I am guilty of all of the above.... my last event I went on my the end of mile 200 I was being called '... the squeaky brake guy...' I just started answering ... yeah easier for you to hear me coming.......REEEEEEEEEE....🤪
Resetting pistons into the caliper without removing bleed screw in the lever first, causing a leak in the diaphragm in the lever. My tip, ALWAYS remove the bleed screw in the brake lever and install a bleed bucket so any excess fluid has somewhere to go instead of bursting the reservoir. Also: NEVER add brake fluid when the pistons are not fully reset into the caliper, avoid overfilling the system at all times. Added benefit is that you allow the pistons to retract optimally after braking, preventing sticky pistons.
If I can offer a few tips: Whilst very easy once you have the right tools, they're (relatively) easy muck up if you go in unprepared! It's worth bedding them in - ride on a flat road at up to 25kph, brake hard, and release before you come to a stop. Repeat 4-5 times. The braking effect will improve with each pull. If they're screaming, the pads/rotors are contaminated. Isopropyl alcohol is a very good cleaner (be careful to avoid skin contact) Alignment tools are helpful, but not essential. Once set up you shouldn't need to change the caliper alignment. The piston reset tool is actually really helpful, you don't need to buy park tool (look at the lifeline one) If you ever need to cut hoses, get the right tools. Don't try to use the wrong ones. You'll end up with bad results. If you run SRAM - DOT fluid is nasty stuff. Wear gloves and sleeves. Mineral oil will dry your skin out (if you repeatedly get it on you) but it isn't going to hurt for the most part. Gloves are useful to prevent contamination. Bleed kits are cheap, and bleeding is relatively easy. Just go in prepared. A small amount of rub is annoying, but is often dirt. If it persists after cleaning check your rotor is straight, but also reset your pads.
Makes me wish I still have my rim brake bikes - well, I still have a 2007 SystemSix with 23C tyres - aluminium rims, Ultegra brakes, stops as well as makes no difference as the 2018 Roubaix with hydraulic Ultegra. Life was simple then. Just used a Campag bottom bracket spanner to hold rubber washing machine foot while I tightened locknut. Reminded of pre-dual pivot brakes when I had to pull out the Weinmann brake tool for a friend's old bike - that was when brakes were not good
A word of caution using a vernier caliper to measure brake rotor thickness for wear.. Be mindful of the "lip" some brake rotors develop over time if the brake pads happen to be set slightly inwards of the very edge of the braking surface - you _will_ get a false reading of you unknowingly measure that lip instead of setting the vernier's jaws inward onto the actual braking surface.
Road bike disc brake: don’t touch it don’t clean it with cheap product keep make it clean as you can Also disc brake but MTB: what are u doin bro, why we have to clean rotor
Resin and scintered / semi-metal pads. Not sure if only Shimano uses rotors that should only use resin pads (is written on an arm of the rotor, "Resin Pads Only"), but it certainly is good to check. If it says Resin Only, then use resin pads. "Metallic" pads chew up the softer rotor metal. I have found it is okay to go the other way, use resin pads on rotors that can handle "metallic" pads. Also, some rotors are narrower than others (something like 14mm vs. 16mm) and pads should match the rotor width. If not, the rotor will likely undercut the pad near the top, or the pad will not reach the top of the rotor and leave an overhang / ridge at the top of the rotor. A final comment, don't let rotors get too worn or they could break apart during use. One of my customers had this happen on a rear wheel when stopping at a light in town - instant wheel lockup. Another customer had 0.3mm (yes, i could bend the rotor back and forth with my fingers) on his FRONT rotor. He is extremely lucky he did not do a Superman imitation on a high-speed descent.
Aword of warning on resetting your pistons. After watching a few videos and reading through the literature, I decided to replace my own pads. I used a plastic tire removal lever to reset the pistons, then put the pads back on. After a few rides I noticed I was losing pressure/fluid in my left lever. After discussing with the local bike shop mechanic, it turns out that Shimano levers (mine are Ultegra Di2) have a small bladder inside the lever that can burst if you push on the pistons too hard. He said his shop discovered this only after experiencing a few similar mishaps. I went through all the available shimano documentation as well as a few more RU-vid videos, and found only one individual who warned about this issue. Fortunately Shimano replaced my ($450) lever under warranty, but others might not be so lucky.
