Touring - Why are disc brakes bad?

Can someone explain to me why discs are bad when they are so good? Does anyone who's against discs on a touring bike have any anecdotal advice? I'd like to hear about your negative experience with discs on tour that caused you to switch back to cantilevers.

Disc's aren't bad. Their modulation and smoothness are great. I was astounded by their smooth, sure stopping power. I just don't prefer them.

They weigh more.
They're down there around the axel and can get in the way. You have to work around them.
It's something else I'd have to learn how to fix. I know canti's, vee's and calipers.
More parts.
I'm given to understand that they apply different forces/stresses on the wheel—spokes in particular. Someone else who understands that aspect better can fill you in. Cyccommute, I believe, gave a rational explanation.

Anyway, those reasons won't hold water for a lot of folks and that's all right. As I said—it's personal preference. As most things are. I don't think they're bad at all, I just don't prefer them. It's mostly about the weight and added complexity for me.

There have been some issues with disc brakes, some of which I have only heard about, others which I have seen for myself:

1. Anecdotal: They are very strong, and so if you brake too hard with the front brake, you risk going over the handlebars. I don't know how true this is, but I think I've read it on occasion.
2. Anecdotal: The front disc brake puts a lot of tortion stress on the wheel, which tends to pull it out of the dropout, thus producing the possibility of a catastrophic crash on bikes with quick release hubs that haven't been tightened properly. I don't know if this is still an issue, since all front forks now seem to have "lawyer lips" which prevent the wheel from disengaging unless the quick release is manually loosened.
3. Anecdotal: Fork stress. The tortion causes stresses to be put on the fork, which could cause handling problems or even failure. Some bike makers (e.g. Tout Terrain) make forks specially strengthened to compensate.
4. Personal experience: Clearances can be complicated for mounting racks and kickstands. The disc brake housing tends to go just where you want to be attaching these things. For example, I cannot put a standard rear rack on my Novara Safari because of the disc brake mount position and housing; also, I cannot mount my favorite kickstand, the Greenfield.
5. Debatable: Complexity, and less availability of parts abroad, since disc brakes are relatively newer than the classic cantis.

Having said all that, there are benefits to disc brakes:

1. They are indeed very strong! Good for stopping a loaded bicycle on steep downhills.
2. Less risk of blowing out your tires on long descents because of heated up rims
3. Less wear on your rims, thus lengthening their useful life
4. If your rim goes out of true, then it doesn't affect braking
5. You could, on bikes with enough clearance, use either 700C or 26" wheels.
6. Disc brake pads tend to last a lot longer than rim brake pads
7. Better braking in the wet, and less clogging in muddy or snowy conditions

I guess there are pros and cons to any system; it depends on what is important to you and what you're willing to put up with.

Neil

They aren't bad, I love mine. I toured from Alaska to Panama on disc brakes. You just have to know how to adjust them because occasionally they misalign and cause an annoying 'brushing' sound.
The biggest downside of them is that if they break, parts are hard to find for them in remote areas, but overall I love mine.
They stop me down the steepest hills in any type of condition.

We had them on the triple - three people on a fully loaded bike = heavy and hard to stop. That being said - they were a pain in the rear. Every time we had a flat tire we had to unhook it and then hook it up again - which was a bit of apain. Would we do it again? In a heartbeat. Would I put them on a hot-so-heavy single bike? Probably not.

Oh wait - we had a DRUM brake, not a disc. Never mind what I said above...

It would clarify the issue to use a more specific category, rather than the broad category of 'disc brakes.'

There are significant differences among the different companies and models.

These include some major differences in reliability and durability, ease of adjustment, soundness of design and engineering, feel and modulation, quality of construction, simplicity/complexity, frequency of maintenance and repairs, and mtbf, among others.

Some are easier to learn about and easier to service.

One significant drawback is that many of the bikes used for touring don't have the lugs required to fit disc brakes either on the fork or the rear left dropout.

I have just acquired my first-ever pair of disc brakes for an MTB project, and pair of Hayes MX1 with cable actuation. I have the fork to fit them, but now I am perplexed by the fact that the frame (yes, another dump retrieval, but an OK one) doesn't have the rear lugs, and I am looking at acquiring a new frame that does. But then I could just go with V-brakes on the rear. Decisions, decisions...

Having just set up the front hub on the fork, I found the adjustment to get pad clearance to be extremely simple. As to on-the-road adjustment to avoid rubbing... well, I don't think it would be any more difficult. Adjustment of hydaulic calipers might be different.

Carrying two or three pairs of replacement pads also would be nothing compared with pads for cartridges for any rim brake.

The benefits were outlined well by Neil. I think that as far as the problems go, you only have to look at the experience of the MTBer. The drop-out issues were major ones, I think, when poorly designed forks were placed on the market. But they have been redesigned, I believe, so the leverages on the axle won't pull the wheel off. Looking at my Magura Odur, the drop-out itself has a different angle, there are lips around the dropout, and the caliper mounting tabs obviously are placed behind the leg. Of course, the through-bolt system has now been adopted to make absolutely sure wheels won't come off.

The issues of torsional stress on the spokes I don't see as valid when compared with the stresses of normal riding uphill in very low gears with a heavy load. As to stress on the hub and bearings, that might be a different issue.

The only major drawback I can see is damage or distortion to the rotor caused by a fall against a object.

Can someone explain to me why discs are bad when they are so good?

Part of this is inertia.

Often when something new arrives on the scene, there is some period of lag time. There is some prejudice or doubt, some habit or attachment to tradition.

This seems to happen in many fields. Touring is one of them.

There are other aspects of touring bikes that also suffer from this.

Also, early versions tend to have bugs. Even long after the bugs have been worked out, rumors and residual attitudes tend to linger.

I'd like to hear about your negative experience with discs on tour that caused you to switch back to cantilevers.

Some models have problems staying in proper adjustment. They can make very annoying sounds.

Some people just give up and turn back.

Also, early versions tend to have bugs. Even long after the bugs have been worked out, rumors and residual attitudes tend to linger.

I use Shimano M-475 (Deore) Cable Discs on my bike,with Shimano Deore Vee-Brake levers.I carry an extra caliber,cable and two sets of spare pads,Cheap,VERY Effective,Bombproof...Sorry,but I will never go back to rim brakes...Ever!!!

