17

Let me start the question by saying that I have a pretty good impression of the advantages of disk brakes vs. V-brakes, so I'm not asking about performance comparisons.

I'm MTB-ing several thousand kilometers per year, and most of those are on the mountainside, where I have nice climbings, but also nice downhills (honestly I don't know which I like best). The thing is that I currently have a V-brake equipped bicycle, however for performance/safety reasons I'm strongly considering moving to hydraulic disk brakes.

But, on the other side, I also try to be as environmentally friendly as possible, this is why I rarely change the consumables of my bike, even if overly-used ones make it difficult to ride smoothly.

Before I switch to hydraulic disk brakes (I'm not currently taking into consideration the cable disc ones), I'd like to find out if they are more environmentally friendly than the V-brakes, or not.

V-brakes:

  • use some kind of hard rubber/plastic, not sure how degradable are the molecules that get ripped while braking
  • they also wear out rims, from my experience I need to change them after 10.000km
  • the cables don't degrade that easily (at least compared to the shifter ones), I currently use ones bought 20 years ago and they are still in 100% shape
  • the cable housings also don't need to be changed often, I usually oil them and gain one more year of easy braking

Disk-brakes:

  • need an extra disk, which poses an initial environment impact
  • the mineral oil should not have an environmental impact, right, as it's mineral
  • the brake pads wear out after a while, I assume they are made of metal, so they should have a less environmental impact than the rubber/plastic from V-brakes
  • the disk also wears out after a while, however, that's still metal, which should be recyclable
  • zero impact on the rims!!!

Is my evaluation correct? Did I miss something?

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    @Cristik: Ok, so - perhaps you should add these to the question. Maybe they're more environmentally friendly than the other kinds?
    – einpoklum
    Mar 29 at 8:43
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    @einpoklum currently I'm on V-brakes and considering switching to disk brakes, thus only need to find out if disk brakes are more environmentally friendlier or not. This is not a question about comparing all types of brakes from an environmental impact aspect.
    – Cristik
    Mar 29 at 8:46
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    @Peter-ReinstateMonica yes, they are from the former bike I had, I changed bikes about 12 years ago :)
    – Cristik
    Mar 29 at 11:28
  • 3
    @Griffin So did I in my first comment. However, I believe that Cristik might feel a little irritated at us derailing the comment discussion like this. I think it's good that there is a good, general reminder about addressing the big issues first, but I also think we should not give in to the temptation to thoroughly discuss the details of minor gains here. Whoever has something to say on the environmental impact of bike brakes, is welcome to post an answer. But discussing the environmental impact of viewing this site is outside the scope for comments on this question, imho. Mar 29 at 13:19
  • 3
    @mattnz But look at the bright side: if disk brakes are more dangerous, they might just kill a few evil polluting humans, the removal of which from Earth would be a net positive environmental impact. ;-) Mar 30 at 15:21

9 Answers 9

18

We can assume that V-brake pads are essentially non-degradable. The same is true for resin disc pads. But are non-recyclable. Metal disc pads seem to be various copper alloys which are probably OK in the environment in such tiny quantities, especially as they'll oxidise, and should be recyclable as scrap metal. There are also ceramic pads form which the dust should be comparable to stone dust - I won;t use them again after they contributed to a bad experience; they also increase rotor wear.

Rims shed aluminium, and discs shed steel, both in tiny quantities; these are probably equivalent.

Rotors last quite a long time and are recyclable. Cable inners are similarly recyclable, outers less so (the plastic coating probably ends up burnt if you treat the housings as scrap metal).

You say the mineral oil should not have an environmental impact, right, as it's mineral but that isn't true. Spilt oil is quite polluting at the surface. You shouldn't ever spill any in the wilds, but if you change your oil it will probably end up in landfill, soaked into rags or in a small container; that's also true from bleeding though in smaller quantities. Some disc brakes use DOT fluid - don't swap or mix brakes fluids as they're not compatible. DOT fluid is based on polyglycol ether and is also something you wouldn't want to release into nature.

So on pad materials, metal pads on disc brakes win, but on pollution potential and disposal of other consumables, cable brakes probably win. I say cable brakes there, and not V brakes, because cable discs are probably the best all-round option for you. I run BB5s on one of my bikes (a tourer that I treat as a gravel bike), and seriously considered those or some other cable discs for my MTB*. If you're happy to run V brakes, cable discs will be at least as good, slightly better in the wet, except for the very worst ones. My comparison is with a hybrid that again I take off-road, with V-brakes and the best pads I can find.

So cable discs, that you dismissed, would work out best overall (with metal or ceramic pads).

