PeregrineA1 

Now that Surly is going to offer disc brakes on the LHT, I've seen numerous comments in various threads about them. Many folks offering up negatives....and some positives.

I thought I would put out my overall disc brake experience, all related to mountain biking. Real hardcore mountain biking-not boasting, just qualifying the use.

Addressing some of the specific allegations:

Disc brakes make it hard to change a flat-Nope, much easier. Just flip the QR lever and pull the wheel out. Fix the flat, put it back in and on the road. Not much different than rim brakes. Some have complained about alignment. My bike rack in the back of my truck grabs the front fork so I have to remove the front wheel everytime-never had an issue.

Disc brakes are finicky about adjust-I have run four different brands over the course of the last ten years and it's just set it and forget it. Cable types do take a bit more time to set.

Disc brakes are fragile-Not even close. Hundreds and hundreds of hours of all kinds of trails and no damage from foreign objects-sticks, rocks, trees, bushes, gravel, mud, snow-you name it. It is possible to warp a rotor on a really aggressive downhill run if you have undersized rotors and poor technique.

Weight-Yes, they probably weigh more. The wet weather performance would far outpace that concern, particularly since a touring bike is not exactly svelt....

What have I used? Hayes-hydraulic. Good quality, reasonable price. I would use again. Avid-hydraulic. Good quality, reasonable price. I would use again. Avid-mechanical. Good quality, reasonable price. I would NOT use again-very grabby, not progressive at in spite of trying different adjustment and pads. Hope-hydraulic. Incredible quality, high price. I would use again.

One can see my bias towards hydraulic. I have seen concerns about the durability and service needs of the hydraulic system. Again, I believe that mountain biking is a far more demanding circumstance for the hydraulics than touring and I have seen one failure in all the years of being around hydraulic disc brakes and that is a very large sample group-dozens (hundreds?) of people and thousands of hours and miles. The failure was an "O" ring in the caliper and a real PIA to fix.

Do I wish they were an option when I bought my LHT? Absolutely.

fietsbob

Surly is doing catch up , there have been disc brakes on commuter Road bikes for a while..

Avid [SRAM] short pull road disc calipers made that all easy.

Hayes-hydraulic etc. make sure you wipe off the DOT automotive brake fluid ,
it eats paint.

Magura/Shimano use a mineral oil that is not so Corrosive.

PeregrineA1 

Indeed, Surly is playing catch-up. Just my perception that it is an issue that has come to the fore.

...and yes, don't get DOT brake fluid on your paint or decals. Don't ask me how I know (not bicycles, it was a classic car).

ocho

I have toured on my disc braked Vaya, done road rides with the roadies on my disc braked La Cruz, ridden single track on my Fargo, and 2 mountain bikes with discs. There is nothing wrong with discs at all and on my last tour in the hilly regions of WI those discs provided excellent stopping power on down hill runs, especially in the wet. Set up is easy, easier that adjusting canti's which I have on a few bikes and wheel removal is much easier than canti's or road calipers, as you point out.

You have to spend some time with a disc system before criticizing it. I won't say discs are better than another system, they all work fine, I just don't see any negatives.

FunkyStickman

Same here. I probably couldn't have afforded to build up a disk wheelset with a dynohub, I used old MTB parts for everything, but if money wasn't an issue, I'd have loved to build one with disks, just to irritate the roadies on group rides.

Rob_E

I've never really been concerned about disc breaks on the LHT, but there are times when it's wet or snowy when I think they could be useful. Went through some wet and muddy spots this weekend where I wouldn't have minded them. Then I started thinking: my front hub is disc-compatible, so maybe I can get a new front LHT fork and try them out that way.

Mr Pink57

^^This I think is probably the better way to do it, mullet style. If you use Linears now it will just be a matter of swapping the fork and making sure the cable reaches (would probably replace the cable). I also think people get a little ridiculous on what size rotor there are going to need for a touring bike. You would be surprised on what a 160mm rotor can stop, I see a lot of people wanting to get a 203mm which I think is over doing it maybe a 180mm max and up front only.

I have discs on every bike but my winter beater, go figure right.

MassiveD

"Disc brakes make it hard to change a flat"

My thing with flats and just about everything else mechanical is that the bike should be planed for them. There can be strugggles, but if the bike is developed around likely problems, then no system should slow one down to any extent. Make sure tires are easy to remove, wrenches are light and few, etc...

"Disc brakes are finicky about adjust-I have run four different brands over the course of the last ten years and it's just set it and forget it. Cable types do take a bit more time to set."

Most of the finicky arguments I have seen have posited equal degrees of damage somewhere down the road, and in that kind of set-up cantis are often suggested as the winner. I'm not taking sides, I am just representing the general back and forth on this stuff. Bent rim vs. bent rotor. 5 days to nearest bike shop.

Cables are basically it. While there should be hydros for drops, or touring bikes could be more MTB-like in the controls, and while cross bikes are blazing a trail... For the most part in touring disc=cable. Cost is another factor. MY local bike shop has probably 50 4K MTB type bikes at any time, and zero touring bikes at any price. Go figure.

"Disc brakes are fragile-Not even close. Hundreds and hundreds of hours of all kinds of trails and no damage from foreign objects-sticks, rocks, trees, bushes, gravel, mud, snow-you name it. It is possible to warp a rotor on a really aggressive downhill run if you have undersized rotors and poor technique."

Again, the normal fragility argument is packing for shipping related, not in-use related. So this isn't the right page.

"Weight-Yes, they probably weigh more. The wet weather performance would far outpace that concern, particularly since a touring bike is not exactly svelt...."

I think part of the issue is performance related. Properly set up cantis will stop anything in most touring uses cost 16 bucks, and weigh less, pack well, etc... You look at these threads the average speed is like 10-14 mph. It's like discussing helmet types for running marathons, probably not needed for most. But there are performance users in touring for sure, and brakes are one of the places where they are currently let down.

"Avid-mechanical. Good quality, reasonable price. I would NOT use again-very grabby, not progressive at in spite of trying different adjustment and pads."

Right but that is basically what we are talking about,. Check out 4K touring bikes with discs, and as likely as not they are avid mechanicals, the cheaper ones also.

Here is one for 5200:

https://co-motion.com/index.php/singl...ricano_rohloff

"One can see my bias towards hydraulic. I have seen concerns about the durability"

I could live with that if they made real systems for drops. Durability almost always disappears as a reason not to do something once it is realized that the change is here to stay. Reliability can be engineered, so can simplicity. Of course nobody is going to ask tourists what they want and the people this stuff is designed for are not riding for 3 months straight.