Can someone explain to me why discs are bad when they are so good?

Many touring bikes just are not set up to accommodate them.

Many people stay with what they have.

There isn't much demand for touring bikes period (compared with other segments of the bike market), and there is even less demand for touring bikes with disc brakes (for various reasons, some of which are mentioned above).

Sheldon Brown has said that eventually discs will overcome and predominate.

It takes some years though.

Can someone explain to me why discs are bad when they are so good?

Peter White talked me out of disc brakes. He said that good, properly adjusted cantilevers do just fine. Yes, [some] disc brakes are 'stronger': but that is meaningless [according to PW, in that conversation] because if the cantis can freeze the wheels, you can't do any better than that.

Even in the rain, I wondered.

Yes, he said.

He talked about his own bike, and how he could lock the wheels under any conditions, including mud.

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[I remained somewhat skeptical, but this was his way of seeing it.... He thought that discs were just expensive and unnecessary, even on tandems.]

[He also seemed to think that most people do not get the most out of their cantis.]

I have disc brakes on some of my bikes, cantis on some and road bike calipers on a couple. I don't really think any of these systems is perfect for every application. My touring bikes have v-brakes and I have no issues with stopping power rain or shine. I don't overheat my rims in the mtns.

I use v-brakes because:
- allows you to use a fork with vertical compliance to absorb road vibration
- inexpensive $25 a pair
- lots of stopping power
- modulate well
- easy to adjust
- easy to get parts for
- light
- simple
- easy to repair
- doesn't require dish in front wheel and less dish on rear than disc
- not easily damaged during transport

Disc brakes do have some advantages:
- better in all weather, especially winter & mud
- better for really heavy loads as you can get bigger discs [however - you need an appropriately strong fork/frame or all you do is damage your bike under severe braking]

However, there is no magic bullet and unless you are riding an Xtracycle hauling a ton or winter commuting or off road touring down muddy tracks I don't think they add much value to your bike while making it much less likely to be repairable internationally.

One often quoted reason to get discs is to avoid over heating rims. First off read this article (http://www.talu.com/brakes.php) and appreciate your discs only have a finite heat capacity before they are damaged. Second consider that you may be using your brakes poorly. Applying the brakes constantly for a long duration is a recipe for disaster. Shorter stronger applications allow your discs and rims to cool down in the air flow. You can validate this yourself. Go down the same long hill twice apply your brakes lightly, but consistently the whole way down to keep a constant speed. Then try the same hill again and keep the same approximate speed by applying your brakes strongly and then letting them off for a bit - repeat. Check the rims at the bottom - which are warmer.

Quote from the article I linked to above - it talks about tandems, but a heavily loaded touring bike has the same issues:

"Tandemists who are using the current crop of mountain bike disc brakes on their tandem should keep in mind that none of the current disc brakes are designed for tandem use. All of the current disc rotors are too small and light for tandem loads on big hills with heavy teams. Some of the rotors are too light even for light teams on medium hills. In the right conditions, the rotor will overheat too quickly because of its low mass (and therefore low capacity to absorb braking heat).

Certain people are successfully using existing single-bike disc brakes on tandems, without risk of brake failure. Those people ride in flat places with no big hills. The next question those people may wish to ask themselves is why they have bothered with the expense, complexity and extra weight of disc brakes when rim brakes would have offered perfectly adequate performance.

Rim brakes on a 700c or 26" wheel have a mechanical advantage over a typical 8" disc brake because the radius of the braking surface is much smaller on a disc rotor than on the wheel rim. Much more braking power can be applied with the rim brake (about 10 times more, thanks to the miracle of leverage)."

I'm not suggesting disc brakes are bad or they should not be used. However, there seems to be a very simplistic view of how brakes perform that suggests discs are better than a canti brake without factual basis for this argument.

One of the furphies about rim brakes is their ease of setting up. Sheldon Brown has some interesting things to say about mechanical advantage and being able to get the most efficiency from cantis. Most people aren't aware of these issues and blythely adjust their brakes anyway.

There are issues with straddle cable length and others such as such as toe-in related to brake squeal. And the fundamental design parameters of various canti and V brakes can influence stopping efficiency. Just getting the pads aligned correctly on the rim can be a challenge. V brakes don't escape criticism here, either, if you run standard STI braking systems -- setting up a Travel Agent can be an interesting exercise, too.

Having just set up a disc brake on the bench... well it was just soooooo easy. The proof will be in the riding, of course.

But a critical factor not really highlighted yet in this discussion is the longevity of rims. Take the pad quality of V and canti brakes. Shimano pads are renowned for being very abrasive on rims. Koolstops have a reputation for being relatively gentle, but I have worn a Velocity Aerohead front wheel to a point of concern.

Most importantly, there are the conditions, and I am not talking about braking efficiency here -- I am talking about if you ride in wet, gritty conditions that will wear away the rim wall rapidly. A (real) advantage of disc brakes is that they rotate away from crud on the road, and are less prone to wear because they don't pick up the grit so much. Plus, you don't have horrible grey masses of fine brake dust oozing all over your rims, tyres, frame and clothing.

I am interested comments from long-term users of both types of brakes as to how long their rotors and their rims last under the respective systems in similar riding conditions.

I am not sure, also, that it is entirely fair to compare the efficiency of either brake by using tandems as the basis. No touring bike is going to be ridden with another person plus luggage on board, as well as the extra mass of the frame. The issues of overheating might be real in very very tortuous conditions, but why do not the same principles of cadence braking (on-off-on-off) apply to disc brakes?

I went with mechanical discs because of their simplicity in set-up and adjustment. I have dealt with hydraulics in other automotive arenas and they can be finickity if (a) your seals aren't totally sealed, (b) everything isn't totally (surgically) clean when servicing and (c) you don't use alcohol to clean the system (there are others, but that's a start). Above all, it's much easier to replace a broken or bent cable than it is to source a new hydraulic hose and the associated paraphenalia to connect it (which also could be read as a positive for rim brakes).

It's also worth pointing out that rim brakes are in fact disc brakes in of themselves.

Can someone explain to me why discs are bad when they are so good?

From another perspective, they are bad because they can lead to liability problems.

Many bike manufacturers pay attention to potential liability issues.

Disc brakes have had some unexpected consequences that have led to lawsuits.