Aside from local pollution, manufacture and shipping have an impact from energy and materials use. To a first approximation you can consider the lifetime mass used up, but note that manufacturing aluminium is far more energy intense than steel, so rotors would beat rims.

*in the end I went for an upgrade to the poor quality hydraulics it came with.

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    Thanks for the details, I imagined that since the brake oil is mineral oil, it has less impact on the environment. I was "fooled" by the "mineral" term :)
    – Cristik
    Mar 28 at 17:57
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    "Mineral" oil is actually a very old name for certain kinds of petroleum oils. It was called mineral oil because it came from the ground, as opposed to animal oils, or vegetable oils. Also, for the record, modern highly refined mineral oil is actually fairly harmless compared to many other petroleum products, certainly a lot safer than motor oil, fuel, or hydraulic fluid.
    – barbecue
    Mar 29 at 1:49
  • 1
    @barbecue it can even be consumed in small quantities, though it's a laxative. Even clean it's not good for soil though
    – Chris H
    Mar 29 at 7:00
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    I like to call aluminum “solid electricity”. The stuff requires crazy amounts of energy to extract from bauxite, and still quite a bit to recycle.
    – MaplePanda
    Mar 29 at 7:08
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    @MaplePanda ... plus the environmental nightmare that is the red mud produced alongside the aluminum (en.wikipedia.org/wiki/Red_mud). Mar 29 at 7:26
12

The world is full of perfectly good cantis, v-brakes, and rim brake wheels that sit unused since disc has taken over. Using what we've already produced for its actual full service life is pretty hard to beat for environmental impact in this and many other cases. Making metal things has a large environmental impact.

Consider also that you could procure some hydros that are being trashed or sitting unused because there's something wrong with them that's not considered monetarily viable to fix, like needing a seal overhaul with parts that aren't readily available, but you might be able to do some make-2-good-ones-from-4-bad-ones tricks on.

If you were comparing in a vacuum, i.e. you had to buy either system new, you cannot divorce that question from your projection of how many rims you think you're going to go through over the life of either system. From there you need to think about what your habits are in terms of wearing through rims from braking if you use rim brakes. But, one of the major considerations is also even if you go to discs, whether your rims will die by violence before the wear-saving effect of disc brakes would amount to anything anyway. For many mountain bikers the answer is yes and the rim wear point is basically moot, but maybe not if you're a casual rider (unlikely to damage a rim by impact) and/or heavy braker and/or ride in conditions that are particularly hard on rims used with rim brakes.

5
  • Very good point, didn't think about this aspect of environmental impact of brakes already produced.
    – Cristik
    Mar 29 at 6:48
  • Question is, in the long run, I wanted to know which of the consumables of V/disk brakes have a larger impact: cables+housing+rubber pads+aluminum rims for V-Brakes, or housing+mineral oil+pads+disk for disk brakes
    – Cristik
    Mar 29 at 8:55
  • Some good points. I'm fixing up an errand bike from bits of 3 or 4 bikes at the moment (probably canti brakes front, V rear). I'm wary of the failure modes of hydraulics of unknown provenance but someone more used to stressing them could do well there
    – Chris H
    Mar 29 at 14:24
  • @Cristik To answer that you really have to get to a premise on your own of how likely it is for the kind of riding you do that brake track wear will actually be the constraining factor on whether it's time for a new rim. If you're mountain biking then usually it won't be. Mar 29 at 18:39
  • But if for your riding style, if going to discs actually saves you the consumption of multiple rims, I think that blows all the other considerations away in terms of environmental impact. Look seriously at things like mining and power consumption from making metal stuff. The fact that it's an easily recyclable material doesn't matter because we're still mining it and so displacing the consumption still counts in full. Mar 29 at 18:53
11

The true answer is: It really doesn't matter. You are riding a bicycle, that is what matters. If you are truly eager to minimize your ecological footprint, caring about the break type on your bike is wasting precious resources better employed elsewhere.

As an example, if you are concerned about micro plastic coming off brake pads: Stop wearing the "functional" synthetic bike clothes which release orders of magnitude more micro plastic into the environment with each wash cycle. And so on. Of course you are probably already wearing Merino, but that was only an example: Almost every even very innocent-looking aspect of your life will have an orders of magnitude larger ecological impact than your bicycle brakes.

