me along the way :slight_smile: