NeilGunton

I have a Safari with an Old Man Mountain front rack (Cold Springs). It works just fine with the disc brakes, and the bike is a very capable tourer. I actually have both a Surly Long Haul Trucker (56cm, 700C) and the 20" Safari, and the Safari is currently giving the LHT a run for its money in terms of "what I prefer to ride". I initially wasn't so impressed, but it's a really nice bike. The disc brakes work; they have all the potential issues that people have brought up, but they do seem to work very well. My only complaint is not being able to put the Greenfield rear kickstand on, because it interferes with the rear disc brake housing.

Old Man Mountain have racks that will fit any bike, including those with disc brakes, and if you give them a call then they can always make something work. It's a two man company, so you always get personal service.

https://www.oldmanmountain.com/

Neil

NoReg

"2. my wheels are weaker because they less dish"

You can't argue that, all one can argue is that they are strong enough regardless. What this really does is just guarantee that the wheels will have to be all that more sensibly built.

"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."

Just in my case I most recently read/reread some stuff on their site that was by the head guy about how he generally prefered his bike for on road touring in normal european situations, as best as I can remember it. It did stand out to me he was using 2" tires, not that there is a thing wrong with that, but it does change the kind of bike one is talking about as much as anything can. I would compare that remark to Beckman's proposition that onroad or off he has always found 1.5" tires more than sufficient. Again, nothing right or wrong about this, but if I know someone is designing everything on a bike around high pressure 1.5" tires, that's a very different bike, even if in many regards they almost look like copies of each other. The gearing choices just emphasise the different approach.

"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."

It goes a little beyond that. They do provide them on quite a few of their bikes. Doubtless it's true that where they don't it starts with their confidence that the V-brakes they prefer are sufficient. Thereafter they aren't required to insert features that would make the use of Discs OK. Then they have to warn against their use. Someone reading the literature though, gets the impression these brakes are a bad choice on touring bikes. Then we end up with these threads.

Nigeyy

Two big thumbs up from me for a really sensible thought out post!

Strangely -given it seems to be generally thought that Avid mtb discs are easier to setup than road ones -I had similar issues of disc rub, but only with the mtb versions. For whatever reason the road ones were so much easier to setup and consistent than my mtb ones.

Nigeyy

Aaah I think it was me that posted that. And I can't disagree with it -but I was thinking more in the line of what you said -decent built disc wheels are strong enough, just not a factor if you have them built properly. I really look at that as more of a theoretical issue than a practical one, as everyone should have decent wheel builds for touring. It's one those of things that always comes up when people discuss disadvantages of discs, but I just don't think it's really that meaningful.

Richbiker

Don't forget, I swapped forks, because I no longer needed a steel fork with disk tabs. So there was a big difference between the steel fork and the carbon fork that replaced it. I put the 2 calipers, the 2 rotors, and the fork on the scale and it all came to over 5 lbs. It was also amazing how much a difference there was between one pair of V-brakes and an Avid rotor + caliper. I did the math on the weight savings before I decided to make the change.

Rich

Niles H.

A friend of mine bought a high-end mountain bike with discs front and rear. Before it left the shop, he had them remove the discs and put on V-brakes. He never looked back, and never regretted it.

(He didn't like the weight and bulk and complexity of the discs, and some of the other problems, and he did just fine, even in the rain.)

vik 

Have a look at the EXP R - which is Thorn's road oriented expedition touring bike. With fenders the bike is designed for 1.5" to 1.75" tires

Have a look at the XTC - which is a lighter touring bike that is more road oriented. It is designed for 1.5" to 1.75" tires with fenders.

Thorn's full on expedition models can be used with 2" tires and fenders.

As a point of comparison the 26" LHT can fit 2.1" tires with fenders.

Ultimately I'd rather have the clearance for a bigger tire and not need it than find I want to run a 2" tire and not be able to.

