I now have two touring bikes, one with Disc Brakes (my Croix De Fer) and one with V-Brakes (actually mini v-brakes, on my Soma Double Cross). Having toured on both for long distances I thought I'd share my experiences and which I prefer. Typically v-brakes, or even cantilevers are seen as the standard touring option. Recently though disc brakes have started to become more common. I used disc brakes to cycle across Europe and Asia on my way to Australia without a hint of a problem. They even survived several flights when the bike was un-boxed without even a scratch. So I thought I'd compare them to my new mini v-brakes.
The below is for mechanical, ie cable, disc brakes. I still wouldn't use hydraulic brakes on a tour. They're too delicate, and tricky to service in the field. They also provide far more stopping power than I typically need on a tourer.
- Conditions - they work whatever the weather, and just as well in the wet. Even when it's mucky they deflect dirt very well while continuing to operate. One thing they can suffer from is burn out. Long descents in dry weather means they get very hot, often overly so.
- Adjustability - they're easy to adjust, and require little adjustment once set.
- Lastability - if used properly, pads will last over 7,000km (from my experiences)
- Wheels - it's easy to remove wheels with the discs hooked up, and you can run a buckled wheel without any problems. And there's no rim wear.
- Appearance - this is a personal point, but I find the bike and cables lines are far more attractive than v-brakes.
- Clearance - no need to worry about tyre clearance (for mudguards) compared with v-brakes.
There are some negatives to disc brakes...
- Weight - they are heavier than v-brakes or canti's, adding around 300-400g.
- Cost - they are far more expensive. A full set of v-brakes may cost around £30 whereas a full set of disc brakes, with rotors are nearer £120 (for Avid BB7's).
- Serviceability - in the field if something goes wrong, they're near impossible to correct and spares would be hard to come by depending on which continent you're in.
- Comfort - I've not yet found a comfortable fork for disc brakes. They're all very strong/rigid and hence quite harsh compared to a nice curved fork with some give in it. *Update, Surly do a disc trucker, curved disc fork which looks promising!
Given I'm using Ergoshifters on both my bikes, I can't use full length (100+mm) v-brakes as the lever doesn't provide enough pull. One option would be Travel Agents, but I've not read positive reviews about them (especially for touring) due to the additional curve and strain they put the brake cable under. *Update, I've used Travel Agents on another bike, and while they work well, they're a bit fiddly to set up, and the cable routing just doesn't look natural.
- Lightweight - my 85mm v-brakes (Tectro RX5's) weigh in at around 300g (pads included).
- Cheap - £30 for a complete front/rear set is a lot cheaper than the £100+ a set of BB7's would cost me.
- Powerful - I find them very powerful, some times more so than my disc brakes. Although in the wet they're back to being fairly rubbish.
I have a few issues with v-brakes...
- Clearance - fitting the mudguards under the v-brakes cable and housing is a real pain. By default, my Soma mudguards cause the mudguards to make a lot of contact with the v-brakes. I had to do a custom fit to get them on, and even then it's not something I'm overly happy with. There's around 1-3mm of clearance between the mudguard and v-brake cable.
- Wheels - removing the wheels isn't possible without releasing the cable (which means I have to set them all over again). There is a fix of filing down the noodle so that you can unhook it. I still find my brake-pads hit the frame and *still* don't provide enough clearance (this is only on the rear). *Update, no need to file any noodles! Ergoshifters have an awesome release mechanism up on the brake lever which releases more of the brake cable allowing the wheel to come off.
- Cable Routing - this is done to the side rather than centrally (compared with canti's). It makes the routing a little messy and it's easier to catch on things (I find).
Of the two, I think I prefer disc brakes, although I won't be changing the set up on my Soma.
- Weight is one issue for me as I like to keep the bike as light as possible. 300-400g may not sound like a lot but when put into context that's the weight of a spare tyre of lightweight pair of shoes I could be carrying instead.
- Serviceability isn't such an issue. Carrying an extra rotor adds 180g (or so) to your luggage. And disc brakes are pretty robust as are the rotors. If they can handle mountain biking and passed all the tests on my tour, then I wouldn't consider them fragile. Even if something did go wrong, I'd probably wait for a new part to be shipped to wherever I was, which is probably what I would do with a broken v-brake anyway.
- Cost isn't something that can be changed, it's just something you have to accept. The additional £60 or so, whether it's worth it, is a personal thing.
- Cable routing isn't a huge issue for me regarding v-brakes, but not being able to remove my wheel easily and tyre clearance are two huge and slightly annoying problems I face with v-brakes. And two of the reasons why I prefer disc brakes.
The only thing I'm not yet sold on is comfort. Despite this I did manage a 9 month tour on my Croix De Fer without issue. It's just now that I have my Soma, I realise just how comfortable a curved fork can be.