Cube shimano disc brake sounds like an HGV

jpower

Firstly apologies I did not search, not well and looking for the easy way out.

New bike cube agree disc done around 300km, first ride was fine, rides since the brakes make so much noise they stop perfectly but I'm scaring fellow bikers, I can play the dukes of hazard horn.

Advice please on how to make them stealth please.

keef66

Never had a bike with discs, but on the cars screeching disc brakes are usually sorted by applying copperslip or similar to the backs of the pads.

I've also read about discs needing bedding in before they become fully effective. Few trips down a suitably steep hill with some aggressive braking at the bottom?

cooldad

Don't try copperslip or anything else on bike brakes. Cars are quite different and reach much higher temps. More likely to contaminate the pads if nothing else.

Rinse with a bit of clean water, and ride. MTBers will tell you that discs can be noisy, it seems to come and go, often a bit of sloshy mud sorts it out.

Have you made sure you have pads left - metal on metal can be nasty.

jpower

I've not checked but after 300km sounds harsh to be gone, so just clean with water then?

Steve-XcT

jpower wrote:

I've not checked but after 300km sounds harsh to be gone, so just clean with water then?

You can use isopropyl if you have any.... but water works fine but (after checking the pads) make sure you wear them in and wash and wear and wash.

It's not clear what they changed... was it the rotor or pads or calliper???

If the rotor is new but not the pads then they may have cut a groove etc.

jpower

It's a brand new bike so all original as bought

Steve-XcT

jpower wrote:

It's a brand new bike so all original as bought

New bike cube agree disc done around 300km, first ride was fine, rides since the brakes make so much noise

So you haven't changed pads or rotors? If you're new to disc brakes you probably didn't bed them in... this usually doesn't affect stopping but you can end up with noise like a flock of geese following you.

They may not be aligned properly and worn the pads unevenly ... its pretty common... I have adjust callipers when I change wheels and that with through axles....

Take the pads out and have a look how they have worn.... if they aren't worn evenly then stick new pads in and re-bed with water and some friction... also check the rotor is firmly fitted and not buckled at all. I tend to knock mine more putting wheels in the car etc. than on the bike (you can take one off and stick it on a flat glass surface and not find the buckle)... but stick it in and you'll hear it on the pads.


edit:
Oh you could also have got oil on the pads/rotors.... it does decrease performance but if you are used to non discs then you would probably still think they were darned effective.

If you have been using a spray on the beautiful new bike or even just touching with your fingers....
Pads + oil = right off
Rotor + oil = isopropyl alcohol/bike specific brake cleaner then rebed.

jpower

what is this bedding in process?

bbrap

jpower wrote:

what is this bedding in process?

Get up to 20 ish mph, put brakes on hard until almost at a standstill, accelerate up to 20 again and repeat 10 times. I find that doing the front and back separately (so 20 times in all) works best as its easier to control.

jpower

Interval training

Steve-XcT

bbrap wrote:

jpower wrote:

what is this bedding in process?

Get up to 20 ish mph, put brakes on hard until almost at a standstill, accelerate up to 20 again and repeat 10 times. I find that doing the front and back separately (so 20 times in all) works best as its easier to control.

Works even better with a water bottle full of water.... and squirt some on each time.

jpower

Just ordered some of those alcohol wipes figure be good to use those after each ride.

bbrap

jpower wrote:

Just ordered some of those alcohol wipes figure be good to use those after each ride.

I find a bottle of IPA (Iso Propyl Alcohol) on a paper tissue works just as well (and is a lot cheaper than the individually packaged wipes). I just fold a tissue into a small square and put over opened top of bottle, tilt bottle to moisten tissue and hey presto alcohol wipes.

jpower

Was £1.99 for 100 wipes so will see how far that goes.

bbrap

jpower wrote:

Was £1.99 for 100 wipes so will see how far that goes.

Can't argue with that. One word of caution, don't buy masses of them in one go. I had a packet of wipes in the glovebox of a car, must have been there for a couple of years. When I came to use one they had dried out and were crinkley rather than moist even though the packaging was unopened and each individually sealed. Same thing happened with lens wipes (I wear glasses), bought a load thinking the bulk buy was good value.

lettingthedaysgoby

I've got a Cube Attain with discs. They've been totally silent for the entire year I've owned the bike and I've never done anything to them cleaning wise... until the other day when they made the same horrible noise you describe.

However, I was riding in possibly the worst conditions I've ever been out in - rain, mud, some remaining snow/slush and all the other usual road muck from this time of year.

Lightly dragging the brakes would stop the noise for a while, then it would come back. So I assume it was just a build of of censored on the rotors that was then being burned off. At no point was braking performance affected, they were still as good as ever, just somewhat noisy.

I'll see if they do it again when I'm next out and report back...

jpower

Thanks be good to hear back. Next outing tomorrow so let’s see what happens, as I don’t have the wipes yet will be just water clean and see if that helps.

jpower

bbrap wrote:

jpower wrote:

Was £1.99 for 100 wipes so will see how far that goes.

Can't argue with that. One word of caution, don't buy masses of them in one go. I had a packet of wipes in the glovebox of a car, must have been there for a couple of years. When I came to use one they had dried out and were crinkley rather than moist even though the packaging was unopened and each individually sealed. Same thing happened with lens wipes (I wear glasses), bought a load thinking the bulk buy was good value.

Good point made some bulk errors like that myself.