Here is a warning about disc brakes from the EXXP brochure:

"Can I have disc brakes on my eXp? We could fit disc brakes to the eXXp (as this uses a suspension fork)... this may make sense, even with the brakes currently available, if you want to cycle camp, almost exclusively, on mucky alpine mountainbike trails and you always remove the rotors before traveling by air or by bus.

We will not fit disc brakes to our own steel forks and we expressly forbid the modification of our forks to accept discs and we give clear notice that we will not accept responsibility for anyone else’s (rigid steel) forks... there have been too many accidents... caused by the rotational forces prising the axle out of the dropouts. To make a steel fork safe for a disc, it would need a through axle and it would also need to be so “beefy” that it would no longer be comfortable; in fact it would be so harsh, that permanent nerve injury would be a distinct possibility... hardly what is required and/or demanded from a touring bike! We care about our customers and, even if some are willing to risk a potentially fatal accident, we also care about our continued ability to trade... so this issue will never be negotiable.

Reynolds steel forks are a miracle of engineering; they have been developed to be both strong and comfortable, by a process of trial and error, over many decades (before the current climate of litigation!) Hundreds of millions of tough miles have been covered with them... they work! We think that there is currently little point in having (and carrying spares and tools for) a V brake at the front and a disc at the back, especially when you consider that there are no international standards for replacement pads or lines, rotors can (and do) get bent on tour and they are virtually impossible to true again, fluid can boil, pads can glaze over, lines can become detached and spare parts are hard (or impossible) to find.

To repeat myself, although few people have experienced them, XTR V brakes, acting upon ceramic rims, are wonderful brakes... they are easy to work on, they have great “feel” and they are plenty powerful enough... Fiona and I have reached 75 kph on the “Ripio” in Patagonia (almost random collections of different sized gravel, stones and rocks, masquerading as roads) with full kit, on our eXXp’s and were not at all anxious about our ability to “stop within the distance we could see to be clear”! Please note that, because we were using Fox Vanilla forks, we could have chosen discs... had we so wished! Andy B. (frame designer and test pilot) June 2005"

Although you don't have to agree with all of Andy's perspective [I wouldn't worry about nerve damage if I used a disc fork even though I think a curved rim brake fork would be more comfy] his message is reasonable and is based upon a design he has spent a lot of time perfecting &, loads of challenging testing in remote parts of the world.

Again to compare with Surly's LHT you'll see that Surly went with a curved rim brake fork and lots of tire clearance on their design as well. Clearly Andy's perspective is shared beyond Thorn.

Richbiker

Getting back to MrPolak about comparative weights.
First, about online disk brake weight estimates: take these with a grain of salt. First, it's not clear whether listed weights include the rotor or just the caliper. 2nd, Pricepoint lists the same weight for Avid BB7 brakes in both the 160 and 203 mm rotor configuration. That's just got to be wrong if you've ever compared the two rotors' weights. Plus, their listed weight is more than that listed by Avid's website, which listed the BB7 road version at 329 g. I saw one website listing them at 318 and others listing the BB7 at more than 367 g. So who's weight is right, and what does the weight actually measure?

Avid is, and their weight only counts the caliper, not the rotor. According to Avid, the BB7 road caliper weighs 329 g x 2 = 658 grams, converted to 1.45 lbs for a pair. On my crude scale, the BB7 pair came in at 1.5 lbs (including 203 mm adapters), without rotors.

So I weighed the pair of rotors on my crude bathroom scale, and they came in at 1 lb. I had a hard time finding any listed weight for any 203mm rotor. So I checked weight weenies dot com, which listed the Avid 203mm rotors at .98 lbs, so my scale isn't far off there either.

My tektro brakes, for a complete set (2 pair, with pads) from Universal Cycles (the bx3x model): 292 grams, or 10.3 oz.