Ohhh jesus, I just reset mine but have no idea what is considered hard, so will have to be careful 😬 don't wanna leave home and head into the 250m vertical loss descent and have no brakes
I think the same thing happened to me. My bike mechanic fixed it somehow without replacing the bladder (pulmone in Italian). I've done multiday events n thousands of kms with it since.
Even after all that if it still makes noise, you might need to get the frame/fork caliper mounting surface faced. I had this issue on my Salsa Warbird. No matter what I did it would howl and screech when breaking. It’s because the caliper/rotor wasn’t absolutely in parallel with each other.
I use to be a bike mechanic. A trick that no one will say is that you can restore heavily contaminated pads. Take the pads off, spray with brake cleaner and set fire to it. Be careful not to spray too much or the long burn can detach the braking material from the mount. Do it outside over a hard surface or on a metal table. U'r welcome
I have never tried disc brakes, so it’s possible that I might actually like them better. But I find that my Shimano Ultegra rim brakes on my 1997 Serotta Atlanta have never left me wanting for more. Even the cheep Tektros on my 2010 Rocky Mountain AC30 (an entry level bike if there ever was one). I found myself laying my belly on the seat and riding an endo of sorts with my rear wheel dancing so to an inch above the asphalt (tarmac) under aggressive braking. So I’m not sold on the idea of disc brakes that require reinforcing of the frame and forks. More weight, more wind resistance, messy hydraulic fluid, stronger spokes, and other issues like proprietary discs. I think if I were putting together a bike I rode in the rain, or a gravel or mountain bike that saw mud. I would probably switch in a heartbeat. Until then, I’m still happy with my rim brakes.
There are plenty of new bikes being sold that have rim brakes still, and several companies making rim brake parts (to modern standards). They're not at all obsolete. The only time I could foresee benefitting from hydraulic disc brakes is going downhill at 70 kph.
Always check your brakes and rotor before riding. I discovered how to keep my pads from rubbing. When adjusting the bake caliper I insert a 5 mill brass shim between each pad and caliper or pad and rotor then remove it after adjusting.
Finally some one covered replacing brake disc's, good job, I replace mine every time I change the tire on my ebike, I noticed a major issue with bicycle floating brake disc's, every brand I used has been made with very thin steel washers that can rust out and fall apart ! And the one brand I found that used stainless washers, were just too light weight, by removing too much metal for me to trust, heating and cooling can cause fatigue cracking. 😮 Im building my next ebike with moped / motor cycle size brakes , they cost about the same last much much longer give much better braking for like a pound and half of extra weight, IMO in general the bicycle industry has lost its mind with trading less weight for strength 😢 ultra lite weight components belong on a circle track, in a controlled environment not in the real world. I
Before pushing the pistons in, clean them! Otherwise the dirt might move in and prevent the piston to move smoothly. This might also cause scratching noise, as the pad might not move away from the rotor…
Yesterday I cleaned my pistons with an ear cleaner and then wiped brake cleaner around the edges and massaged the pistons in and out. Haven't been for a ride yet but they seem to be retracting better in the workshop stand 🙏 🙏 🙏
I didnt notice I ran a narrow rotor with a wide pad for several years on my commuting bike. The pads were using part of the rotor arms as a braking surface. Lesson learned: match wide pads with wide rotors!
Lever height adjustment gauge (to be used in conjunction with a hanger alignment gauge). BSC Tools (U.K) and Abbey Bike Tools (U.S) made theirs, with the former being the first to do so.
If you don't have a digital caliper, just get one. It's a useful measuring tool. They should be available in hardware stores and even in Lidl, and cost about the same as a pair of pliers.