The QR is initially restrained by the retention lip on the fork (assuming it is present), however over time the slipping of the quick release leads it to unscrew, which is described here. Once it has unscrewed enough, it can be forced over the retention lip and the rider will crash.

Some further discussion of these and related issues here:

http://www.ne.jp/asahi/julesandjames/home/disk_and_quick_release/

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In addition to the liability issues, there are the safety issues.

'The QR is initially restrained by the retention lip on the fork (assuming it is present), however over time the slipping of the quick release leads it to unscrew, which is described here. Once it has unscrewed enough, it can be forced over the retention lip and the rider will crash....'

So even with a retention lip there can be problems, and I would respectfully disagree with


...The front disc brake puts a lot of tortion stress on the wheel, which tends to pull it out of the dropout, thus producing the possibility of a catastrophic crash on bikes with quick release hubs that haven't been tightened properly.....
and

...since all front forks now seem to have "lawyer lips" which prevent the wheel from disengaging unless the quick release is manually loosened.....
which isn't always the case.

The advantages of ceramic rims may be relevant to consider. Among other things, they allow rim brakes to be used in abrasive (muddy, gritty...) conditions without rapid rim wear. They also tend to be better in wet conditions, with some brake setups at least.

Under similar conditions of use, they last much longer than standard rims.

[They do tend to wear out brake pads more quickly, even though the pads are much harder and more resistant to wear than the pads used with non-ceramic rims.]

Riding ANY bike with ANY equipment can lead to liability issues. I have seen MANY riders with rim brakes who didn't have a clue about doing up QRs and wondered why their bikes handles like rubbish. In one case, the non-disc-brake suspension fork on a hire bike of mine was damaged severely in an incident just like this. It was entirely operator error for not reassembling the bike as instructed after they travelled by motor vehicle to their ride venue.

The incident you point to is relatively old. The issue of fork design and particularly the placement of the mounting tabs for the calipers on the forks came to light in the early 2000s. I haven't seen many posts in the MTB forum here talking about lost front wheels since then. The two related design factors, as I remember the discussions at the time, were the angle of the dropout, particularly if they were vertical, and the tab position and the leverage or turning effect that created on the axle.

The advantages of ceramic rims may be relevant to consider. Among other things, they allow rim brakes to be used in abrasive (muddy, gritty...) conditions without rapid rim wear. They also tend to be better in wet conditions, with some brake setups at least.

[They do tend to wear out brake pads more quickly, even though the pads are much harder and more resistant to wear than the pads used with non-ceramic rims.]

You are talking from personal experience on this, of course?

Having just set up a disc brake on the bench... well it was just soooooo easy. The proof will be in the riding, of course.

But a critical factor not really highlighted yet in this discussion is the longevity of rims. Take the pad quality of V and canti brakes. Shimano pads are renowned for being very abrasive on rims. Koolstops have a reputation for being relatively gentle, but I have worn a Velocity Aerohead front wheel to a point of concern.

Most importantly, there are the conditions, and I am not talking about braking efficiency here -- I am talking about if you ride in wet, gritty conditions that will wear away the rim wall rapidly. A (real) advantage of disc brakes is that they rotate away from crud on the road, and are less prone to wear because they don't pick up the grit so much. Plus, you don't have horrible grey masses of fine brake dust oozing all over your rims, tyres, frame and clothing.

I am interested comments from long-term users of both types of brakes as to how long their rotors and their rims last under the respective systems in similar riding conditions.

I am not sure, also, that it is entirely fair to compare the efficiency of either brake by using tandems as the basis. No touring bike is going to be ridden with another person plus luggage on board, as well as the extra mass of the frame. The issues of overheating might be real in very very tortuous conditions, but why do not the same principles of cadence braking (on-off-on-off) apply to disc brakes?

I went with mechanical discs because of their simplicity in set-up and adjustment. I have dealt with hydraulics in other automotive arenas and they can be finickity if (a) your seals aren't totally sealed, (b) everything isn't totally (surgically) clean when servicing and (c) you don't use alcohol to clean the system (there are others, but that's a start). Above all, it's much easier to replace a broken or bent cable than it is to source a new hydraulic hose and the associated paraphenalia to connect it (which also could be read as a positive for rim brakes).

It's also worth pointing out that rim brakes are in fact disc brakes in of themselves.

I can mount and adjust either a set of v-brakes or a set of avid BB-7's in about the same time. Neither is particularly hard and both require some care and knowledge to get the best performance out of them. I've seen poorly adjusted discs and cantis.

Rim life will be better on a disc rim for sure, but what is better and does it matter? For a rainy/winter commuter or a tour through mud or really wet dirt roads I'd lean towards discs as they don't wear out your rims as fast. For just about anything else rim wear has never been a factor. This obviously depends a lot on the rider and situation - I've never been hard on brakes or rims - I can't explain why other people burn through pads/rims so fast???

I've gone through Avid BB-7 pads faster than I have kool stop v-brake pads. Not really a huge deal as both kinds of pads are small and light enough that carrying spares is a non-issue. I've not worn through a rotor yet.

I posted the tandem link as an example of the issues discs face during hard use. There was a German mtb bike magazine article that compared how much heat various braking systems could take before failure. The disc systems failed at around the same heat that rim brakes blew out tubes - unfortunately my link to that article no longer works. The problem with over heating IMO isn't the type of brake, but how it is used. I don't think a normal fully loaded touring bike should have brake overheating issues in the mountains with either rim brakes or disc brakes if used correctly, but I wanted to emphasize you can over heat and essentially destroy your rotor on a disc brake just like you can overheat a rim on a rim brake and blow out a tube.

All my discs are mechanical cable actuated. I don't trust hydraulics for a travel bike and for a bike I use in town I'd just as soon stick with cables as they are easy to work with. You might convince me to use a hydraulic disc for winter commuting. I have an original Avid disc brake - essentially a BB-7 which is 7 years old and going strong. I also have a new set of BB-7s and they both functional identically.

Riding ANY bike with ANY equipment can lead to liability issues. I have seen MANY riders with rim brakes who didn't have a clue about doing up QRs and wondered why their bikes handles like rubbish. In one case, the non-disc-brake suspension fork on a hire bike of mine was damaged severely in an incident just like this. It was entirely operator error for not reassembling the bike as instructed after they travelled by motor vehicle to their ride venue.

