Disc brakes 2019
09-17-18, 07:49 AM
#51
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I have had both and I do not like disks.
1. Disk brake pads wear out rapidly. Unlike a car there is no fluid reservoir and no power assist so the entire brake operates with manual high ratio lever pull. This means that it doesn't require much wear before the lever bottoms out. The only way to "adjust" this is to replace the disk pad. Looking at the disk wear after just a single hard ride should tell you that these brakes because of their relatively small size and disk diameter have a lot of wear. People that are saying that "My brake pads don't wear out" do not ride their bikes much.
2. A rim brake is attached to the fork head or the intersection of the seat stays and since they rub against the furthest outer section of the wheel and the brakes are at a very strong section of the frame they are very safe. This is why we are seeing "skeleton" brakes by all manufacturers and even smaller companies such as Bontrager who while owned by Trek still have to show a profit. Light is what we're talking about and so lighter brakes because of less forces against them are the password.
3. Disk brakes are at the worst place possible on a fork. They are at the end of a long lever and have to transfer all of the majority of the braking force through the entire length of the fork and into the frame. They don't have 12 mm axles on these bikes because they don't need them. While MTB forks have to absorb horrendous forces and are strongly built because of this, a road bike fork does not and putting disk brakes on them makes heavier forks than would otherwise be necessary.
The disk brakes are here for one purpose and one purpose only - as nothing more than a sales gimmick - something new for you to need and something new to increase the profit margins on bicycles. Teams are sponsored by bicycle companies in order to advertise their products so they are not going to complain one way or the other.
Now all of you people who sprung for a disk brake may attempt to defend your purchase by telling us all how disks have a lower "wait" period for braking in the rain. After all, we all ride in the rain so that is handier than lightly touching a road brake for 2 seconds before applying it heavily.
Or that they brake more than rim brakes despite the fact that you can lock wheels with either and that the reason that they put smaller diameter disks on road bikes is because they were far too sensitive and were locking too easily. You can also tell us that you don't care that there is no disk/hydraulic system or wheel locking system or rear wheel width standard because you're happy with what you have. That's fine until it is discontinued. Like the Campy 10 speed levers you can't get spare parts for them after they made the 11 speed standard.
There are two reasons for changes in standards - improvements and sales gimmicks. While massive numbers of gears are useful for pro racers they are not for Joe Everyday Rider. Disk brakes can only be said to fall under the mantle of "sales gimmick" and my bet is that they will disappear rather quickly.
1. Disk brake pads wear out rapidly. Unlike a car there is no fluid reservoir and no power assist so the entire brake operates with manual high ratio lever pull. This means that it doesn't require much wear before the lever bottoms out. The only way to "adjust" this is to replace the disk pad. Looking at the disk wear after just a single hard ride should tell you that these brakes because of their relatively small size and disk diameter have a lot of wear. People that are saying that "My brake pads don't wear out" do not ride their bikes much.
2. A rim brake is attached to the fork head or the intersection of the seat stays and since they rub against the furthest outer section of the wheel and the brakes are at a very strong section of the frame they are very safe. This is why we are seeing "skeleton" brakes by all manufacturers and even smaller companies such as Bontrager who while owned by Trek still have to show a profit. Light is what we're talking about and so lighter brakes because of less forces against them are the password.
3. Disk brakes are at the worst place possible on a fork. They are at the end of a long lever and have to transfer all of the majority of the braking force through the entire length of the fork and into the frame. They don't have 12 mm axles on these bikes because they don't need them. While MTB forks have to absorb horrendous forces and are strongly built because of this, a road bike fork does not and putting disk brakes on them makes heavier forks than would otherwise be necessary.
The disk brakes are here for one purpose and one purpose only - as nothing more than a sales gimmick - something new for you to need and something new to increase the profit margins on bicycles. Teams are sponsored by bicycle companies in order to advertise their products so they are not going to complain one way or the other.
Now all of you people who sprung for a disk brake may attempt to defend your purchase by telling us all how disks have a lower "wait" period for braking in the rain. After all, we all ride in the rain so that is handier than lightly touching a road brake for 2 seconds before applying it heavily.