Yes it's odd that he suggests a bunch of special tools for separating stuck pads, straightening rotors, and resetting pistons, , but when it comes to a very general purpose and useful tool like a caliper... well, you probably don't have one of those, go to your bike shop! 🤷♂
It don't has to be a digital one necessarily, you even get non digital ones which have 1/50 mm. You can read the 1/50 mm not really good on them but 1/20 are the more typical ones and they are excellent to read and you can also read 1/20 on a 1/50 mm scale.
Be careful when measuring. The pad doesn't always press on the whole width of the braking surface. If the outer edge isn't worn by the pad you need to avoid measuring that part by accident.
As an owner of a small car I have two loose "transport-axles" to put on my frame, with a small plastic clamp on a wire, to secure not accidentally compressing my XTR brakes during transport! And also a small plastic wheel on one for holding the chain, during that. I also use a large bag for my XTR wheels, for protection. The Disc edges are very sharp, so I like to be out of reach from anything to be cut!
Watch out for weird rotor sizes! My 2009 MTB had 185mm rotors. I replaced them by 180mm and the pads didn't cover the complete surface. I had to replace the IS/DM adapters too.
I had no idea about measuring the brakes. I do have a measuring tool I could use--just need batteries for it. Brakes are fine though. Barely use the disk brakes on the fat bike, and the road bike is less than a year old. But still good to know about it and I should check them while they're still relatively new to gauge the changes over the years.
My gravel bike frame has IS mounts for disc brakes, so I had to pair my GRX400 levers with Deore M6000 calipers. I’m not sure if MTB calipers have wider clearances, but rotor rub has never been an issue for me… unless it gets really muddy.
Surprised there isn't special Ultimate Disk Brake Microfiber available on the market that's five times more expensive than non-special but perfectly fine for the job one
Disc brake pads are marked L and R on the backs. Pay attention when you take them out (for example when cleaning the pads or pistons)! They probably won't wear 100% evenly, and reversing them can cause pad drag! Also, clean your pistons every once and a while. They get gunked up with grime and can stick, and cause drag as well.
@@gcntech no, this is the reason I swichted to a front disc brake on my heavy commuter. It causes far less maintenance, just a set of pads every 6 months. The frame don't has a disc mount at the rear, so the rear is still rim brake (but this is not a real problem)
@@gcntechoooyeah! i’ve never had a bicycle with disks, but every motorbike i’ve had has needed a strip down & clean up every few months because they’ve started sticking/dragging, not just the cheaper stuff, even Brembo were like that. The clearances are so tight that it’s pretty much inevitable
They are just a lot more finicky. Can’t touch the rotor or pad, can’t get and cleaners on them, pads need frequent adjustments to not rub, pads and rotors need frequent replacement. Rim brakes don’t rub, don’t need replacement very often. You just set them and forget them. Rim brakes are better than disc brakes in every way except for braking.
I would add that discs are very sensitive to bad weather. In heavy rain half the braking force is immediately lost. Pads begin to wear away like they're made of chalk. Sand and dirt from the road score the discs. Mud, road salt and other things wear the piston seals and they begin to leak oil. Not to mention the fiddling around with bleeding them from time to time. To alleviate some of the headache, I replaced the hydros on one commuter bike with mechanical disks. A mechanical that works is better than a hydro that doesn't :)
@@PRH123 Disc brakes are 100x better in wet weather than rim brakes. As a 15 year daily commuter in Seattle my disc brakes start braking almost immediately in wet weather. In wet weather w/ rim brakes put a death grip on the lever, in about 100 feet the brakes start to grip. You can actually feel the effect of water being "squeezed" off the rim and heat building up enough before the brakes begin to slow you down. Do that w/ disc brakes and your wheels lock up pretty quickly, even if wet. Then if you ride a lot in all conditions you need a new wheel b/c your rim brakes have worn through the side of the rim. Pads & discs are cheap compared to a new wheel or rim + wheel build labor. I had a rim blow out on me b/c my rim brakes had worn the sidewall of the rim down over a few years of regular use. Disc brakes take a bit more regular maintenance, but I wouldn't go back to rim brakes for anything!!!