The incident you point to is relatively old. The issue of fork design and particularly the placement of the mounting tabs for the calipers on the forks came to light in the early 2000s. I haven't seen many posts in the MTB forum here talking about lost front wheels since then. The two related design factors, as I remember the discussions at the time, were the angle of the dropout, particularly if they were vertical, and the tab position and the leverage or turning effect that created on the axle.

It's still "the early 2000s" and this incident did not occur that long ago. There are still plenty of bikes being used that were from that time.

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"Riding any bike with any equipment can lead to liability issues" does not mean that disc brakes do not have their own set of concerns.

It's still "the early 2000s" and this incident did not occur that long ago. There are still plenty of bikes being used that were from that time.

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"Riding any bike with any equipment can lead to liability issues" does not mean that disc brakes do not have their own set of concerns.

The website you refer to says "Updated January 2006". That's now over two years ago. The links are circular and add nothing to the information. But knowing the way things move slowly in legal matters like this, I'd say the incident likely occurred in 2002 or 2003 at the latest.

And rather than having the option of using 1990s, 1980s, etc, just how do you want me to describe the first decade of what we are in? Read my reference to early 2000s and being early in this decade... which is well and truly past half way.

Brakes are the most troublesome part of the component search for touring bikes due to the difficulty of matching road levers to various styles of frame and long reach powerful brake. So whatever the faults of discs it isn't as though all the other options are easy in every case either.

Generally the discussion starts and ends with the cable actuated version of disc brakes. For better or worse there seems to be an agreement that a hydraulic brake systems on a touring bikes is too complicated for easy field service. Also, most touring bikes do not encounter the kind of mud that stops rim caliper brakes dead in their tracks. So two of the main advantages of "discs" die before we even start the discussion.

- Wheel separation issues should be dealt with, not used as an excuse for not mounting discs. I wouldn't by choice have quick releases on any touring bike. My mom's touring bike had a nice compromise, solid axles with butterfly nuts on them. Another option would be pullable axles as on motorcycles and enclosed drops. Lawyer lips may also helps, so possibly uber bike makers/users should stop the name calling.

- Discs do weigh more, and the forks they run weigh more. Fully loaded touring bikes probably should be dropping the wimpy forks anyway. The fiddly tapered tubing in a lot of touring bikes is a nice vintage look but just as heavy as straighter stronger forks (the thin ends are swaged and have near the same metal in them). The idea there is a lot of useful compliance happening is scary if anything, on a touring bike, that is the job of the tires.

- Easy to adjust, and stay adjusted if the rim wows, better than the rest in this regard.

- Run with either kind of levers required for drops or bars, though you need the right caliper.

- Discs can be fragile, but the are also light and easy to replace, and they are easily found in bike shops in the first world.

- There are rack mounting problems, but they are only integrative. There is no serious difficulty if the discs are designed in as part of the package from the beginning.

- Wheel strength problems are twofold, one is the tweak put on the spokes when stopping, and the other is the need to dish the wheel on the left side also, wherever there is a brake mounted. It's not good news, but it can be dealt with, by solid building technique, and also by future potential mods like a wider than 100 front hubs.

- Disc systems aren't particularly expensive, but they require an added BO on the frame, and also the Avid brake itself. You can pick them up for under 50 per wheel at times, and that is cheap compared to premium rim brakes, but very expensive compared to the kind of tripe that gets fitted to a stock touring bikes, and might cost 10 bucks a pair of brakes.

- It probably is true that discs are not super familiar among tourist. Though for anyone who follows cycling, disc brakes are one of a handful of big gets the cycling industry worked on for a decade, and every tiny improvement was much written about in the mags. Think of discs; hydraulic brakes of any kind; suspension; better shifting derailleur and clusters; aero wheels, etc... Maybe today, tubeless tires.

- Discs are ugly. They have a lot of nooks that catch dirt. There isn't anything really clean in the way of an install like an Exile sprotor mounted, drive side brake on a Harley. Imagine if they had something like that and the hydro was wired through the frame for a cleaner look.

- Some of these issues go away if you mount only a front disc, or a front disc and second brake system. How likely would you be to pop off the front wheel if it was only 50% of your braking force? How serious a problem would hydraulic reparability be if you could fall back on a second brake?

- The final problem with discs is that calipers can be made to work, and they are rather beautiful to boot, cheap, and accounted for on most frames. If it ain't broke don't fix it. I think that is a fair attitude, as long as one keeps an open mind to the circumstances in which rim brakes are a somewhat limited system.

I think in taking anecdotes about stuff like bikes flipping (gotta be a severe downhill in the woods somewhere). Or Thorn's caution on discs, one should consider the source. If you sell bikes with touring style forks and outfit them with flat bars and MTB discs, stuff may happen. I don't think that package of ideas is going to travel well to every bike.

I can mount and adjust either a set of v-brakes or a set of avid BB-7's in about the same time. Neither is particularly hard and both require some care and knowledge to get the best performance out of them. I've seen poorly adjusted discs and cantis.

Rim life will be better on a disc rim for sure, but what is better and does it matter? For a rainy/winter commuter or a tour through mud or really wet dirt roads I'd lean towards discs as they don't wear out your rims as fast. For just about anything else rim wear has never been a factor. This obviously depends a lot on the rider and situation - I've never been hard on brakes or rims - I can't explain why other people burn through pads/rims so fast???

I've gone through Avid BB-7 pads faster than I have kool stop v-brake pads. Not really a huge deal as both kinds of pads are small and light enough that carrying spares is a non-issue. I've not worn through a rotor yet.

I posted the tandem link as an example of the issues discs face during hard use. There was a German mtb bike magazine article that compared how much heat various braking systems could take before failure. The disc systems failed at around the same heat that rim brakes blew out tubes - unfortunately my link to that article no longer works. The problem with over heating IMO isn't the type of brake, but how it is used. I don't think a normal fully loaded touring bike should have brake overheating issues in the mountains with either rim brakes or disc brakes if used correctly, but I wanted to emphasize you can over heat and essentially destroy your rotor on a disc brake just like you can overheat a rim on a rim brake and blow out a tube.