Now for the forks: I had a Nashbar steel disk fork on this tandem, which according to them weighs 1332 grams or 2.9 lbs. One of the reasons why I made the switch was Nashbar eventually got around to declaring this fork not rated for tandems. When I originally built my tandem, they didn't say anything, and this fork was way beefier than the non-disk fork on my old Burley. But I don't want to take those kinds of risks with me and my stoker, so the fork and the disks had to go partly for this reason in addition to the problems I described earlier. Right now there is no carbon tandem fork that will handle a 203 mm rotor, so there was no possibility of saving weight (much less money) in this category. And if such an animal did exist, it wouldn't be very light.

I bought a tandem rated carbon fork made by Aprebic of Taiwan, the EVO tandem fork. I had a hard time tracking down the weight on this, so I compared similar items made by winwood and nashbar, and settled on a median weight of 722g, or 1.6 lbs.

So let's add this up:
DISK setup:
2 Calipers = 685g = 1.45 lbs
2 Rotors = 444g = .98 lbs
Fork = 1332 = 2.9 lbs
Total = 5.33 lbs

V-brake setup
2 pair v-brakes=292g = .64 lb
Evo carbon tandem fork = 1.6 lbs
Total = 2.24 lbs

Disk Setup = 5.33 lbs
minus
V-brake arrangement = 2.24 lbs
equals
3.09 lbs

I should probably mention that the carbon fork and v-brake version also cost less money.

So given the hassles I experienced with the disk brakes on 3 different bikes and the somewhat increased cost, the extra 3 lbs wasn't justified by their braking power. I live in a hilly area. 3lbs makes a difference.

Richbiker

I actually found the Avid BB7s simple to install and set up. So why did I have so many rotor rub problems?
I'm still wondering, but here are my theories.

1. The Jamis Dakar dual suspension mtb was not made for disk brakes, so I used an A2Z adapter. There was enough space on the rear dropout to clamp the adapter on. But I've heard from other Jamis Dakar owners who DID have bikes that were disk compatible that they also experienced light rotor rub. So I'm thinking that there might have been a slight amount of play in the pivots or dropout / axle interface that led to rubbing. I couldn't detect any noticable play in the dual suspension pivots, but what I can feel with my hands when the bike is on the repair stand, and what happens when I'm actually riding it may be 2 different things.

2. The Spicer bikes were both made from ti. I'm just wondering if the material and construction was insufficiently rigid to keep the caliper alignment from wandering a little when it had a cyclist's weight on it. I actually looked at the caliper alignment with my stoker sitting on her seat, and the alignment was not the same as when the bike was unweighted. So either beefier construction or a different, stiffer material (aluminum) might have given different performance.

In the end, all 3 bikes may have had the same problem: slight amounts of frame flex or play, which threw off the very close caliper - rotor alignment. Rim brakes don't suffer from this effect, because they can afford to have a much bigger gap between the rim and the pads. But I found that to achieve reasonable braking power with the road version of the Avid's BB7, that the pads had to be darn close to those rotors. In my experience, road levers still didn't pull quite enough cable to give awesome braking power, especially on the tandem, unless the disk pads were set very close to the rotor.

Perhaps some time I'll give disk brakes another try. I like the mechanical disk brake concept. If I do try it, it won't be on a tandem (unless I'm touring is some serious mountains and want to avoid rim heating and tire explosions) or a touring bike. More likely another MTB. But I have 7 bikes now, so I won't hold my breath for a return to disk brakes any time soon.

Rowan

I am wondering if people are anxiously blaming frame and fork stiffness (or lack thereof) around the disc brake mounts for pad rub. I am gathering that much of this discussion relies on cable-pull disc brakes such as the Avid BB7. If this is a similar design to the Hayes MX1 I have just acquired then...

These brakes rely on one pad moving across and engaging the disc which then is further moved across the tiny distance to engage on the fixed pad on the other side. It is my thought that subsequent pad rub is due to a tiny amount of residual rotor distortion laterally as a result of this movement.

Two-pot hydraulic brakes (ie, with a slave cylinder on either side of the rotor) suffer from this rub problem to a lesser degree because, as I understand it, the two pads are moving together to grab the rotor. Any distortion in the disc is enough to cause "pad knockoff" which pushes the pads back a slight amount when the hydraulic pressure is released, so pad rub is minimised.

