Dean V

I have a Domane SL6 disc which I am very pleased with except for the noisy brakes.
They are Shimano hydraulic with the 685 levers, flat mount callipers.
There are no problems in the dry but in the wet they squeal when used and I also get a lot of rub noise, also only when wet.
Any ideas?

Cyclist0108

I have no idea why it would do this only when wet, but it suggests they could benefit from some micro-adjustment. What I have found to be the most effective way to do it is this:

(1) Take the pads out. Also make very sure at this point that the wheel is properly seated in the dropouts (or thru-axle hole) and tightened down well.

(2) Sight where the disc is relative to the caliper. If it isn't very close to being centered with respect to the slots in the caliper, you are doomed, so that is the first adjustment to do.

(3) Put the pads back in and test it. That may be enough.

(4) If not, push the pistons back into the caliper. (You have to take the wheel off to do this.)

(5) Repeat step 3.

(6) If you still have no joy, loosen the mounting bolts again, and very incrementally move the caliper + pads until you hear no rub, and tighten it back down, and keep checking as you do this.


By the way, do you like the bike? I'm starting to think about it for an N+1.

ne_dan

What type of pads organic or sintered?

It's probably just the moisture burning off the brakes when they are wet and the rubbing is just road grim kicked up from riding in the wet.

Dean V

The pads are the stock ones. Don't know what variety they are.
Road grime is a possibility. I know the pads don't retract much which is great for brake feel and minimal lever travel but the pad to disc clearance must be very small.
The bike rides great but it does seem to be slightly down on speed to my usual road bike. I am guessing it must be the tyres (32mm Bontrager).
It is no lightweight either at around 8.5kg ready to ride. But that is ok as it isn't for racing just a do it all training bike.

FlashBazbo

Disc brakes often (not always) squeal when wet. On mine, the rear does but not the front, and only when wet. I would assume this is because the rear brake also catches some road grime with the water.

If there's no noise and no rubbing when dry, leave them alone. They are good.

alcjphil

So, a disc brake bike weighing 8,5 kg with 32 mm tires is "heavy"? Or, was I dreaming when I read this?

Cyclist0108

That sounds about right. The US website says it is about 18.5 lbs.

That is quite light compared to my steel bike with a Brooks saddle, rear rack, etc. and one of the reasons why I want to try it. I'd like to see if the steel frame is a significant penalty. (At 195 lbs, I have always scoffed at this idea.)

The pads that come with those brakes are the organic ones, btw.

Silvercivic27

My solution is rim brakes on aluminum rims with no goofy coatings or machining.

DrIsotope

Some people reject reality in favor of one of their own design.

You heard it here first, folks-- 18.5lbs is heavy. Maybe it's like a 52cm frame-- my wife's bike is tiny compared to mine, and weighs about 18lbs sans water bottles. She'll be disappointed to find out it's now heavy.

GeneO 

Hey, that is what my disc gravel bike weighs. I'm offended. LOL.

DrIsotope

I did a charity ride this past Saturday, and would be lying if I said I wasn't tickled when the guy on the Pinarello Dogma F8 with super-deep carbon wheels rolled into the finish area about 20 minutes after I had on my 24lb steel CX bike... with 1x11. All I need is one gear per kilo.

Chandne

I'd say leave them alone too. If you must fiddle with it, do what I did once but my cross bike was squealing right after the build. I figured the mechanic had gotten oil on the pads. I took the pads out, soaked them in 91% alcohol, and lit them on fire. The flame quickly burns off, along with any contaminants. Just don't touch them for 5 mins after the fallen goes out. This is a MTB trick. Anyway, it hasn't made a sound since.

Since it is happening ONLY when wet, I'd leave them alone. That is somewhat common.

GeneO 

Yeah, sometimes mine wail when wet. But they work good when wet.

Dean V

No problem at all with how the brakes work, wet or dry.
Just the noise is a bit annoying. I like my bike to be quiet.

WhyFi

Mine sounded like a car horn (each disc sounding a different note) the last time I was out in a solid rain.

DrIsotope

I love the angry goose honk my brakes make in the rain. It alerts cars (and everyone else within a hundred feet) to my presence. It's definitely the road grit/grime and not just the water-- the honking is much more pronounced on freshly wetted roads. If the rain is coming down at a good rate, or there's standing water, the brakes go back to being silent again.

This is with organic pads.

daviddavieboy

I wonder if this is achieving a similar result to pre scorching pads on a car.

dfweisjlsk

What kind of brake pads are you guys using? If the noise really bothers you, I'd suggest trying ceramic pads. They're not as good as sintered pads at stopping though.

Chandne

Probably so, and I have only done it twice. Coincidentally, both times were after a mechanic built up the bike or bled the brakes on the MTB. Both times worked so well. They also say to not clean the discs with alcohol...just leave them along. A little water will not create any problems but totally cleaning the discs...that can make them squeal again till pad material is deposited during hard braking.