Personally disagree (but understand where you're coming from), I had to clean my rim brakes much more thoroughly for consistent results. IMO it's just that the maintenance is achieved with different tools which many don't yet have and (as yet) many cyclists aren't used to maintaining discs. But I could be biased, I massively prefer the braking feel and power of discs, so might just be willing to fix the issues when they arise!
@@twatts4436as a mountainbiker I use of course disc brakes, but I also have some rim brake bikes. Maintaining the disc brakes (like brake bleeds) need definitely more skills than maintaining a rim brake. As a hobby mechanic this isn't a real challenge for me, but some people may struggle here. However some people also can't change a tire, so this is why bike shops exist
Nah, anyone familiar with automotive disc brake system now they go through absolute crap piles of contaminates and run for tens of thousands of miles. Bike disks are certainly of a much smaller scale but so are the braking loads. While I'm not saying to be mindless and not give a crap about getting contaminates on them, they'll still provide plenty of clamping power. I used rim brakes for some 40 years and recently got a bike with disks. They're dead simple and in no way need babying.
Make sure you center your calipers on your disks. You do this by loosening the screws that hold the caliper (don’t remove them). Then squeezing the brakes until they grab on, then tighten the bolts
Contamination on pad tip - remove from calipers, hold with pliers, hit them with a torch for a few seconds. It burns the oil and grease out of them. Let them cool, sand the face to remove the burnt stuff, and reinstall. Not too long under the flame, don't get nuts, do outside, and any other safety stuff please do. Works great.
To avoid disc rub, be consistent with the wheel position when you tighten the axle. Align the valve with the fork or seat stay. Loosen the axel so the wheel can move. Use gravity to push the bike onto the wheel in what ever position it will do every time. Tighten the axel. Now loosen the brake mount bolts, squeeze the brake lever and while squeezing tighten the mounting bolts. Adjust the mounting bolt torque to the proper value. Your pads should not rub. Every time you reinstall the wheel align the valve to the frame as you did when you set the brake location and use gravity again the seat the frame onto the wheel then squeeze the brake lever as you tighten the axle.
It would be better to sit on the bike while tightening the wheels, if the gravity is important there😂 Maybe with QR disc brakes it have some sense but with thru axle bolts it has no impact, it can make things even worse...
Great Information! Kind of a beginner rider, what is the best time for shifting gear when pedaling or stop pedaling and shift? What is better for my bike chain?. Thank you a lot!🚴🚴🚴
Keep pedalling but just before you select the next cog, reduce the pressure on your pedals slightly, just for one turn of the crank, and your chain will pick up the next cog beautifully, then you can get back on the power.
If one lives in a hilly or mountainous area, disc brakes are awesome. If you live in a flat area where the brakes don't get much of a workout, they simply aren't worth the effort. In that case, rim brakes are simpler and require much less maintenance, despite the marketing hype.
I do most my riding along so-cal beach paths, my rim brakes have 5000 miles on them, and the pads aren't even a 1/4 done. The whole disk brake thing is a money grab. If they made hydraulic rim brakes they would be better, outside of carbon wheels as its essentially a giant disk, much greater heat capacity, better leverage on the braking surface since its so close to the tire. If the goal was actual performance it would be hydraulic rim brakes.
I have 1 ride that is a mountain decent. I have to use lots of brakes. Mt. Hood with 15 mile climb and 15 mile decent. I'll sacrifice some rotors for safety.
The rider who drags the brake down the entire descent is probably the driver who rides the clutch. Oh yeah, the clutch is the left pedal on the floor (not the parking pedal). If you haven’t seen it yet you probably don’t have one.
It's possible to bend the rotor by keeping the brake applied while halted after a long descend, the heat cannot escape from the spot where the pad is touching the rotor causing an uneven heat dissipation of the metal and bending occurs. This is also why you should not apply the brakes in a car when halted after braking.
My wheel appears to wobble. Would that be the cause of disc rubbing? Or can a wheel wobble independently from a disc rubbing? My bike was shipped to me for some assembly; I heard that the disc brakes can be damaged in transit. I could see the wheel wobble when I took my first spin, and I could hear the mechanical disc brake rubbing at the same time. My powers of observation were not strong enough to tell if the two things were in sync.