These are the principles that I have learned from my motor sport days, and "pad knockoff" is one of the reasons why sedan/touring car race drivers dabbed the brakes several times before severe braking, to get the pads back closer to the rotor.

I know nothing hinges on this as far as the topic is concerned, but I thought the observation was needed.

I also question the claim about wheels leveraging out of forks. I think as was also mentioned in an earlier post by another person, this might be a problem of fork dropout design and the observation is coming from someone who is reluctant to change the current design to accommodate disc brakes (ie, the mass production machines are too expensive for that manufacturer to change).

In addition, I have been reading a lot of reviews lately for disc brake-capable hubs, and the stresses, I would suggest, are translated into the bearings more so than the other wheel structures. I've noticed that Shimano Deore and higher hubs with cup and cone bearings have been getting a beating in particular. However, these reviews are being posted by the guys who give their bikes an almighty going over when they ride them -- the 4X, street-ride and downhill mob.

Of course, through-bolt design already is being accepted into the MTB community. I do have to say though that it seems something of a retro step if you are enamoured of QR axles.

EDIT: If you have just read this, reload... I had to make a few minor and one major change.

cyccommute 

Another part of the equation that people forget is braking technique. I've ridden bicycles in all kinds of weather with all kinds of loads and using disc, cantis, v's, drum/canti, dual pivot road, single pivot road, and Weinmann center pulls. With the exception of the center pulls (worst brake I've ever used!), they all worked and stopped me well in all conditions and terrain. Even a tandem equipped with only cantilevers (I took off the drum brake) can be slowed and stopped in mountainous terrain using the proper braking technique.

The mistake most people make is to start at the top of a long hill and ride their brakes all the way to the bottom. I have downhills in my backyard that can go on for literally hours. You don't want to leave the brakes on for the entire downhill or you're going to end up with a pool of molten rubber where your brakes used to be.

Better to let the bike run for a short distance, clamp the brakes down fairly hard and slow quickly then get off them again. The bike may temporarily go faster than you like but the rims and brakes will be cooler and last longer than if you leave them on all the time. As you come to corners, brake harder before the turn, then off the brakes in the turn. I'm not saying that you need to go 50 or 60 mph on a downhill...but if you don't you're missing half the fun of bicycling...but you shouldn't do a 10 mile downhill at 15 mph either.

I've never had a problem with brakes or pads and I don't replace pads that often. I certainly have never had to replace a set of pads at the bottom of a hill...that includes Trail Ridge Road - 40 miles of gravity induced joy!

vik 

I'd had the disc brake rub issue before and I use Avid BB7's. It isn't a big deal, but it can be really annoying.

What is worse is disc brakes that squeal. I've had 3 sets of Avids and only one set squealed badly, but I couldn't resolve it. I tried cleaning the rotors, cleaning and then replacing the pads. Nothing fully fixed the problem. I've got two other sets that are pretty much quiet.

I've had squealing problems with v-brakes as well, but I've got a virtually sure fire system for getting rid of it by proper pad toe-in.

Rowan here is a page about brakes coming out of the drop outs. I don't vouch for the information and I haven't checked all the math. I'm just providing it if anyone is interested in the topic.

I'm curious do you guys that are running discs do you take the time to align the rotor and disc pads so they are parallel?

If you are running single piston discs how often do you adjust the pads so the rotor is in the position spec'd by the manufacturer relative to the inboard and outboard pad?

One tip for anyone touring with Avid BB-7s you can swap the calipers front to back. So if you have a problem with your front caliper you can replace it with the rear to get you down the road.

Nigeyy

I think these are all good points -I had a true floating calipre disc brake (Formula Activa), but due to it's lack of braking performance (well at least compared to the Avids) I had to adjust the pads to be *really* close to the disc. Even then, the brake on the front didn't perform that well, and the rear was still adequate. Because of the closeness of the pads, I still had a lot of disc rub though. My Avid cable discs are now setup nicely, though as I said somewhat strangely the road discs seem to suffer from far less disc rub than my mtb discs.

