waterbugg

I'm dreaming up a touring bike to buy and am debating between disc and V brakes. I'm planning on shipping this bike around quite a bit, and someone told me disc brakes don't hold up well to shipping. I've never had a bike with disc brakes, but it seems like a valid concern. Any experiences with that or opinions on one vs the other?

vik 

Disc rotors are easily bent in transit. So it would be wise to pull them from the bike and tape them to a stiff bit of material and put them somewhere protected. If you do that there shouldn't be a problem.

I'm not a huge fan of disc brakes on touring bikes. I have both v-brake touring rigs and disc brake rigs. They both work. The disc brake lovers will overstate the benefits and the v-brake lovers will overstate the problems.

I ride both so I can continue to get experience and evaluate the options. I prefer v-brakes in general, but if you gave me a pimped out disc brake touring rig for free I would ride it happily. I'm at the point where I really don't think too much about what brakes my bike uses since they all work fine - wet and dry, uphill and downhill.

Personally I would see what touring bikes you like not worrying too much about the brakes. Look at the top 1 or 3 choices. Test ride if possible and then start getting down to the nitty gritty like what your brake options are and what racks/fenders to use.

waterbugg

I do have a top 4 list (CoMotion Americano + Pangea, Gunnar Rock Tour + Grand Tour) - some of these have the option of disc or V brakes, some are one or the other. You're probably right, at this point brakes shouldn't factor into my decision ... there are other differences I should think about. Still, good to know a bike with disc brakes can be shipped without too much concern. Thanks.

fietsbob

Rim brakes wear the rim, and the wheel goes down to the water and re wets rim.
Various options:
and Center-lock hubs and discs, would come off more easily.. for shipping ..

Fwiw, Galfer, a California company, discs are significantly thicker than Avid,
.. but Avid's and others, cost less.

mechanical, cable discs are flexed sideways
into the inside pad by the outside one, you should know..




Rim brakes?
I have found Magura HS 33 a superior rim brake , just no drop bar hydraulic lever is made.

The slave cylinders bolt on V brake bosses , but don't use them for pivots.
closed system , snap on /off pads, &
they have Kool Stop make their Salmon /red compound for them.

aroundoz

I always used V's or Cantis but now have a Fargo and I am loving the disc brakes on it but I would be reluctant to take it to a 3rd world country so where you plan on going with the bike could help you decide. FWIW, it's fairly easy to true a wheel on the road but it's almost impossible to true a bent rotor and hearing a disc rub a rotor all day can drive you mad. I met a rider last year who has having this problem and he had been to 3 shops but no one was able to correct the problem.

bradtx

waterbugg, I'm sure there's an easy way to protect the rotors with your packaging system with careful engineering. V-brakes work very well, but I can see where a disk brake would be superior controlling speed on a long, fast downhill run.

Brad

Bacciagalupe

Type of brakes aren't very high on my list of things to worry about. Then again, I'm less and less inclined to tour in areas where a mechanical problem with discs might actually present an issue.

That said, I'd avoid hydraulic disc brakes. It's too easy for the line to get damaged in transit and for you to run out of fluid in the middle of nowhere.

vik 

I don't disagree with your sentiments and there are no drop bar compatible hydro disc levers at this point, but hydraulic discs are the ones that work the best as they don't suffer from housing compression losses like mech discs do. The difficulty field repairing them is an issue though.

fietsbob

with a Cable Disc, seems easy enough to throw a spare caliper in the corner of your pannier.

Mr Pink57

The rotors are pretty easy to fix. Just need a piece of glass (flat surface) some sort of clamp and a few rags to put on the clamp. Lay the rotor on the glass to find the bend then once the clamp has CLEAN rags on it slightly bend it back. Rinse and repeat. You could probably cut out the glass and you a decent table to check. I've even seen people use a soft mallet to softly ding them back.

Obviously the big issue is getting racks/fenders on a bike with discs. However companies like Salsa have done this right I think and the front fender/ rack can be fixed with a long bolt and washers.

