It’s always blown my mind how going through a single puddle can be enough to contaminate bike disc brakes, but cars can go 20000 miles in all weather conditions over many years and still be squeak free.
Car brake pads undergo much stronger forces that will tear off small layer of contaminants. If you use your bike in very hilly terrain this would have similar effect. Most problems with disc brakes whining is when people have their bikes on flatlands and rarely use them, the braking force they exert is not strong and long enough to deal with contaminants. When i mountain bike in hilly terrain with several hundreds meters of descent my discs are getting over 200 degrees easily, that will cook and shear off most of light contaminants.
@@heksogen4788 This is exactly the reason why disc brakes are total BS for most bikes, especially for city bikes in the flatlands. A proper pair of V-brakes or Magura HS 11/33 will do the job perfectly fine in almost every weather without squealing, plus easier maintenance. But no, now you get hydraulic disc brakes on 5-speed dutch bikes, I s*** you not... 🤦♂
What we do in our shop after sanding the pads is give them a once-over with a gas burner. gets rid of the brake cleaner fluid, glazes the resin and makes sure any remaining contaminants are gone for sure
I've loved reading all these comments about what alcohol to use, what brake cleaner, what grit sandpaper, baking bits on the stove... This is hilarious...defo won't be going to discs.
I use Finishline's disc brake cleaner and it's great. No need to wipe, brakes work better and brake noise is gone. Rim brake users should not be confused, as it is rare to need to disassemble as shown in the video.
It's not contamination, it's that flimsy thin rotor and the alignment with how badly the pads make contact with the rotor. It's a failed system. Yeah they work but this is the tech and the noise is something you have to live with or go back to rim brakes.
I went to a bike shop to fix my hydraulic brakes. Somehow I had problems with bleeding the brakes. So the nice technician gave me my bike back after his work was done. I went on my way and discoveres that my brakes werent working at all. He contaminated the brake pads while bleeding the brakes. Fun fact, I never went to that shop again and now I am the proud owner of two bleeding kits.
If you’ve got well worn-in pads, their wear might not be dead even so either remember which goes on which side or scratch an ‘l’ or ‘r’ on the back of the backing plate.
no one is asking you to upgrade. and RU-vid is rather new compared to 100 year old squeaky caliper brakes. get real and dismount your caliper horse, go invest in more chain wax equipment. more riders out there than ever, and fewer road bikers than ever in history.
Because it's newer tech, not everyone knows how to set up properly and clean. On rim brakes you still need to adjust, center, angle the pads, check for clearance, adjust the cable stretch… but as it's older tech, we got used to do it since we were kids/teens. Just think that if RU-vid existed in the 80's, there would be thousands of videos complaining that HG Shimano cassettes are trash and come from factory already worn out. Rim brakes are fine, but they ain't getting that much better after all these years.
By mistake I found a very good solution to contaminated brakes. I had a rusty set of pads on a bike kept by the beachside. I put them in CLR and let them soak for several hours. They came out very clean AND no longer squealed. I’m sold.
@@seanmccuen6970 I believe you're asking, "why use emery cloth instead of sandpaper?" Keep in mind that any grade of abrasive is designed to remove material. Emery 'cloth' is better suited for metal work than sandpaper because the cloth backing won't tear to shreds when soaked with isopropyl alcohol. 80-100 grit is sufficiently abrasive to scratch the metal rotor without scoring... If the brake pads are contaminated with brake fluid then they need to be replaced, such as what happens when the caliper piston seals are worn to the point where brake fluid can pass from the caliper to the hot pads/rotor.
A friend recently got into cycling. He took his bike in his car and when he reassembled his bike the brake pads were too close. I showed him one of your old videos and he fixed the problem by himself Thanks for all your great videos
Super helpful @GCN Tech! I'd love to know your favourite brand for brake degreaser and also what type of sand paper you use! My brakes regularly get noisy and I'd like to limit having to go in my LBS for something like this!
A light sand on a flat surface , wipe with isopropyl alcohol or cheap car brake cleaner, then hold over gas hob works for me (just be safe as brake cleaner very highly flammable hence keep the solvents well away from flames and room well aired!). Also lots of lowish price half decent pad alternatives / compounds out there these days too if your pads are almost worn out (some newer compounds a mix of compounds too) . You can’t compare with car brakes as they get far hotter and burn off contaminants plus brake forces far higher as servo assisted. Also when maintaining keep lubes and especially sprays well away from discs and pads - was how I contaminated mine.
