Brakes are something that we all have on our bikes, but the kind of brake you have is something that has dramatically changed in the last decade or so. The controversy between disc and canti brakes was at its cusp about 5 years back, but we've had a flow of emails recently asking about disc brakes due to the continued testing of the Polyvalent (with disc brakes for 2018).
A curious side note to these emails is the the preference of brakes varying by location. We've found that folks in the Pacific Northwest are asking for disc brakes and paradoxically, our Thai market reports that the majority of their customers prefer rim/cantilever brakes on their frames. I thought we might look into the world of brakes and see what the pros and con's are for the two major brake types that we at VO use on our frames - disc brakes and cantilever brakes.
To frame this comparison, I'd like to say that I have used both styles of brakes. I've used BB7s on the Polyvalent prototype and liked them. My standard ride for many years is a touring bike with the Tektro CR710 brakes installed.
One of the first things that people talk about with disc brakes is the stopping power. As disc brakes started with MTB's, it makes sense. You want to stop on a dime before you go over that cliff face. It is probably the most obvious advantage to a disc brake bike, the increase in braking performance vs a cantilever brake. It certainly inspires confidence when you are coming down a steep col/pass/gap and need to scrub off speed when sheep start to cross the road in front of you.
When I installed the CR710's on my bike, they were dead easy to set up. They are similar to the Zeste brakes in that each side has a set screw to adjust the spring tension. Tighten or loosen as needed and then tighten the set screws on the straddle hanger when the pads are even and you are good to go. Now I'm not the greatest mechanic at times (ask my wife, she'll tell you. On second thought, don't ask. It brings up old issues that I don't need to be reminded of), but setting up disc brakes was a bit of a pain in the butt. Maybe this is a case of not doing it enough, but they seemed fiddly in comparison to the cantilever brakes, which were so simple to adjust.
One edge for cantilever brakes is that they are lighter than disc brakes. If you look at the weight of two canti brakes (one wheel's worth) you are looking at about 146 gr. If we compare that to the weight of a BB7 brake set up- rotors (160 mm for reference), caliper and mounting hardware- that weighs 351 gr. So about half the weight, even if you take into account some extra bits like cable stops and straddle hangers.
Another aspect that bears considering with disc brakes is the replacement of the braking surface. When I lived in Vancouver and commuted daily on a bike with cantilevers through out the year, I would wear out a front wheel once a year or so. The constant moisture in the air combined with the grit that the pads pick up and impart on the rim would wear down the rim faster then I have seen anywhere else. The first time I saw a disc brake randonneur set up, I asked my friend how he liked it and he said it was great. You only have to replace the rotor every year, not the whole rim. Wow, mind blown.
Is the style of brake on a bike something that is important to you? Does one or the other make you come to a screeching halt when looking at a new frame? Weigh in below with your comments.