Or that they brake more than rim brakes despite the fact that you can lock wheels with either and that the reason that they put smaller diameter disks on road bikes is because they were far too sensitive and were locking too easily. You can also tell us that you don't care that there is no disk/hydraulic system or wheel locking system or rear wheel width standard because you're happy with what you have. That's fine until it is discontinued. Like the Campy 10 speed levers you can't get spare parts for them after they made the 11 speed standard.
There are two reasons for changes in standards - improvements and sales gimmicks. While massive numbers of gears are useful for pro racers they are not for Joe Everyday Rider. Disk brakes can only be said to fall under the mantle of "sales gimmick" and my bet is that they will disappear rather quickly.
a). I have disks because I don't have to clean the rims every weekend; I can if I want to, but I don't have to [in order to keep effective *********** and rim wear].
b). I think disks are here to stay. Someone mentioned above that after some years, only cheaper bikes will have rim brakes and that we are in a transition period the same the MTB world was back when.
Another point: someone else mentioned further up that if the UCI removed weight limits, disk brakes would instantly become a thing of the past. Yes, agreed to this.
09-17-18, 07:57 AM
#52
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Oh goody. This thread has turned into a "which is better" debate.
09-17-18, 08:03 AM
#54
Non omnino gravis
Hey, I'm just hanging around to find out how the engineer thinks hydraulic brakes work.
Because all of the stuff he's posted in this thread up to now is just bonkers.
Because all of the stuff he's posted in this thread up to now is just bonkers.
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09-17-18, 08:04 AM
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Excuse me - I assumed that you would understand that I meant "single vehicle accidents" which that overwhelming majority of bicycle accidents are.
09-17-18, 08:30 AM
#56
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I'm too lazy to go back an read this entire thread to understand what you are talking about, so I will take you at your word.
09-17-18, 08:36 AM
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I see that even though this entire conversation was about disks on road bikes that they cannot keep themselves from illustrating everything with MTB components. And even though I said that I believe that they are good on MTB's where the extra weight is offset by the extra power and the strength of the suspension forks and the added strengthening of the rear triangle. I wonder why they think that a road tire has the same traction as a 2" knobby in soft ground?
I also see that they do not understand the effects that a reservoir on disk brakes has in a non-powered set-up. I could explain it to them but I think I will leave them to not-ponder it since they have long ago made up what they try to pass off as minds. Can you imagine someone telling you that he has over 6,000 miles on a set of disk pads? Of course he must be leaving out that he doesn't live in hill country. In one year I had to change the disks twice on the HiFi. It had grooved so badly that it was eating pads.
09-17-18, 08:57 AM
#58
Non omnino gravis
I also see that they do not understand the effects that a reservoir on disk brakes has in a non-powered set-up. I could explain it to them but I think I will leave them to not-ponder it since they have long ago made up what they try to pass off as minds. Can you imagine someone telling you that he has over 6,000 miles on a set of disk pads? Of course he must be leaving out that he doesn't live in hill country. In one year I had to change the disks twice on the HiFi. It had grooved so badly that it was eating pads.
And let's see, I've got a bit more than 300,000ft of ascent this year, haven't had to change the brake pads on anything. Probably because I don't see the need to descend with my hands on the brakes all the time.
Last time I changed a rotor? The rear 160mm IceTech was swapped out with 17,209 miles on it in December of 2016. The current rear rotor has... 11,684 miles on it.
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09-17-18, 09:04 AM
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Oh, gems like "Disk brake pads wear out rapidly. Unlike a car there is no fluid reservoir and no power assist so the entire brake operates with manual high ratio lever pull. This means that it doesn't require much wear before the lever bottoms out. The only way to "adjust" this is to replace the disk pad." I mean, that's not even true of entry-level mechanical calipers. It's certainly not true of hydraulic.
09-17-18, 09:32 AM
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I also find it pretty face-palm funny that you did not realize you could adjust for pad wear on mechanicals. No wonder you go through so many pads.
09-17-18, 09:39 AM
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I think that the figures of bicycle injuries are that 90% of them are caused because the rider cannot remove his feet from the clip-ons fast enough.