All looks advanced on these discs and I am sure brilliant for those that experience the stopping power! But it was just 5mins for me to slide out my rim brake carbon pads on the weekend and slide in the new ones and get going.
Old toothbrush works great for cleaning the brake pads and acetone seems to work the best as a solvent. Also if they're still noisy cook them in the oven 20mins 220c.
One question..how has the car and motorcycle industry managed to make brakes for years that can get wet, have all sorts of road crud thrown at them, and not be noisy. In fact how have swissstop also managed it, but it is beyond the big brands like shimano?
I live in the montana mnts where around ever corner of trail there is a puddle, some dust, wet grasses, a brief snow flurry, then a dream crossing - my brakes are silent, metals pads, 10 years.... I have no clue what you are whining about. you sound like a squeaky rim brake. stop yer bitchin.
Car and motorcycle brakes have actual work to do like convert significant amounts of inertial energy into heat. Our little bike and rider combo mass was well served with simple rim brakes to slow down a couple hundred pounds. Our now toy disc brakes don't "scale" down so we'll.
On a multi-day adventure or when traveling with the bike, pack alchohol wipes from a first aid kit and give the rotors a little clean. Greasy fingers on the rotors are an easy contaminants to nip in the bud.
I almost always carry an alcohol based hand sanitizer, so when brakes start to squeak, I just spray on them. Temporary solution, but makes the ride more pleasant :)
The other day i encounter a set of very stubborn brakepads. I did exactly what you did here and it didnt work. When the pads went under the bedin process they immediately squeak. So, the solution was cleaning the pads with MEK ( some white spirit like solvent) in the ultrasonic cleaner for 10 min and repeat all te process. I think the gime was stuck inside and under heat it sprouts out.
When I was a teen post bike crash i needed a bike.....for my daily commute and paper round. I went to halfords......brought an apollo, during the hurried assembly the clowns sprayed oil on the brakes to stop the squeel... Yep my east end father went mad......one empty store later and new pads toed in correctly with clean rims , i got my brick of a machine for work. It was a metric ton heavier than my TT shorter . Havent used halfords since, built my own.
So far Much-Off disc brake cleaner is done the job very well.But it depends of course how often you clean brakes and bike and what kind of weather you ride.
Works sometimes for sure, but not all the time. Have yet to try the flame trick, would a BBQ lighter flame get hot enough or do you need the blowtorch/gas stove? Once I get a combo of pads/rotors that stop and don't squeal a simple wipe-down of the rotors with alcohol-based window cleaner seems to keep it that way. The only real problem I've had with squeal has been with Shimano Ultegra calipers and rotors. That bike took swapping the rotors out for the cheaper, single-piece Made-in-China versions and a set of Swissstop pads to finally get stopping without squealing!
The pistons needs lubricant to work properly. Be careful with disc brake cleaner as can seize the pistons, they need to be fully retracted. Or re-lubricate them after.
I'd add a cigarette lighter to the tool kit. Heat up the rotor and the pads a little. This burns away any contaminate. Then clean and run down the surfaces. You could just be moving oils etc around if the spray doesn't get it. It works for me!
What grit of sand paper would be good? Seeing mixed answers, saying 40 is too low, 80 is too low, 90 is good, 150 is decent, 300 is good but might be so fine it isn't effective
I've heard a theory that disc brake noise is often down to grooves in the disc rotor and that these need to be smoothed out from time to time, any opinions on that ?
I've noticed that semi metallic or metallic pads are much less prone to contamination, if they start to squeak the only thing you have to do is to climb a hill, apply the brake at the top and release it at the bottom, the squeaking will be gone 😊
Rotors and pads that are dirty are not contaminated. Contamination refers to substances that are now embedded in the pads and no matter how much you clean them will not decontaminate them. No amount of sanding cleaning or heating can decontaminate pads that have been contaminated with petroleum/hydraulic based products or debris that are now embedded within the fibers or pad material. Dirty rotors and pads can be cleaned sometimes very easily sometimes it takes more effort.
200-300, doesn't matter much to be honest, it's just about scoring the surface, but not polishing it. I also swear by proper bedding in brakes after it (Park Tool has great video).