I have V Brakes on a older bike with Kool Stop Salmon pads and I must say they are impressive, we've had some real nasty winter up here in MN this past year and the pads always brought me to a stop, I am sure my disc brake bike would stop me just as easily to.

vik 

That's a poor solution. You want the mounting bolts to see a shearing force, where they are strong, rather than a bending moment by cantilevering the rack outboard of the fork and putting washers/spacers to fill the gap. In any hard use that will result in a bent mounting bolt which will eventually fail.

OMM's approach puts the mounting hardware in shear and will work with any disc brake bike [see front rack image below - that rack is going on 7yrs on my LHT]. Some bikes like the Surly Pugsley allow for a hard mount to the frame using alternate braze ons to get around disc rotors [shown above] this works well.

Ultimately you can put racks on a disc brake bike - just be critical of the design as many folks are simply selling slightly tweaked conventional racks with the spacers noted above that are not robust enough for serious use.



BTW - fenders mounted with a spacer on the disc caliper side are fine since the mounting hardware doesn't see significant loads.

vik 

The images here are from my buddy's Pugsley to save $$ he bought a $30 "disc specific" rear rack. By disc specific the manufacturer meant "we added a spacer on the disc side". It performed poorly bending after just a few trips on rough roads. Eventually my Pugsley's OMM racks saw 4 panniers with all our heavy supplies [ice, beer, etc..] that trip and when he got home my buddy bought two OMM racks which served him well fully loaded on the challenging CDN GDR route and many rides since.

waterbugg

Thanks for all your comments. It seems like V brakes might be the way for me to go. I am looking for this bike to tour all over (3rd world countries included), which is why I'm opting for 26" tires, bar end shifters, etc. V brakes seem to fall into the 'more fixable' catagory as well.

cyccommute 

Nicely covered.

There's more to braking than just latching on to the brakes at the top of a hill. If you brake that way with either discs or rim, you really aren't getting the most out of your brakes and you could cause damage to either system...although the discs might take longer to show the problems. There's also the fact that to ride that way is incredibly slow.

I live in a state where there are a lot of very long ups and very long downs. Rabbit Ears Pass (west side) for example is a 7 mile long 5% grade. If you squeeze the brakes all the way down the hill both discs and rims are going to be a glowing puddle of metal and rubber by the time you reach the bottom, not to mention, that you hands are going to look like claws at the bottom of the hill. You have to learn how to pulse the brakes (either variety) to scrub speed and not just keep them on the whole way down. You can also get more out of any brake by learning how to shift weight to increase the effectiveness of the brake.

vik 

+1 - I tend not to brake on long steep downhills - unless we are talking tight hairpin switchbacks. I let the bike run, take the lane if the shoulder isn't appropriate for high speed riding and sit up if I want to slow the bike down a bit.

If you want to keep your speed in check brake hard with one brake and then let go completely. Switch to the other brake and repeat as needed. This will let your brakes cool down between applications.

https://thelazyrandonneur.blogspot.co...e-braking.html

As Cyccommute notes either system can be overheated to failure by poor braking technique.

vik 

There are thousands of Bike Friday touring bikes [20" wheels and rim brakes] like my NWT above out and about riding up and down mountains. Folks are not wearing through rims incredibly fast nor are they blowing tires off rims regularly due to overheating from the brakes. If 20" wheels and rim brakes work fine for touring than larger rims are going to be just fine.

bradtx

"There's more to braking than just latching on to the brakes at the top of a hill. If you brake that way with either discs or rim, you really aren't getting the most out of your brakes and you could cause damage to either system...although the discs might take longer to show the problems. There's also the fact that to ride that way is incredibly slow." --cyccommute

Just was thinking about a worst case scenario of a loaded tourer with trailer decending, not attempting to promote improper braking.

Brad

cyccommute 

A slightly different braking technique is required with a trailer but it's still not a real good idea with any brake to apply it for miles and miles. If nothing else a 7 mile trip at 10 mph would mean using your hands to squeeze the brakes for around 45 minutes. If you could still feel your hands at the bottom of the hill, they'd probably be cramping

I have ridden down Rabbit Ears pulling a trailer. I still flew down it, braking only when I either gathered too much speed (for someone else's comfort) or had to negotiate a corner...which rather wide and sweeping. My 6 month old daughter survived the trip...and still likes speed 25 years later It's not the worst place I pulled a kid trailer either

fietsbob

Muddying the waters .. Magura Hydro Stop, HS33 is a great Hydraulic Rim Brake.
they bolt onto V bosses ..
I have KoolStop for Magura Brake pads on mine.
[oh, I said that in #4] ~o)