Nervous riders ride slowly downhill dragging their brakes thus putting 90% of their gravitational potential energy into the brakes. They are toasted. Ride down same hill with minimal braking, putting that same energy into wind drag then brake to a stop at the bottom of the hill (or whatever if you need to make a turn) and only much smaller fraction of the energy goes into the brakes. Prove this to a newbie friend and save their brakes from becoming toast!
That ParkTool digital guage looks identical to what I got from Screwfix or Toolstation - almost certainly for a fraction of the ParkTool price. Different colour, of course
I mean, digital vernier calipers all look extremely similar, from the $15 china type to a $300 Mitotuyo caliper. Doesn't mean there's no difference between them. For a lot of simple jobs the cheap ones will do though, just depends what you expect of them.
@ska042 True. I usually use pro tools for DIY construction and have 50 years' worth of mostly good tools for bike maintenance (can't find my wheel jig). I do know my digital measure is as good as it needs to be
I just use 91% isopropyl alcohol to clean the rotors. Works perfectly. Also there are hard plastic non marring rotor truing tools that are common. One came with my bleeder kit. It is very simple to true your rotor. You can use a plastic tire lever to split your pads apart and also press your pistons back in.
I appreciate the special permission fornthe A-Team to us babyoil. (Did they ever ride bicycles? Indid not rewatch since becoming interested in bicycles.) I doubt, they would have had hydraulic brakes on bicycles back then, though. 😜
personally when cleaning my rotors i take them off and wash them with hot soapy water, then dry and clean again with 99% iso alcohol. this gets everything off them, . pad flat surface, figure sanding, 400 grit till they have that matt new look. rebed in
You should be able to get spray disc brake cleaner at any motor factors / auto parts shop, designed to do exactly this, no need for soap & water & alcohol & sandpaper - much easier!
@@edwardsjohnpaul i've used automotive disc brake cleaners in the past, they usually leave a residue that bike brakes don't get hot enough to burn off unlike car brakes do. may way always leave them compleatly uncontaminated.
Be careful when you put your wheels back in after taking them off. The rotor could scrape against the droupouts and stays, gouging away both paint and metal. Not had it happen myself, but seen it happen to others.
Let me think... 🤔 Alex would triple-check that the setting was correct. Ollie will not ever blame himself. Si seems to ride brand new bikes only lately. Manon is too careful to do that. Dan does not even ride now. Hank rides but doesn't use the breaks too much. And Conor... well, it must have been Conor, isn't it?😂
Definitely not Ollie, he would have gotten agitated as he talked about it 😂😂 Also I can't see Hank doing any of his own maintenance so whilst he is more than capable of such a mistake in his eagerness he would have gotten Alex to do his maintenance jobs. I too suspect Conor.
@@SebMercier Conor is the type of person to pick up and fit the wrong rotor size by mistake. Despite his taller frame he isn't as harsh or demanding as Hank who is naturally an aggressive rider by enthusiasm. He would notice that they weren't as powerful as he was used to.
Yea using the wrong fluid... I have tried Baby Oil but that didn't do it too well. Am running my Shimano XT's on Citroen hydraulics and not so bad really.
#AskGCNTech I am currently riding a 2014 Merida scultura 904 and it has 50mm carbon wheels, I am very not happy with the stopping power, especially in the wet. I have priced it up and I can do an upgrade to a disc front fork/wheel/cable actuated hydraulic calliper for about $600NZD (about £300). I can't upgrade to another similar bike for this price as my bike is almost brand new (yes, even the frame has done less than 1000km). I am planning to keep the old fork and brake for when I sell the bike if I ever do. As I understand it, most braking is in the front of the bike so my question is: is this likely to improve my braking on descents and in the wet, and am I missing anything that might be a problem later?
Using a disc in the front is fine. Since the new fork is made for disc there is no problem. You only have to find compatibility with your brake lever/shifter combination, but with the mechanical hydro caliper this is also fine. TRP Spyres may be an alternative to the mechanical hydro caliper, they have a relatively good reputation too.
