I wanted to write a piece about the merits and drawbacks of cantilever brakes and cable disc brakes on touring bikes. Traditionally touring bikes have had canti brakes but discs are starting to become more popular with bikes such as the Surly Disc Trucker and a large proportion of the 2013 Dawes cycles touring range now having disc brakes. I have also been riding a disc prototype at work, basically to see if we like them or not. However rather than coming up with a definitive answer as to which I think is better for touring bikes I’m still confused, I’ve garnered some more knowledge about bikes and myself but not really anything that will let me jump one side or the other of the fence.
The outcome is that to be honest I’m just plain confused, discs do give a bit more stopping power than a set of canti brakes, however in my experience you can get the same power with a set of mini v-brakes like the Tektro RX5’s. Plus I was finding I was having to use almost as much hand strength with the disc brakes as I have done previously with cantilever brakes on steep hills to bring the bike to a stop. However strangely this isn’t something I’ve found on my own ‘project’ bike which has cable disc brakes where the required hand strength seems less. It’s the fact I have better Shimano disc calipers perhaps, but I have a rumbling gut feeling that actually the brake levers make more of an impact than people realise.
The prototype I was riding and my previous cantilever equipped (geared) bike both had 9 speed Tiagra STI shifters, and suddenly I realised how hard these feel when you pull on them. The Sram Rival shifters on my bike feel really smooth and actuate the brakes with nice modulation and good power. The Tiagra levers with both types of brake feel stiff under the fingers when you pull the brakes on like they’re fighting back and although you can modulate the power a bit to scrub speed off rather than stopping outright they just felt really harsh and you really have to ‘honk’ on them hard to get full braking power.
So I’m undecided, I’d like to ride the same disc calipers with my Rival levers to check that I’m right and it is the levers that are disappointing not the calipers, I’d also like to try other Shimano levers (e.g. 105) with these calipers or cantilevers to see if it’s specific to ‘Shimano’ levers.
Yes there are advantages to disc brakes that I can see, namely no rim wear. It’s a lot easier on a long tour to change brake pads/discs than rebuild a wheel but conversely touring rims tend to have a lot of metal in them and not wear quickly. The rim wear argument holds more weight when applied to lightweight carbon wheels for example used in cyclocross.
Clearance issues also come more in to play off road and in the realm of cyclocross when you are dealing with mud clogging so are less applicable to touring bikes. Then there is the issue of things braking/going wrong when somewhere remote. A cantilever is probably easier to fix or replace in more remote countries than a disc caliper but you have to temper this with the fact that in reality how many people actually ride touring bikes to very remote places.
People just seem to make the assumption that disc brakes stop better, when the reality is that actually this isn’t necessarily true. I need to ride more bikes with differing set ups as I mentioned above but actually cable disc brakes don’t seem to be the holy grail of better braking as perhaps people are suggesting. A set of cantilever brakes which are well set up have provided adequate braking for a lot of people for a long time and I think a lot of people are going to be disappointed with cable discs if they make the switch as they won’t meet expectations and hype.
If anyone wants to comment and can provide better engineering knowledge than me, feel free. I am always aware of my limitations.
Postscript: The thing I learnt about myself this week is that I am an anomaly, I’m 6″4 yet only weigh 11 stone. This means my requirements for bikes and especially frames is very different to most of the population. When designing frames you generally have to work on the principle that as people get taller they are also going to get heavier and therefore require stiffer frames in order for the ride not to be ‘floppy’ especially if you are also designing a bike capable of carrying a touring load as well. I don’t fit this trend, subsequently this week I felt pretty beaten up by the prototype. It was too stiff for me and tired me out when riding it day after day. Strangely my own ‘custom’ bike feels brilliant and seems to fit with my physique (even though Lee never asked how much I weigh) probably more through luck than design.
Again I need to ride more bikes though and more people (who are heavier than me) need to ride the prototype. It would be nice to have access to all manner of fancy testing gizmos so that you could scientifically say this bike is x times more stiff than this bike but the majority of bike companies can’t afford this so they go on rider feedback which naturally is human and can vary depending on the riders size, shape, preconceptions and prejudices. The upshot is that a bike might be brilliant for a large number of people but terrible for a few people, and so if you’re buying a new bike (especially made from an unfamiliar frame material) test riding it really can be very important.