I also want to pass a comment on the front wheel of a disc brake coming out: I'm sure the wheel can come out as there is leverage to do so, but I wonder if it really is a realistic risk. First and foremost, I have never had my front wheel come out when I've been using disc brakes. Course, that doesn't mean to say it can't happen as it's just my very limited experience, just that I've not heard of anyone having their front wheel come out with disc brakes. Not from my friends nor from any LBS. Since there's probably quite a number of people out there MTBing with discs (and with QRs!), I'd have expected to have heard quite a few tales of woe by now from at least my friends or LBSs. Granted I haven't gone around asking the question, but you'd certainly think it would be something worthy of mentioning! I wonder, even if it does happen, whether it would be more of a function of filing off the lawyer lips, fork design (no lawyer lips or open fork dropouts at a bad angle), either the QR failing, or someone failing to secure a QR properly (and interestingly, if that's the case, whether you have disc brakes or not might not matter anyway then). Anyway, if this preys on anyone's mind, the solution is to go with a through axle.

So if anyone (or knows someone fairly directly who has) has had a wheel come out due to disc brakes... please post with all the details -I'd be interested to know what fork it was and the size of disc used.

MrPolak

Getting back to Richbiker about the weights - thanks for the explanation! Adding the weight of missing 203mm discs makes sense.

HardyWeinberg

My disc bike, the front brake squeals when I brake, and there is nothing I've been able to do about it (I've also tried everything I can think of). In the wet, seems like I can give a few hard brakes and then it will stop, but then another just couple blocks and it's squealing again. It is ... not quite *beyond* annoying, but it makes it hard to unclench my teeth while riding.

Richbiker

Two posters mentioned problems brakes squealing. That's a common problem, but on the mechanics forums they all pretty much say clean the rotor with de-natured alcohol and a clean rag. So I got myself some de-natured alcohol, helped myself to a couple shots and then cleaned the rotors. The squealing stopped. Ok the part about drinking the de-natured alcohol is not true, and don't do it. But cleaning the rotors did stop the squealing noise, at least until the rotors got dirty again.

Rowan

Just a question on this as well... when assembling my rotors on to the hubs, I carefully examined the etching on the second disc. The arrows for rotation point in a direction that is actually, to me, counterintuitive. That is, I would have mounted (and in fact did the front one before I read the "instructions") with the "spokes" trailing backwards, but in fact they are required to point forwards. Is there a possibility that orientation also might have an influence on brake squeal and overall performance, including modulation?

mrveloman

I think a key issue in selecting any equipment for touring is how will you be able to make repairs should a part fail. On a 1 week supported tour on Banff a few years ago there was a couple along with us who had a high end tandem with hydraulic disc brakes. Coming down from Takkakaw Falls a part on their brake system failed. There was no way to get a replacement part and that essentially ended their tour for the rest of the week. On an unsupported tour you would be stuck until you could have a new part shipped to you whereas with a cantilever or V brakes most local bike shops (and in some cases even Walmart) would have parts if you weren't already carrying them.

Newspaperguy

If availability of parts is an issue now, it won't be in just a few years, at least in Canada and the U.S. The brakes are becoming more and more popular. However, in other parts of the world, the technology might not catch on as quickly.

vik 

On my discs with squealing problems I did the following with no success:

- cleaned the rotors with rubbing alcohol
- sanded the pads down
- replacing the pads
- aligned the disc rotor and pads so they were parallel
- adjusted the pads so the rotor was positioned in accordance with manufacturer's specs

The strange thing is I have other disc brakes same model and brand that don't squeal - go figure!

Rowan

Redundancy is a good thing. Many suspension forks have both disc and brake options, as do quite a lot of MTB frames. Provided you are running cable-pull discs, converting to cantis wouldn't be an issue.