Best of both worlds with front disc / rear rim. You could even look for a hydraulic brake shifter to have maximum power upfront. Rear wheel changes will still be fast with a rim brake and it will be lighter than a full disc frame bike.
I find that the benefits of riding them in the wet weather it’s not all it’s supposed to be, grim and oil off the wet rd easily gets on the rotor’s and stopping is not that great if anything worse than rims, luckily it’s not like that on all the wet rides.
Off topic. I don’t understand the applications for road tires. What’s the difference between racing, training, and all weather? Slicks vs different treads? Thanks.
The main differences across different tires are the compound and casing. Treads don't matter so much especially when you're talking about hydroplaning because road bike tires are too narrow to make it possible.
8:36 i have had this happen on a fat tier ebike and i did not know until i brought it into the shop to have the breaks taken a look at they told me the ones that where on it where trash and i got an up grade on the breaks and cable
Alignment Uneven pad spacing Fraying cables Badly cut housing Not cleaning the pads and rims Wrong pads for the rim material (unless you want to wear out either the pads, or rims) Spray and pray lube (again)
Another tip with steep descents where you need to ride the brakes. Alternate between using front and rears every few seconds. Still gives you the braking effect but you allow your brakes a brief breather to recover. Obviously only do this on straight bits of road.
They are much more hassle than pull brakes. I’ve spent hours and a fortune on Giant conduct replacement bleeding by shops and myself and pads. They still give me less confidence than pull and are only better in some conditions.
In a panic situation the front disc brake will be glad to lock on you, throwing you over the bars and letting your wife collect on your life insurance policy.
@@kwitwerikok8o863 I've seen my dad fly over the handle bars in such a situation with V-brakes, and I still consider those quite unsafe. Discs on the other hand give you much better modulation even if stressed, so this is a disadvantage that I am not seeing. Therefore they make perfect sense on MTBs or e-bikes, but on a road bike you can use a much smaller rim brake because they are lighter.
For me, it is not about the discs: it is about the hydraulics. Once i tried hydraulic brakes, i never looked back. It's like cutting with a slightly dull knife vs. a newly sharpened knife.
I'm a bike nerd and I don't mind doing my own maintenance. I appreciate the braking power and modulation under harsh conditions. I have both disc and rim brake bikes. But people ask me often what kind of bike they should buy and I tell people to avoid disc brakes if possible. The rules and regulations of Disc Brakery are insane. This video is exhibit #425. But nowadays even cheap bikes have disc brakes, they're becoming hard to avoid.
I think for normal non-cyclists, a mechanical front disc brake and rear rim brake makes sense for foul weather braking performance, service and replacement. Belt drive with a 3-8 speed hub too. But these days, sadly, the normies are mostly getting e-bikes.
I've used 99% isopropyl alcohol on rotors multiple times, no issues. Even automotive brake cleaner should be OK. Either way, they're more affordable than the likes of Muc-Off.
The only advantage I can think of for DOT fluid is standardisation. Because of that, you don't have to stick with the same brand of DOT fluid, as long as the DOT fluid type matches.
It'd be great to have a GCN science video where you go over how/why certain materials turn your brakes into banshees. This happened to me after I washed my bike, and I'm not sure what mistake I made (degreaser onto the brake pads/rotors? dish soap onto the brake pads/rotors?). I'm now afraid to wash my bike :/
Ok. Further on in video and reading comments... Time to park the 2018 Roubaix with Ultegra hydraulic disks and get back on 2007 SystemSix. Except: UK road surfaces are so bad nowadays that 23C tyres and narrow rims get damaged more than old days. Still, (27*1¼)" tyres on Weinmann concave rims with Shimano 105 dual pivots to replace Weinmann 500 brakes had plenty of stopping power and control in 1970s, even in wet, and could handle the wide rims and tyres
You could look for a cantilever or V brake cyclocrosser and run 32+ mm tires while still having rim brakes. Cheap too. There are carbon cantilever frames and bikes if you look for one, or all the Al/Fe/Ti metals too.