All my discs are mechanical cable actuated. I don't trust hydraulics for a travel bike and for a bike I use in town I'd just as soon stick with cables as they are easy to work with. You might convince me to use a hydraulic disc for winter commuting. I have an original Avid disc brake - essentially a BB-7 which is 7 years old and going strong. I also have a new set of BB-7s and they both functional identically.


V brakes are a slightly different kettle of fish, and I deliberately didn't lump them in with cantilever brakes. Are you? I still hold that adjusting cantis can be a chore. V-brakes less so.

The point I was making about rim life is a reality for a lot of people. Everyone has different riding styles, so people who work their brakes hard will wear out their rims faster. Likewise those who ride in wet and gritty conditons. Is it better to run the risk of a cracked rim in the middle of nowhere and be immobilised? Or to have a rotor warp (the most likely scenario) and remove it and keep riding on the rear brake?

Can someone explain to me why discs are bad when they are so good? Does anyone who's against discs on a touring bike have any anecdotal advice? I'd like to hear about your negative experience with discs on tour that caused you to switch back to cantilevers.

Thanks much for this thread. It has brought out some interesting points, and it has confirmed me in my preference for ceramic rims :). I'll just continue dealing with the pad replacements, which -- although more frequent than with non-ceramics -- isn't really a major issue, for some of us at least.

- Discs do weigh more, and the forks they run weigh more. Fully loaded touring bikes probably should be dropping the wimpy forks anyway. The fiddly tapered tubing in a lot of touring bikes is a nice vintage look but just as heavy as straighter stronger forks (the thin ends are swaged and have near the same metal in them). The idea there is a lot of useful compliance happening is scary if anything, on a touring bike, that is the job of the tires.

This is the only part of your post I have to disagree with. A well made canti-fork can be made very strong and still provide a noticeably more comfortable ride. Sure tires are important in this equation, but your tires and fork work together. I'm far less worried that my cant brake fork is lighter than a disc fork as I am that it provides a more comfortable ride. There is nothing scary about a well designed touring fork being strong and vertically compliant. This element of bicycle design has a long an well established history of success.

Your comment about finding spares in the first world is very valid. If you are touring Canada/USA or Europe getting spares really isn't an issue for any part of your bike. Even if your Rohloff hub flange cracks you can get overnight parts easily in these parts of the world.

V brakes are a slightly different kettle of fish, and I deliberately didn't lump them in with cantilever brakes. Are you? I still hold that adjusting cantis can be a chore. V-brakes less so.

The point I was making about rim life is a reality for a lot of people. Everyone has different riding styles, so people who work their brakes hard will wear out their rims faster. Likewise those who ride in wet and gritty conditons. Is it better to run the risk of a cracked rim in the middle of nowhere and be immobilised? Or to have a rotor warp (the most likely scenario) and remove it and keep riding on the rear brake?

I use v-brakes and they are cantis so ya that's what I was talking about. They are the most popular rim brake AFAIK - I have them on both my touring bikes.

Your example about rim and disc brake failures is a little ridiculous. You don't wear out a rim without warning. If your rim is wearing you'll know and can sort that out. If your disc rotor warps and you put on the rear - great...what do you do the second time? People have toured the whole wet dirty planet with rim brakes and rims wearing out hasn't been a show stopper. It is more a financial/hassle issue if you ride in wet/dirty areas a lot. If I winter commuted regularly I'd use discs no question. If I was riding the Pan American Highway I'd use 26" wheels and rim brakes because getting spares easily would be more important to me.

You have to select the right component for the specific application.

I use v-brakes and they are cantis so ya that's what I was talking about. They are the most popular rim brake AFAIK - I have them on both my touring bikes.

Your example about rim and disc brake failures is a little ridiculous. You don't wear out a rim without warning. If your rim is wearing you'll know and can sort that out. If your disc rotor warps and you put on the rear - great...what do you do the second time? People have toured the whole wet dirty planet with rim brakes and rims wearing out hasn't been a show stopper. It is more a financial/hassle issue if you ride in wet/dirty areas a lot. If I winter commuted regularly I'd use discs no question. If I was riding the Pan American Highway I'd use 26" wheels and rim brakes because getting spares easily would be more important to me.

You have to select the right component for the specific application.

V brakes are a variant of the canti (in fact, V Brake is a registered trademark of Shimano for direct-pull canti) and are not as popular on touring bikes as you portray... because of the issues related to cable pull without a Travel Agent when using STI shifters or other conventional levers. The centre-pull cantilever brake is what I have been referring to as a differentiation. But if you want to be pedantic, that's fine, too. All in the education process :)

As to the failures of rim and disc brake failures -- I do know people whose rims have cracked and failed from wear. What warning is there? How many people actually inspect the concave surface of their rims to check wear? How many know just how thick their rims actually are? I would suggest it is way down the list of things people would check, on tour or not.

For me its simple.
I do not want fuel injection and computer controls on my FJ40 and I do not want disc brakes on my touring bike.
Now, on my XC hardtail MTB they work fabulous. And I can pick the stones out of them to my hearts content!

V brakes are a variant of the canti (in fact, V Brake is a registered trademark of Shimano for direct-pull canti) and are not as popular on touring bikes as you portray... because of the issues related to cable pull without a Travel Agent when using STI shifters or other conventional levers. The centre-pull cantilever brake is what I have been referring to as a differentiation. But if you want to be pedantic, that's fine, too. All in the education process :)

As to the failures of rim and disc brake failures -- I do know people whose rims have cracked and failed from wear. What warning is there? How many people actually inspect the concave surface of their rims to check wear? How many know just how thick their rims actually are? I would suggest it is way down the list of things people would check, on tour or not.

Sorry I'm not trying to be challenging about the V-brakes being cantis, but that's what I use and that's what the people I've toured with use. I use brake levers that pull enough cable for v-brakes so I don't mess with travel agents. My only STI drop bar bike uses centre pulls. So when I see canti studs I think v-brakes.

If you aren't switched on enough to check your rims for wear than I submit you aren't going to adjust your rim brakes or disc brakes optimally. You won't brake effectively and you won't check the spoke tension on your wheels. You'll run your disc brake pads down to bare metal - hopefully not on a heinous downhill. Ultimately you'll run into quite a few preventable problems. It isn't like your rims will wear out over night or that it is rocket science to know what conditions might be of concern. The fact is lots of people just ride their bikes without a great deal of knowledge how they work beyond turning the pedals makes the bike go, shifting makes it easier or harder to pedal and applying the brakes slows the bike. Nothing wrong with that, but at that level of sophistication all the discussions we've had here are irrelevant. I'd suggest going with whatever that rider likes best and just dealing with the outcome.

