Sqeaking brakes

[Tarka]

Moving on from the rights and wrongs of rotor rotation, lets just have a think about brake noise. I say noise rather then squeeling or juddering or scraping or any manner of unwanted acoustic nuisance.

Any friction is an energy transference. When we apply braking force, the energy we wish to remove in order to slow down has to be changed into another form of energy (Newtons Apple tree or something like that).

In an ideal world, that energy would become heat, dissipated via the friction material to both the rotor, the calipers and thence to the air.

In reality of course there is also acoustic energy. If a frequency oscillation occours, a sound will be generated, if that oscillation is excessive then the noise can be most unwelcome.

To conclude, if your brakes sqeel horribly, then your brakes are broken

 

[soundwave]

my m8 uses wd40 to stop his from squeaking and sprays it in to the caliper on to the brake pads

it does work for a bit tho pmsl

 

[Andy-Mat]

my m8 uses wd40 to stop his from squeaking and sprays it in to the caliper on to the brake pads

it does work for a bit tho pmsl

But it must reduce the efficiency of the brake(s), as WD40 is a penetrating lubricant.....
I use it for many things, but not on brakes....
Andy

 

[soundwave]

But it must reduce the efficiency of the brake(s), as WD40 is a penetrating lubricant.....
I use it for many things, but not on brakes....
Andy

he wont listen n look what happens pmsl

 

[EddiePJ]

Well, having been thoroughly derailed, lets get back to the squeaking.
My problem was that I would set the brakes up just fine, but in no time they would start squeaking, not when braking but just going along.
I changed the front rotor which cured it, but feeling reluctant to going to all the bother of changing the rear one, I squirted it with citrus degreaser, gently applied the brake and rolled the bike forward to distribute the cleaner onto the pads, then used a strong hose pipe to thoroughly wash the disc and pads etc.
Seems to have worked, so I can only surmise that the problem was a build up of brake dust.
Andy-Mat need not reply!!

Mike, sorry that what should have been such a simple to sort out problem, has been so greatly extended into a white noise debate. I switched off within the space of the first page, so what is said below might have already been stated.

Nealh has summed things up pretty well when talking about pad material, and compatibly of rotor material. Here is a short basic guide.

Brake Pads - A break down of what you need to know - Pinkbike

There are a lot of people who know a lot about bikes, how to set them up, which components are better, and especially how to ride them. I also know that there are many often overlooked parts on a bike, one of them being brake pads. Now I know what you are thinking, "A brake pad is a brake pad...

www.pinkbike.com

You appear to have the issue sorted now, and my assumption of the issue would have been either material incompatibility, or pad contamination which is more likely. Cleaning and degreasing pads doesn't really work too well in the long term, and really the best option given the price of them, is to replace with new pads, ensuring that the rotors are spotlessly clean before fitting.

 

[soundwave]

it will also help if you give the rotors a rub down with some fine sand paper if there new as gives them more bite and will bed in faster and then a rub down with some cleaning fluid.

i got some brake pads here that just dont work with my rotors very well they dont make any noise but the feel is like braking with grit till they heat up and then there fine so more for a day at the fod than blasting round the roads and paths ect.

 

[Deleted member 25121]

And another point, of course, is that if your brakes make a noise (only) when they're not being used then a pad is rubbing the disc and this will slow you down.

 

[RossG]

What do you mean by "the dynamic" ?? Young's modulus is applicable to both stationary and rotating objects, and we're talking about the stresses in the spokes not the disc anyway.

Maybe we should assume manufacturers create disks with arching spokes, and then advise they are fitted pointing towards the direction of travel because they look nicer that way.

Looks like mike's solved the problem now luckily so job done.