BigBlueToe

I'm currently beginning an experiment with disc brakes. I'm building a 29er for a ride on the GDMBR this summer, and I'm using Avid BB7 mechanical discs. I read these forums daily and hear people championing this or that, and it gets me thinking. But I never fully believe until I try something for myself. I've been contemplating disc brakes for awhile. When I decided to try a 29er, I figured it was a good time to also try discs. I've previously had bikes with centerpull calipers, sidepull calipers, cantilevers, and V-brakes. Of those I like V-brakes the best, although my road bike has calipers and my tourer has cantilevers.

All my setups have worked fine, except when I had cantilevers on my old mountain bike. On long descents my hands would get so sore from pulling on the levers that I'd have to stop and shake some life back into them. The trend towards small, 2-finger levers didn't help. Ever try and buy brake levers that are long enough for 4 fingers? Good luck! V-brakes seem to offer enough mechanical advantage that this problem is mostly gone. I've ridden down some of the same descents that used to make my wrists burn, with no discomfort.

So now I'm going to try discs. There are couple of things I'm worrying about as the build progresses. One is that there seems to be less dish on the spoke (is that right? More or less? What I mean is the spokes have less angle coming out from the rims; they're closer to vertical) in order to make room for the disc, particularly in back. We all know that spokes are most likely to break on the drive side of the rear wheel because of less dish. I worry that I'll be even more prone to breaking spokes with the discs. This is a worry for me. I'm a big guy (200 lbs.) and I tend to carry a big load, and I've had issues with broken spokes before. I'm worried that the rough, bumpy, rutted surfaces on the GDMBR will make broken spokes more likely. Yes, I'll be using much bigger tires, but will this be enough?

The other I just read about in this month's ACA magazine. The guy, in an article on what to look for when buying a tourer, says that because discs are only on one side, they put twisting forces on the wheels that can contribute to wheel problems. Hmmm.

Anyway, after this summer I'll hopefully have some results of this experiment. Maybe I'll rave about discs, maybe I'll think they were a mistake, and maybe I'll say they're good but not that much better than V-brakes.

vik 

Mech discs have an issue with housing compression. The small rotor and compared to a 29er rim size means a disc pad has to squeeze much harder vs a rim brake on the same wheel. The increased force ends up compressing the housing rather than ending up in the pad. So you may want to think about upgrading the cable housing to something designed for higher forces like Nokon.

craigsj

Cable discs have no more problem with housing compression than rim brakes do. This belief is a result of incomplete understanding.

There are two types of cabled discs, road lever compatible ones and long travel lever ones. Road lever discs, by virtue of using the same lever, will have the same cable tension as a road rim brake if the lever effort to stop is the same and anyone who uses discs brakes can tell you that discs do not require more lever effort. Mountain variants, because of their longer cable travel, will need even less tension.

How much lever effort is required depends on brake, pad material and choice of rotor, of course, so there is a setup component. That's true of rim brakes as well. It's conceivable that a disc brake could be set up worse than a rim brake but that's meaningless.

So what of vik's "small rotor" explanation? It's true that the effective rotor is smaller but vik is assuming the coefficient of friction is the same which is unlikely. That's not the killer, though. Squeezing the disc pad harder does not mean more cable compression because the leverage inside the caliper itself is radically different. Rim pads must travel a great deal further than disc pads so a disc brake has a huge mechanical advantage inside the caliper. Remember, if you are using the same lever and squeezing less on it to stop then you are using less cable tension regardless of what "experts" say in the blogs and magazines that earn them money. If your lever effort is too high, get a bigger rotor, not the most expensive cables you can find.

Aquakitty

For a cheap solution this works fine...if you don't want to spend $140 on a front rack. It's strong and has gone through a few tours now.

BigBlueToe

Living is learning. I asked for input awhile ago on what size rotors to buy. The general opinion was that since I'm around 200 lbs. and will be carrying a big load I should get big rotors. I bought the biggest ones Avid offered. Is there a downside to that?

nancy sv

Wait til you get to the Andes and have 50 mile climbs and equally as long descents