If you aren't switched on enough to check your rims for wear than I submit you aren't going to adjust your rim brakes or disc brakes optimally. You won't brake effectively and you won't check the spoke tension on your wheels. You'll run your disc brake pads down to bare metal - hopefully not on a heinous downhill. Ultimately you'll run into quite a few preventable problems. It isn't like your rims will wear out over night or that it is rocket science to know what conditions might be of concern. The fact is lots of people just ride their bikes without a great deal of knowledge how they work beyond turning the pedals makes the bike go, shifting makes it easier or harder to pedal and applying the brakes slows the bike. Nothing wrong with that, but at that level of sophistication all the discussions we've had here are irrelevant. I'd suggest going with whatever that rider likes best and just dealing with the outcome.

Agreed!

The trouble is... there are people like that out there touring. No real harm, I suppose. But go through journals on Neil's site, and these issues crop up all the time. Threads like this can highlight issues that might help those people think about and understand their bikes a bit better. Maybe. Hopefully...

ADDITIONAL EDIT: Neil did touch on one thing that is a positive for disc brakes -- the interchangeability of 700 and 26" wheels. I am grateful for another Oz poster, craigdurkee, for making me think about this in a thread he started about this topic. Plus another in Bicycle Mechanics later. Indeed, if you have sufficient width on your fork and chainstays, it is entirely possible to set up thin 700C "touring" wheels, and interchange them with fatter offroad 26" wheel/tyre combination... and if you choose the right set-ups, you don't even have to adjust your computer settings for circumference. I am not sure you can do so that easily with canti/V/caliper brakes.

Now, it's not everyone's cup of tea, but it has some appeal if you have the right sort of frame, and if you want a bike that can comfortably handle the sealed roads, plus do some off-road stuff as well.

Cantilever brakes have been good so far, but disc brakes are starting to look quite appealing. (My bike is set up to accommodate both types, so that's not an issue.)

Last summer, I wore out my brakes on two separate occasions. Each time I was trying to control my speed down a mountain pass and in the rain. The second time, I was nearly in a serious vehicle accident because I couldn't stop quickly enough. If disc brakes provide improved power in the rain and if they don't wear out quickly, I'm interested.

However, cantilever brakes still have a few important advantages. They're simple to adjust and it's easy to get pads or other parts almost anywhere.

"This is the only part of your post I have to disagree with. A well made canti-fork can be made very strong and still provide a noticeably more comfortable ride. Sure tires are important in this equation, but your tires and fork work together. I'm far less worried that my cant brake fork is lighter than a disc fork as I am that it provides a more comfortable ride. There is nothing scary about a well designed touring fork being strong and vertically compliant. This element of bicycle design has a long an well established history of success."

I can agree with that too. We all have ridden comfortable front ends. And there is the old saying about "The fork is the Frame", meaning that is where the art of the feel comes into it. But a lot of the "established history" has takes some hits also. For instance I have ridden bikes with straight forks that have great ride. If there is compliance occurring, meaning deflection that feels good to the rider, a straight line to the axle vs. one with curve would probably be a pretty huge change. It is also pretty hard to believe that there is much deflection occurring between the axle and the crown. I would like to hear a credible explanation of what is happening. I agree something is happening, since they sell various blades. But as mentioned, this recent thread on the now crashed Frameforum set me to thinking about the role of the fork in the new tourer. New meaning lots of front baggage holding down the weight, today's tires, stuff like discs.

With stated admiration for Thorn, I do wonder what is up with the thin old school blades, the fear of discs, the 2" tires. Would the world come to an end if they beefed up the fork?

I am going to have to decide what approach to take with my bike. I ordered some of the last supplies today, so I hope to get started soon. The whole disc duo up from idea makes sense to me, but I also know I can get the cantis working and maybe a sidepull or something for back-up. I'm of two minds which option to believe in right now. I could go even crazier and mount a V rear, a Disc front, and a canti front, that actually works out well for my current levers, 287Vs I wanted to run. I could hook those to the V rear and the MTB disc front, and I could run the bar top brake to the Pedersen Canti. It will be like a Consumer Reports test up front!

There is such a thing as over-kill. If I have to put on a heavier fork to compensate for a heavier brake then I'm not interested. I prefer a touring car to a truck. I'm not hauling the world's commerce, just 30 extra pounds. What's the big deal?

There is such a thing as over-kill. If I have to put on a heavier fork to compensate for a heavier brake then I'm not interested. I prefer a touring car to a truck. I'm not hauling the world's commerce, just 30 extra pounds. What's the big deal?

Well, I was doing a descent down rt 202 in ct on my mtb/winter beater with cantis and a fully loaded bob trailer(+my 300 lb self). As I was nailing the brakes to stop at a stop sign at the bottom of the hill, I could see bits of brake material getting shed from the wheel as I descended the hill. Now, the brakes were able to stop me, but if the hill had been longer or steeper, brake failure would have been a real possibility.

"This is the only part of your post I have to disagree with. A well made canti-fork can be made very strong and still provide a noticeably more comfortable ride. Sure tires are important in this equation, but your tires and fork work together. I'm far less worried that my cant brake fork is lighter than a disc fork as I am that it provides a more comfortable ride. There is nothing scary about a well designed touring fork being strong and vertically compliant. This element of bicycle design has a long an well established history of success."

I can agree with that too. We all have ridden comfortable front ends. And there is the old saying about "The fork is the Frame", meaning that is where the art of the feel comes into it. But a lot of the "established history" has takes some hits also. For instance I have ridden bikes with straight forks that have great ride. If there is compliance occurring, meaning deflection that feels good to the rider, a straight line to the axle vs. one with curve would probably be a pretty huge change. It is also pretty hard to believe that there is much deflection occurring between the axle and the crown. I would like to hear a credible explanation of what is happening. I agree something is happening, since they sell various blades. But as mentioned, this recent thread on the now crashed Frameforum set me to thinking about the role of the fork in the new tourer. New meaning lots of front baggage holding down the weight, today's tires, stuff like discs.