3
  • The dilemma began when I started considering switching to disc brakes, I know the disc brakes perform better in most cases, but before investing time and money in the switch I was also curious if I'd better stay on V-brakes, if they have a smaller environmental impact.
    – Cristik
    Mar 29 at 11:27
  • @Cristik given that, hydraulic disc brakes would need new levers, while cable ones wouldn't (I'd still fit new cables though)
    – Chris H
    Mar 29 at 14:26
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    +1 This is the only correct answer. We all have low-hanging fruit on our ecological footprint tree and bicycle brakes are not among them. Not even close. Unless OP is living off the land in a utopian ecological commune and does not interact with the developed world at all except to buy bicycle brakes.... then maybe. For anyone that isn't wearing grass for clothes and uses some form of currency to procure goods then there are far more productive ways to cut down on their ecological footprint.
    – J...
    Mar 31 at 18:50
3

V-brakes with good pads are probably better from environmental standpoint due to the slow wear rates of pads and rims compared to the wear rates of disc pads and disc rotors. Besides, disc brakes often use resin pads and I don't believe the resin is any better than rubber for the environment when worn away. Anyway, your tire wear rate far exceeds your brake pad wear rate, so in any case, if you're worried about brake pad rubber you should be worried about tire rubber.

Good V brake pads (such Kool Stop Salmon) last easily over 10 000 km in dry conditions. Rims probably last several times that, 50 000 km - 100 000 km in dry conditions. When wet, both pad and rim lifetime suffers but in varying conditions I would be very surprised if a good pad leads to shorter rim life than 20 000 km. Of course if your "varying" means mountain downhill in rain only, then you can wear rims in as little as 2000 km.

Resin pads in disc brakes in dry conditions last 2000 km, about tenth of that of good V brake pads. Discs last about six pads, or 12000 km, less than rims, but they are somewhat lighterweight too (about third of rim weight). In wet conditions these are probably not as severely reduced as with V brakes. Metal pads could improve pad lifetime at the cost of disc lifetime, not sure if this is a good or bad tradeoff.

I suspect if you have been getting 10 000 km rim lifetime that you are riding in varying conditions including wet, and you are not using Kool Stop Salmon pads. It's time to switch your pad brand! Good pads make a lot of difference especially when wet. The Salmon color is due to iron oxide in the compound, and without that color you can't have good pads.

Also as you correctly noted, mineral oil has an environmental impact too.

On the other hand, which is better for whoever pays for bike maintenance, the answer is disc brakes since rim replacement has high labor costs.

Also for the rider in the wet disc brakes are far better because of the consistent performance and no lag.

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    There is really no need to push these specific products all over the site so heavily. Formulations like "(such Kool Stop Salmon)" are fine, but saying that "you are not using Kool Stop Salmon pads. It's time to switch your pad brand!" is way too strong. There are other good pads. Mar 28 at 16:42
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    Also, both resin pads and rotors can last more than what you indicate. Mar 28 at 16:43
  • Yeah, I made poor/very poor estimations about the mountain roads I take, and I often end up biking in mud or wet conditions. So if I improve this factor I will also improve the lifetime of my rims, thus, making the V-brake more environmentally friendly.
    – Cristik
    Mar 28 at 17:59
  • if you're worried about brake pad rubber you should be worried about tire rubber - yes, but this is something I can't control much. I usually buy the best tires, and wear them until they have big cracks that make them very unsafe :)
    – Cristik
    Mar 28 at 18:00
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    I'm not aware of any other good pad than Kool Stop Salmon. The color is due to iron oxide. You can't have good pads that aren't colored by iron oxide because then you won't have iron oxide in the pad. Only Kool Stop makes these good pads.
    – juhist
    Mar 29 at 16:07
3

Safe way of riding has the most of the ecological impact. If you hit even not a human, or just have near pass somebody has seen, this promotes the view that bicycles are not safe enough for practical use. This may prevent somebody from switching into this way of transportation.

Due that I think it is better to use say lights in the night, even if they have ecological impact. If I ram into something in the midnight with no lights, somebody will say "what an idiots these cyclists are". This discourages others from using bicycle for commuting.

For the same reason, I think, disk brakes are more environmentally friendly, as they give more control on the bicycle, this way reduces the number of accidents, this way increases the popularity of cycling. I have disk brakes on one bicycle and rim brakes on another and when I switch the bicycles I clearly see the difference. This way no brakes at all (I mean, a fixie) will do more ecological damage if you get into accident preventable by having a brake.

If you can maintain the rim brakes so that they are equally efficient, this answer does not apply to you.

1
  • Given the massive cost of recovering from injury, (time, pain, effort) anything like lights that decrease the chance of accident are worth it. Low likelyhood, extremely high cost events should be avoided at all costs. Just use your lights even in daytime.
    – Criggie
    Apr 1 at 23:10
3

The differences depend so much on actual conditions that the far bigger contribution to environment friendliness is riding bike at all. So don't care about consumables on a bicycle. They are neglectable compared to any other means of transport.