 

[soundwave]

i bet not one of you have cleaned and lubed the caliper pistons no point just pushing it back with new pads as it will just get stuck again rub on the rotor and make a noise.

every 6 months you should clean and lube the pistons so there moving about the same so to center the pads on the rotor otherwise if one is moving way more than the other it will make 1 pad way closer to the rotor than the other and be a pita to center the pads on the rotor.

it might not make a noise but it will wear down the pads way faster.

use the brake fluid your bike uses to lube the pistons with a q tip or use the hope stuff just dont pop out the pistons or you will need to bleed the brakes and rebuild the calipers

 

[Andy-Mat]

Its sad that apparently so few people here are open to a new idea, and condemn it out of hand, without actually trying it....
I believe tat the problem brakes have been made wrongly, spokes wrong made....too thin or wrong material possibly.
We need a fe here with the problem, willing to swap the disk around.
Plus we could do with a few more qualified engineers here.
I am not really surprised though, seen it before!
regards to all
Andy

 

[soundwave]

Its sad that apparently so few people here are open to a new idea, and condemn it out of hand, without actually trying it....
I believe tat the problem brakes have been made wrongly, spokes wrong made....too thin or wrong material possibly.
We need a fe here with the problem, willing to swap the disk around.
Plus we could do with a few more qualified engineers here.
I am not really surprised though, seen it before!
regards to all
Andy

i think at the end of the day you get what you pay for as cheap tektro brakes ect will use the cheapest components possible and given the extra weight of a ebike 20kg plus are at there limit and the heat will just make noise and wear pads fast.

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i doubt many ppl would even think about spending that much on just the brakes and will only come with high end ebikes that cost 4k plus.

 

[Triple]

Temperatures on contemporary disc brakes (those with the tiny rotors bolted to the hub, rather than the out-of-fashion massive disc of yore) do rise and fall dramatically which increases problems no end, on top of lob-sidedly stressing forks and several other nasties which end up increasing mass - once seen as the ultimate sin in respect to bicycle engineering.

But these high temperatures do mean better performance in wet conditions, and they're perceived as cool.

I've a reasonable amount of experience with motor vehicle braking systems (including on the race track) and improving performance, it's a complex subject but fundamentally finding pads which work quietly and efficiently at high temperatures as well as low is awkward, if not impossible.

My suggestion? - find a combination which works for you and stick with it. And don't assume spending more necessarily improves results.

On my favourite bikes I'm sticking with the wonderful feel and power of good cantis, for now!

 

[trevor brooker]

i think at the end of the day you get what you pay for as cheap tektro brakes ect

What type of brakes would people recommend for ebikes then?

 

[Benjahmin]

The bike in my avatar uses Shimano Deore hydraulic with 180mm disc on the front. Tektro mech with 150mm on the rear. Did have some problem with rear pads, but solved it by using Clarks resin pads. I live in very hilly west Wales and these brakes do everything I ask of them - no problem. Bear in mind that it's a heavy bike at some 26-28Kg (two batteries etc.).
I have another bike with V brakes. This has a Magura HS11 on the front. Seems OK but I've never used it on the steeper stuff I ride, also never in the wet.
Now, I would always go for hydraulic on the front.

 

[sjpt]

I have another bike with V brakes. This has a Magura HS11 on the front. Seems OK but I've never used it on the steeper stuff I ride, also never in the wet.
Now, I would always go for hydraulic on the front.

HS11 are hydraulic (and not V). Do you mean you have another bike with rim brakes, and you would go for discs on the front?

 

[Nealh]

I use basic Shimano twin piston calliper brakes on all my bikes M395/446 type lever using B01S pads, pad wise I can use any type with icetech rotors.
The Swizzbee has a rear Magura HS33 which is very good and a hydraulic rim model.

 

[Andy-Mat]

i think at the end of the day you get what you pay for as cheap tektro brakes ect will use the cheapest components possible and given the extra weight of a ebike 20kg plus are at there limit and the heat will just make noise and wear pads fast.

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i doubt many ppl would even think about spending that much on just the brakes and will only come with high end ebikes that cost 4k plus.

My brakes are quite cheap, even the replacement caliper I bought when the plastic adjuster was made brittle and broke from sunlight (UV!) on the front wheel, a replacement caliper (what I needed) and a good thick disk, cost €11 (about 10 UK pounds?) on ebay, BUT, as I have mentioned before, both my original disks run in the "new way"!
Showing the UV damage:-

After my repair, with stainless steel parts, the adjuster now looks like this and is back on the bike:-