With stated admiration for Thorn, I do wonder what is up with the thin old school blades, the fear of discs, the 2" tires. Would the world come to an end if they beefed up the fork?

I think Thorn gets misrepresented a bit in North America as we only focus in on their expedition touring models which are designed to carry very heavy loads across awful roads/tracks in far flung corners of the planet. Naturally these bikes are overbuilt, use wide tires, very long wheelbases, use strong/comfortable forks. They do have more road touring oriented models and they also have an expedition touring model designed to be used with a suspension fork/disc brakes. The Thorn philosophy, which I agree with, is to use robust and reliable parts that you can source pretty much anywhere. Disc brakes would require a different fork design that wouldn't be as comfortable to use, would not add better performance for many users and would be harder to replace/repair around the globe.

So to answer your question they are using old school fork blades because it is a proven technology that works well. I don't think they are afraid of disc brakes in general they have just decided that rim brakes are a better choice when you look at the whole set of pros/cons. What they are afraid of is someone trying to weld disc tabs onto one of their forks and ending up hurt or killed. I don't blame them for that. If you want to use discs get a fork that was designed to deal with the completely different forces it generates.

I'd also submit that the fork used on their EXP is uber beefy already. We aren't talking about some wimpy roadie fork. The thing is it can be very strong & vertically compliant. You don't have to pick one or the other as long as you are cool with rim brakes.

One thing that you can't argue about the Thorn philosophy or their bikes is that they do have a pretty impressive track record for being taken on some amazingly challenging tours and performing well.

"a fully loaded bob trailer(+my 300 lb self)" Friend—that's a different matter altogether. As would be any sort of "expedition" touring. For regular road type touring and typical physiques — it's all over-kill.

Well, I was doing a descent down rt 202 in ct on my mtb/winter beater with cantis and a fully loaded bob trailer(+my 300 lb self). As I was nailing the brakes to stop at a stop sign at the bottom of the hill, I could see bits of brake material getting shed from the wheel as I descended the hill. Now, the brakes were able to stop me, but if the hill had been longer or steeper, brake failure would have been a real possibility.

You could easily overheat disc brakes with that kind of load. You need to start looking at a drag brake in addition to your normal front and rear brakes with that much weight. I'd head over to the tandem forums and see what they are using.

Even upgrading your front disc to a larger unit may not work as that much braking force could buckle your fork/frame.

It's interesting that most of you think that disc brake-capable forks are less comfortable than canti forks. Is this based on experience? I ride a cyclocross bike with a carbon fork which has disc tabs. I currently use canti brakes. The fork is very compliant and my bike is very comfortable even when I run 100+ psi in my 700x28 slick tires and I weigh only 180 lbs. I'll say it's as comfortable as any steel non-disc fork on the market.

I've ridden bikes with disc brakes and v-brakes. I'll say that v-brakes are more powerful than cantis and easier to modulate at the threshold of lockup. Disc brakes are just plain awesome with good modulation (Avid BB7) and all-weather one-finger stopping capability. Cantis look pretty, but honestly I think such an outdated piece of equipment is still used because mini-v brakes have yet to catch on in the US and because of "historical inertia".

Shimano is working with Fox, and Marzocchi to make a new standard for their standard quick release forks. It's a 15mm quick release thru axle. I'm hoping once it takes off someone will make a steel rigid fork with rack eyelets.

Another way to minimize the chance of a front wheel coming out of it's dropouts from disc brakes is to use a bolt on skewer system.

I'd have to agree with an early post by Vic. Cantilever brakes are simple, cheap, apply their force to the rim, which doesn't stress spokes. When touring, I regard reliability as paramount. Whatever happens, I'd like to be able to fix it, and I don't like things going wrong when they don't need to. I've fixed problems with cantilever brakes using pads from a place which just happened to have a few bike bits, cable with 100lb, fishing leader material. With disk brakes, it's too easy to have some part of an assembly fail that just needs THAT part, until then, no brakes. unacceptable on tour.

I'm very relieved my disc brakes on both my mtb and tourer have very fortunately held up so far after thousands of miles...... Also fortunate in that I've never had to fix the any of my disc brakes with fishing gear either.

The way I see the argument of discs=more complexity, less reliability, it's then a completely logical step to throw away that new fangled derailleur thingy with all those exposed pulleys and joints, or the added complexity of more than 5 speeds at the rear!


I'd have to agree with an early post by Vic. Cantilever brakes are simple, cheap, apply their force to the rim, which doesn't stress spokes. When touring, I regard reliability as paramount. Whatever happens, I'd like to be able to fix it, and I don't like things going wrong when they don't need to. I've fixed problems with cantilever brakes using pads from a place which just happened to have a few bike bits, cable with 100lb, fishing leader material. With disk brakes, it's too easy to have some part of an assembly fail that just needs THAT part, until then, no brakes. unacceptable on tour.

All these posts are fine and dandy -but who here has actually toured on disc brakes? It would make an interesting poll and would be interesting to relate touring disc brake experience versus a positive/negative view of discs. Anyway, for full disclosure, my tourer has discs.

The wonder of the internet boards is that anybody can post anything -I'm not trying to be a disc evangelist (use whatever you like and what works for you) -but honestly there's theory and then there's real life. And if I'd read these posts before I got discs for my touring bike, I should have realized that:

1. the wheels will give way because of the added stress on the spokes
2. my wheels are weaker because they less dish
3. the brakes are too complex and prone to failure
4. I won't be able to fit racks properly
5. the ride provided by a fork with disc tabs is uncomfortable
6. my disc brakes will get knocked about and the discs out of whack spoiling the braking
7. my front wheel is going to separate from my forks
8. I'm carrying extra weight with the discs (actually, I believe this is true, but in all practicality when I'm loaded up, can't say that extra pound makes that much difference)

Suffice to say, I'm still alive. The bike's still in one piece with a working front wheel, I carry panniers on a rack with no problems, I cycle comfortably, the wheels are still together (built them myself) and the brakes (gasp) still work reliably (caveat here: I do not do touring on rough roads nor go to outer Mongolia or similar, though I submit most touring people don't either).