Here is a great trick….ride up and down the road in front of your house for 5 minutes with the brakes barely engaged. This will get them really hot. After 5 or so minutes, spray the rotors and calipers off with cold water from the garden hose. Allow it to dry. This will remove contaminates.
I used Fenwick's disc brake cleaner to clean my rotors and calipers but I did not remove the pads but this did not work. I have Silca's Gear Wipes so I thought I would try cleaning the rotor with a wipe and this resolved the issue. Now when cleaning my bike I use Muc-Off disc brake covers to prevent any contamination when cleaning the rest of the bike and I just wipe the rotors with a Silca Gear Wipe. Since doing this I do not experience any squealing at all even in the wet. I use Shimano Ultegra 8100 brakes with the new RT-CL800 rotors and the L05A-RF brake pads resin with fin. I have found this combination to be by far the best as I was using different lower spec Shimano pads before which were not very good. The finned pads also look cool, the SILCA Gear Wipes are very expensive but they are also very good for cleaning your bike in general. Following Shimano's bedding in process for new pads is also very important before you start using them.
Did all this - several times- butt the front brake stil noisy, changed front brakes completely to the Back and reverse ( so the noise shoud go also to the back) butt NO my front brake squeeze and the back brake no noise😵💫😵💫😵💫
This has definitely put me off changing to discs..what a faff. Rim brakes hardly need any maintenance in comparison...just clean your rims and change the pads when they wear out which is after about 10000 miles.
#askgcntech hi team, hopefully someone can help. I have a trek emonda sl6. it has a fun trick of the internal frame filling with water ..... which causes BB to need replacement frequently, 4th in 2 years 100km on it amainly good weather but get caught by irish summer so will occasionally be in rain. there is a weep hole that ive tried pipe cleaners and all on but still if out on rainy day fills like a ballon, when i stand up on back wheel all water runs out theshifter cable hole at back and if on frint wheel goes out headtube. Local trek suppliers have suggested taping up holes around shifter and headset.... which doesnt seem like an ideal solution. is there any advice from you or puublic that may have similar issue
When that's actually worn out or near worn out, it's straight forward and intuitive. If you ever wonder this then the pads are just OK. When it's very thin like "paper thin" then it's time to replace.
There's alot more to it than these simple go to's , if the rotors are badly grooved they'll act like a vinyl record playing a tune & if the pads are hitting rear first they'll judder hence vibrate/making a screetch just like rim brakes towing in at the rear does.
for me it's not worth the time and effort (the process, not the video)... go directly to 4:25´s piece of advice... pads are porous, dirt it´s not only in the surface... you need to remove a lot of material and use a lot of product for a kind of random result... just an opinion... thank you for all the content...
Disk break pads is a failure - they can't create proper pads which will be silent in wet/rain. This is really annoying, especially when in your country rains a lot! Don't tell me 'contaminants' joke story - spray clean water on breaks and you will get crappy sound, when it dry pads get silent again. If pads dry and you have still sound - only then meens you probably have contaminants on the pads, and you need to burn them or clean
None of my 7 bikes squeal because they all use rim brakes. My son used to have disc brakes on his bike but we could never stop the rotors rubbing the pads so now he has a rim brake bike.
I've done all that to my Ultegra calipers etc, the barstarding things still squeal like a stuck pigs even after changing to new pads!!! 🤬🤬🤬 im now wondering if there is reasonance building up between brake pads and the caliper pistons, im debating putting a very, very light coat of copaslip twixt the two? Anyone got any thoughts on that?
I suggest you ensure you use Organic/Resin compound pads. Bed in easy, have a tendency not to cause squeal on operation, have better modulation. I believe for the majority of riders this compound is the better choice. I think because tthis pad compound are cheaper, hence a lot of people’s perception is inferior, but unless you are doing very fast and long descents, resin pads are normally the better choice. PS, if still squeal, ride or be taken to a very steep and long hill and pedal down, dragging the brake, if still do, repeat and with Resin pads, very likely problem will be solved.
Cheers for that, I'll give it a try, didnt have that problem with my Tcr currently running shimano 105 calipers/pads/ice tech rotors (shortly to be Ultegra calipers, ice tech discs and pads!)
If your brakes sound like that, chances are you just haven't ridden that bike for a while. A good long ride will shave off the contaminated layer and you should be good to go. No need to do anything else.