09-17-18, 09:50 AM
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+1 and two counter points:
a). I have disks because I don't have to clean the rims every weekend; I can if I want to, but I don't have to [in order to keep effective *********** and rim wear].
b). I think disks are here to stay. Someone mentioned above that after some years, only cheaper bikes will have rim brakes and that we are in a transition period the same the MTB world was back when.
Another point: someone else mentioned further up that if the UCI removed weight limits, disk brakes would instantly become a thing of the past. Yes, agreed to this.
a). I have disks because I don't have to clean the rims every weekend; I can if I want to, but I don't have to [in order to keep effective *********** and rim wear].
b). I think disks are here to stay. Someone mentioned above that after some years, only cheaper bikes will have rim brakes and that we are in a transition period the same the MTB world was back when.
Another point: someone else mentioned further up that if the UCI removed weight limits, disk brakes would instantly become a thing of the past. Yes, agreed to this.
Yesterday as I was riding my Colnago along a bike lane some SOB in an SUV decided that he could get to the corner faster in the bike/parking lane rather than waiting the 5 seconds for the light to change. I still can't understand how he missed me but it couldn't have been by more than an inch. The odd thing is that this is another town 10 miles from me and this same SOB did exactly the same thing only not as close a couple of years ago. Apparently he will never learn. So I will remain on the lookout for large gold SUV;s for the remainder of my life, Certainly a more powerful brake would have had absolutely no effect save stopping me directly in his path. Swerving and possibly accelerating were the answers. THEN stopping and cussing that guy out. I immediately recognized him by the "oops" hand sign that he made on both occasions.
09-17-18, 09:54 AM
#63
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Of course you can't. Like most jr G-men you have the idea that the more that agree with you the more proof you have of being correct. Well, sorry, you're wrong. Especially some guy saying that he is getting 6,000 miles on brake pads.
09-17-18, 10:03 AM
#64
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Oh, gems like "Disk brake pads wear out rapidly. Unlike a car there is no fluid reservoir and no power assist so the entire brake operates with manual high ratio lever pull. This means that it doesn't require much wear before the lever bottoms out. The only way to "adjust" this is to replace the disk pad." I mean, that's not even true of entry-level mechanical calipers. It's certainly not true of hydraulic.
The reservoir does exactly what you think it doesn't do-- it holds the brake fluid needed to fill the calipers as the pistons extend to accommodate pad wear. Just like the fluid reservoir on every other vehicle with hydraulic brakes.
And let's see, I've got a bit more than 300,000ft of ascent this year, haven't had to change the brake pads on anything. Probably because I don't see the need to descend with my hands on the brakes all the time.
Last time I changed a rotor? The rear 160mm IceTech was swapped out with 17,209 miles on it in December of 2016. The current rear rotor has... 11,684 miles on it.
The reservoir does exactly what you think it doesn't do-- it holds the brake fluid needed to fill the calipers as the pistons extend to accommodate pad wear. Just like the fluid reservoir on every other vehicle with hydraulic brakes.
And let's see, I've got a bit more than 300,000ft of ascent this year, haven't had to change the brake pads on anything. Probably because I don't see the need to descend with my hands on the brakes all the time.
Last time I changed a rotor? The rear 160mm IceTech was swapped out with 17,209 miles on it in December of 2016. The current rear rotor has... 11,684 miles on it.
Not that your choice of brake in those conditions is any of my business but then it shouldn't be your business to be pushing disk brakes in a string where the originator was wondering why most pro racers aren't using disks.
09-17-18, 10:06 AM
#65
Senior Member
Apparently 1. You are not a bike mechanic if you have the idea that there is a hydraulic fluid reservoir on bicycle disk brakes. 2. The SELLING point of hydraulic over manual is smoother application and less mechanical losses. Can you please stop with your dumb postings that because they are worthwhile on an MTB that they MUST be worthwhile on a road bike? Aside from MTB's being much heavier than road bikes, the suspension forks are designed to withstand immense bending forces. This is not something that is necessary on a road bike. As someone else stated, if the UCI dropped their weight limit you would never see another disk brake on a racing bike.
There are reservoirs on Open System disc brake systems.