Of course, disc brakes have their own set of advantages and disadvantages -of which I believe the main disadvantages with discs are the expense and possible rack installation issues. Interestingly, if I got a new touring bike today, I probably would not opt for disc brakes based on cost and rack installation issues alone; though I do believe disc brake overall performance is superior, it's not enough for me to warrant the extra money given I could use good quality cantis with Koolstop salmons. However, since I already have discs on my tourer and they are all paid up, there is no way I'd swap them out for another braking system type currently available.

Disc brakes seem to elicit strong responses -I wonder if it is because they are relatively new technology? Or perhaps that people's existing frames tend to not have disc tabs so people with these frames want to dismiss them?

All these posts are fine and dandy -but who here has actually toured on disc brakes? It would make an interesting poll and would be interesting to relate touring disc brake experience versus a positive/negative view of discs. Anyway, for full disclosure, my tourer has discs.

I have toured with disc brakes. I didn't have any major issues and I had a suspension fork up front so comfort was not a problem. Nobody said you can't tour with disc brakes or that you bike will blow up on the first downhill or that your teeth will rattle out...:eek: The point of the discussion in this thread isn't that disc brakes are bad - just that there are pros and cons to both discs and rim brakes. If you want disc brakes and they work for you awesome! I'm not a proponent of any one kind of braking system for all applications. I'm a proponent of making the decision based on a realistic assessment of the pros/cons for a specific situation.

I'm sure there are people out there touring with centre pull road bike brakes - they could report to this thread that they are fine with them. I still wouldn't choose them for my touring bikes.

None of my touring bikes has strong touring specific wheels on them. I've not had any problems so far, but I wouldn't argue that building strong wheels is a bad idea or that there is no difference between a 32H and a 40H wheel for a touring bike.

I was an early adopter of disc brakes in 2000 with a set of the original Avid mechanicals. I still have them and like them a lot. I'll be moving them to a bike project I'm working on this spring, which, funnily enough I'll probably end up touring on this summer. My experiences with disc brakes and rim brakes has taught me that many people totally under appreciate rim brakes and over hype disc brakes.

I've owned 3 different bikes equipped with Avid BB7 mechanical disk brakes:
-A Spicer ti cyclocross/touring frame;
-A Spicer ti tandem
-A Jamis Dakar team mountain bike (1997, without disk tabs, so I used an A2z adapter on the rear dropout).
So I didn't start out as a disk brake skeptic, but in fact was pretty openly enthusiastic about them.


I no longer own the Spicer cyclocross or the Jamis. I still own the tandem, but recently switched out the disk brake setup for Tektro mini-v brakes.

I'm a competant mechanic, & have built all of my bikes from the frame up. In the end, I was dis-satisfied with the disk brakes on all these bikes. Why?

1. Weight: by switiching to mini-v's and a carbon fork on the tandem, I knocked 3-4 lbs off the bike's weight (the tandem had 203mm rotors). That's a lot!
2. Stopping power. Yes, the disk brakes had excellent stopping power, but not subtantially better than dual pivot brakes on a tandem that I just built up for some friends.
3. Setup was easy, but the brakes were finicky and trouble-prone.
-on all 3 bikes the rotor would rub lightly on the caliper once I mounted and rode the bike. The tolerances between the pad & rotor can be quite close, especially with the road version of these brakes. So what looks like a good setup on the mechanic's stand will rub when you put your weight on the bike, remove the wheel for any reason, or steer through a corner. Simply sitting on the bike would add just enough flex to cause light rotor rub. This was very annoying, and accelerated wear on the pads. Backing the pads off to eliminate the rub degraded the braking performance. What's worse, the rubbing noises seemed to come and go randomly, which made diagnosing the problem completely maddening.
-on some occasions, I would get severe cases of rotor rub, suddenly, randomly, without having done anything other than just ride the bike & apply the brakes. Everything was tight, but I would have to stop the ride and do a complete re-centering job on the offending brake.
4. Broken spokes. I even broke a DT Swiss Alpine III spoke, and those things have extra thickness at the elbow for extreme applications.
5. Not touring bike friendly. Most bikes are built with the disk tabs on the left seatstay, which makes for complicated, expensive, or kludgy rack mounting options. There are a couple non-touring bikes which mount the caliper on the left chainstay (Trek Portland, and a recent version of the Specialized Sirrus Pro). But even if you get a rack mounted on there, the Avid mechanical brakes have such a wide profile that the left pannier will likely rest on the brake caliper (possibly not, if you have a chainstay mounted caliper), which will make the brake rub on the rotor simply by pressing in on the left pad dial (as well as adding some flex & pressure from that side).

For these reasons I found disk brakes to be generally dis-satisfying, but particularly unfriendly for tourning use. You might get your Avids to work better on your bike than I did, but then find that they don't work so well with panniersdue to interference, or rubbing caused by frame flex. Their limited extra stopping power didn't justify the extra expense, heft, or hassle.

And thus endeth my optimistic experiment with disk brakes.

Rich

IIRC the reaason you would be breaking spokes is called Torsional Load, when the stress of braking is applied to a disc, and translated through the hub and spokes to the tire. Those stresses lead to the breakage. Check out Buell motorcycles. They use a disc brake that mounts to the lip of the wheel to eliminate torsional load. They lay out all the science on their web site. www.buellusa.com

I'm sorry but I'm having a little trouble with math. You knocked 3-4lbs by removing Avid BB7 mechanical brakes? 4lbs is over 1800 grams -- That's like the weight of a suspension fork.

Price point lists the weight of an Avid BB7 caliper/203 mm rotor combo at 367 grams. I'll give you 400 grams x 2 and you have 800 grams, which is less than a pound.

Avid V-brakes weigh about 240 grams. 240 x 2 = 480 grams.

That's a difference of only 320 grams!

As for the rubbing issues... I can see how a flexy fork will contribute to brakes rubbing in turns, especially with huge 203mm rotors, but that has not been my experience with disc brakes of average diameter.

Everyone mentiones mounting issues with racks, but there are touring bikes with discs and racks, such as Novara Safari and Raleigh Sojourn. I think that issue will be resolved as more manufacturers provide equipment to the increasing number of bikes with discs.

I believe he said brakes and fork.

Everyone mentiones mounting issues with racks, but there are touring bikes with discs and racks, such as Novara Safari and Raleigh Sojourn.

Both of these bikes have rear racks only. IMO, not adequate for touring use.
Is there a front rack that will work with disc brakes?