Use a bicycle whenever possible - that's it.

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    Well... I already use a bike, and I bike a lot, for both practical and recreational purposes :) So the next thing on my list is what can I do for my current bike to make it even more environmentally friendly. I do get your point though, that it's hard to estimate which kind of brakes are more friendly to the environment, as there are many factors involved.
    – Cristik
    Apr 1 at 11:25
-1

As a very rough estimate of the environment impact of anything, you can just use its price (including delivery for personal-use products and services).

I am chemist, I know what I am talking about.

Of course, some goods and services are engineered to lower their environmental impact that makes them more expensive, but the general case boils down to your spending.

If V-brakes are good for X kilometers and cost $xx and disk-brakes are good for Y km and cost $yy, you just divide $xx/X and $yy/Y and compare.

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    Is price/km a good rough estimate of the environmental impact though? I feel that due to choices in economic structure the monetary price of a product might be far from the "true" price of a product due to externalities passed on to the environment or other people. Mar 29 at 21:09
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    The pricing model sounded good in my head until I remembered about all those cheap synthetic shoes coming from China, costing $5, while real leather shoes cost 100x more, and are way more environmentally friendly.
    – Cristik
    Mar 30 at 14:13
  • On the other hand, as Meja well said, it’s all about the money :)
    – Cristik
    Mar 30 at 17:30
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    How sure are you about the environmental friendlyness of real leather shoes? I would guesstimate that leather, being an animal product and requiring a lot more processing before becoming a shoe, has a much higher environmental impact. Also, don't forget to divide the cost of each type of shoe by how long you can use them.
    – JanKanis
    Mar 31 at 13:34
  • @JanKanis depends on what factors you consider when evaluating the environmental impact. If you're considering solely the carbon footprint, this will not give you the full picture.
    – Cristik
    Mar 31 at 15:41
-2

This choice would make you feel like you did something, and that feels good.

Not riding would make you feel bad. It isn't an option because you like riding, and you can justify the use by pretending you made a environmentally friendly choice.

Thanks hero!

1
  • Welcome to the site, and thank you for your contribution. Please consider the be nice policy on Stackexchange before posting again. You can also read the tour and learn how SE works.
    – Criggie
    Mar 30 at 22:21
-2

First, brake fluid isn't mineral oil. You may use mineral oil in your lines but brake fluid is glycol based.

Second, you're only considering environmental impact at point of use. You're not taking into consideration production and transportation impact of your purchase.

Third, much like only considering environmental impact at point of use, you aren't considering the impact of your MTB activities. First, you're using the bike for recreation, not commuting. You're likely driving a vehicle unnecessarily to the location at which you like to MTB. Then, you're destroying habitat with your chosen recreational activity. You think those MTB trails are natural? You think they don't impact wildlife? That's not environmentally friendly. Third, your recreational activity required the production of a bicycle which created significant carbon emissions and excessive use of plastics, along with the safety gear you use.

In summation, your desire to help the environment by choosing more environmentally friendly brake pads is more than offset by your choice to partake in a destructive leisure activity.

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    I can see your point and I think it has some merit. But then again … we don’t have to achieve zero CO2 emissions or zero environmental impact. Getting below 3t CO2e per year per person is enough. If you don’t need two sets of new wheels per yer (either by not riding or by choosing different components) this can help to achieve that goal.
    – Michael
    Mar 30 at 14:45
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    Not everyone travels to the point of origin by a vehicle. I almost always just cycle from my home. Much less often, I take the train somewhere. But I can agree that the brake system choice is a relatively minor point overall. Mar 30 at 15:06
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    First third of answer is ok, but the rest feels like a rant towards cyclists. Btw, did you know that I use a bike assembled in 2006, some parts dating 2003? And that I use this bike for commuting also? Or that I live 15km away from the mountain so I don’t have to use a car to get to my starting point? Or that I mostly use mountain roads already used by the (isolated) people living in the area?
    – Cristik
    Mar 30 at 17:05
  • Some hydraulic brakes use mineral oil, some use brake fluid, some use proprietary fluids like Magura.
    – Criggie
    Mar 30 at 21:23
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    Welcome to the site - do please take a moment to read the tour and learn how the site is set up - as a Q&A each answer has to at-least address the question. This is more or a reply that is related to the topic but tangential. You do raise some excellent points, but no part of this specifically answers OP's question about V brakes vs Hydraulic disks. I'd be tempted to make the "it doesn't matter which brake you choose because..." message a bit more clear.
    – Criggie
    Mar 30 at 21:26

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