Closed systems do not have a reservoir.
https://www.sram.com/sites/default/f..._brake_v06.pdf
https://www.parktool.com/blog/repair...and-adjustment
09-17-18, 10:08 AM
#66
Senior Member
No, I really would like to see you explain how the reservoir on a bicycle hydraulic system works.... that is, if you now believe they even exist.
I also find it pretty face-palm funny that you did not realize you could adjust for pad wear on mechanicals. No wonder you go through so many pads.
I also find it pretty face-palm funny that you did not realize you could adjust for pad wear on mechanicals. No wonder you go through so many pads.
https://www.sram.com/sites/default/f..._brake_v06.pdf
What amazes me is people still making broad statements without even checking Google for 10 seconds to see if they are right.
09-17-18, 10:16 AM
#67
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A couple of 4000 ft drops from Mt Wilson, some of it 20%. Also 15-20% grades on the road. If the rear rotor needs replacing I'm going with 203 in the rear.
Possibly semi-metallic pads, but they are 3 times the price. Brakes stop good no problem, good modulation, I can lock them any time... I like them, but...?
09-17-18, 10:20 AM
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Just curious....
Especially some guy saying that he is getting 6,000 miles on brake pads
Last edited by Kapusta; 09-17-18 at 11:51 AM.
09-17-18, 10:31 AM
#69
Non omnino gravis
30,000 ft of climbing isn't a lot of climbing but never-the-less if you say you don't use your brakes of what use are disks even if they work slightly better in the rain? If your descents allow you not to brake then I wouldn't be surprised that you have long life but the miles you are quoting give me the idea that the vast majority of your riding is as a commuter. So what do you care what sort of brake you have one your bike?
Still waiting for an engineer’s explanation as to how my brakes are staying adjusted as according to you they don’t do that.
I have a light, rim-brake bike, and a heavy disc brake bike. The heavy one brakes better. But the rim brakes work just fine. I only showed up in this thread because there’s nonsense swirling around. I’m drawn to it.
09-17-18, 10:36 AM
#70
Senior Member
Are you seriously still contending that there is no fluid reservoir for hydro brakes on bikes? Does the fact that this majority opinion that they exist is shared by the companies who make the disc brakes, and all of us who have actually bled brakes and seen the reservoirs for ourselves?
Just curious....
Just curious....
09-17-18, 10:38 AM
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So ... he had hydraulic disc brakes and never knew there was a fluid reservoir.
No wonder he doesn't like discs.
No wonder he doesn't like discs.
09-17-18, 11:24 AM
#72
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Probably.
I've definitely increased the lifespan of mine as I increased confidence and recovered from an injury (which my ankle surgeon cheerfully suggested created a lot of scar tissue between my ears).
I've definitely increased the lifespan of mine as I increased confidence and recovered from an injury (which my ankle surgeon cheerfully suggested created a lot of scar tissue between my ears).
09-17-18, 12:00 PM
#73
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In any case .... pad wear is not endemic to disc breaks, but to bicycle brakes. Some riders in the Pacific Northwest regularly go through Rims in a couple seasons, and brake pads .... don't ask. In Flatahoma, i can ride the same brake pads (on a road bike) for nearly forever. The MTB gets ridden less since my last injury, but its brakes get used a Lot more per mile. even so ... it is not because the product sucks, but because the product works. if the brakes didn't stop the bike I would be in a wheelchair and talking about wheelchair brakes. Brakes, like tires, get used up more quickly when they are used harder.
Or at least, that is how it seems to me ... but what do I know? i am not an engineer.
@cyclingtom ... you did mean the guy who drives the train, right?
Or at least, that is how it seems to me ... but what do I know? i am not an engineer.
@cyclingtom ... you did mean the guy who drives the train, right?
09-17-18, 12:11 PM
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-Matt
09-17-18, 12:38 PM
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Yep. Here is another variable: Being a big city dweller. When I commute on my LHT, I am usually hitting my brakes every 500', if not less, thanks to lights and stop signs. Between that and three or four loaded tours, I am lucky to get much more than a year out of my brake pads. All the starting and stopping also wears the chain faster.