And in spite of very steep hills up in the forest behind my house, NO SQUEALING! Never ever......not from the original brakes, the repaired one, of the temporary spare caliper - all cheap!
My original bike disks are not quite as thick as the yet unused replacement.
But using both (original) brakes together (as always!), I can bring my bike under full control, to a very rapid stop....faster than any previous bike I have ever owned.
I might even add "breathtakingly fast!". So I am really happy with modern bike disk brakes.
There s a faint possibility, that my fine disk brake adjustment plays a role, as I do make sure that there is absolutely no dragging at all, as I can hear that, its not loud, but very annoying.
It would also waste a small amount of battery power.
When I first adjusted my disks/Pads on my current bike, I found that the front brake mount had been welded on, slightly out of position (1mm too far to the lest), causing the need for the "outside" pad to need to be replaced early, but adding two 1mm washers, moved the caliper to the right, this brought the pads into a more central position with regard to the disk (adjustment wise), allowing full adjustment/positioning of both pads and therefore allowing the full usage of the pad material, equally on both sides.
Andy
PS.The simple repair procedure I wrote is apparently too large for the server here, but if anyone would like a copy, I need your a "real" email address, a "throwaway one" would be the safest. If you have a plastic adjuster and need to replace it. I do not know how common this is....

 

[vfr400]

What type of brakes would people recommend for ebikes then?

For riding on normal roads, you don't need anything too special. Any well-known brand of hydraulic disk brakes will be fine. Everybody has their favourites, but I haven't noticed much difference between them. Juicy, Tektro, Shimano, Avid, Magura, etc.

OP has BB7 cable disc brakes. They're not a patch on even the cheapest hydraulic brakes, so I'd always replace them with hydraulics. Hydraulics are cheaper than BB7, they give better braking all-round, and they're more or less maintenance free.

 

[Triple]

What type of brakes would people recommend for ebikes then?

For most people, most of the time, cheaper disc setups (which is what most are despite a premium name) feel to work as well as cheaper V brakes, better in the wet. If you regularly ride through anything more than a thin layer of mud, discs make sense - they were designed for mountain bikes.

However, there are many compromises with discs including reducing comfort and increasing mass. Vitally, there are a couple of safety critical points worth mentioning - on a heavy bike down a long hill (I've yet to find an ebike which isn't heavy) there's an increased danger of overheating. This leads to very rapid fade, or with hydraulic actuation, boiling fluid, both of which mean little or no braking whatsoever.

The other is that a disc brake will try to lever the front wheel out of the fork dropouts rather than push it in, so well worth checking the skewer tightness a little more often than otherwise.

For any bike used mostly on the road, I'd always choose rim brakes - they're lighter (and allow a lighter frame/forks), allow tapered curving forks which offer much better bump-absorption at speed, easier to work on, they're more controllable so allow you to feather the brakes easily (useful through traffic) as well as helping an experienced rider bring the wheel right up to the point of locking without doing so (this is almost impossible with discs ime) and don't stress up a frame and forks (including headset bearings) unevenly.

 

[vfr400]

For most people, most of the time, cheaper disc setups (which is what most are despite a premium name) feel to work as well as cheaper V brakes, better in the wet. If you regularly ride through anything more than a thin layer of mud, discs make sense - they were designed for mountain bikes.

However, there are many compromises with discs including reducing comfort and increasing mass. Vitally, there are a couple of safety critical points worth mentioning - on a heavy bike down a long hill (I've yet to find an ebike which isn't heavy) there's an increased danger of overheating. This leads to very rapid fade, or with hydraulic actuation, boiling fluid, both of which mean little or no braking whatsoever.

The other is that a disc brake will try to lever the front wheel out of the fork dropouts rather than push it in, so well worth checking the skewer tightness a little more often than otherwise.

For any bike used mostly on the road, I'd always choose rim brakes - they're lighter (and allow a lighter frame/forks), allow tapered curving forks which offer much better bump-absorption at speed, easier to work on, they're more controllable so allow you to feather the brakes easily (useful through traffic) as well as helping an experienced rider bring the wheel right up to the point of locking without doing so (this is almost impossible with discs ime) and don't stress up a frame and forks (including headset bearings) unevenly.

Sorry to sound patronising, but how much experience do you have of riding an Ebike on the road? From your comments, I'm going to guess not very much. Anybody with any amount of practical experience riding normal electric bikes would know how much better hydraulic disc brakes are for such bikes. There's absolutely no comparison with rim brakes, which are maybe acceptable on light-weight road bikes, but are a liability on a 25kg electric bike with a heavy rider on board.