Disc Brakes: Hydraulic or Mechanical?

I remember when I was first hired as a bicycle mechanic in a dark and distant age known as Y2K. It was a moment in cycling history when disc brakes were trying to make a name for themselves and were primarily found on downhill bikes. However, in today’s cycling world you would be hard-pressed to find any production mountain bike over $500 that doesn’t come spec’d with disc brakes. Heck, even road bikes are starting to cave under the peer pressure of disc brakes. This isn’t to say that you can’t find a high quality mountain bike that is built to accommodate rim brakes, but those specific bikes are now on an endangered species list. Many frames and forks built today no longer have the brake bosses to even support rim brake calipers.

So what’s the bid deal about disc brakes? Why do they reign supreme in so many different genres of cycling? To put it simply, advantage. The disc rotor, unlike the rim, sits much higher off the ground which decreases the probability of debris collecting on the braking surface immensely. Speaking of rims, was there ever a time when you had to unhook your rim brake due to a broken spoke or wildly out-of-true rim? This isn’t a concern at all with disc brakes, so long as the rim can pass the fork or chain stays, even if severely out-of-true, your braking capability won’t be compromised. Disc brakes also provide, especially in the case of hydraulic disc brakes, more stopping power from the brake caliper itself. This, in turn, requires less hand power from the rider. Less hand power equals more stamina on long descents. And since I’m on the topic of hydraulic disc brakes, let me get to the main point of this article; hydraulic vs mechanical.

There is no doubt, that when performing properly, hydraulic disc brakes are the more efficient system. You can very lightly modulate the brake levers and get an efficient response out of a hydraulic caliper. On the other hand you have mechanical disc calipers which work off cable tension just like your old v-brakes/cantilevers did. There is even more room for modulation with a cable-actuated system but they do require more stopping power from the rider. Both styles perform great in a wide array of conditions. Wether its muddy, snowing, or dusty, there is no question that disc brakes outperform rim brakes.

This is where mechanical disc brakes elevate far above hydraulic brakes. Have you ever heard of that technique your car mechanic uses called brake bleeding? The same technique is used for your hydraulic disc brakes on your bicycle. And if you’re not savvy enough to understand how to bleed your automotive brakes, then you shouldn’t convince yourself that you’ll be saving money by bleeding your bicycle brakes. A lot of knowledge and skill goes into bleeding hydraulic disc brakes, not to mention tools and supplies. Brake companies do sell specific bleed kits with all the needed materials to bleed your hydraulic system. Depending on where you live(i.e. climate, elevation, and trail conditions), the amount of time between brake bleeds will vary. It’s safe to assume that you should have your brakes bled ever 12-18 months, sometimes sooner. For you DIY guys and gals, calipers that use mineral oil opposed to DOT fluid are generally much easier to bleed. As far as mechanical brakes are concerned, maintenance is far cheaper and easier. Cables are roughly $4-$6 depending on the shop and naturally come with far less issues than hydraulic systems. Regular maintenance on a mechanical brake includes cleaning and lubing the cable and housing. This can be done by even the most amateur DIY mechanic. In regards to brake pads, both systems are actually quite equal. In some cases, companies use the exact same pads for both styles of calipers(e.g. Avid BB7 mechanical pads are the same as Avid Juicy hydraulic pads).

Price and Weight
Prices on either system vary. However, the highest end mechanical calipers are far cheaper than the highest end hydraulic systems. When I say cheaper, I’m talking about half the price. As far as weight is concerned, a high-end hydraulic system will most likely be lighter than a high-end mechanical system. The difference in weight won’t be noticeable to most riders. If you are looking to lighten the weight of your bike you should look to upgrade other components before you change out your brake calipers with the intent of saving weight.

Bottom line
It all comes down to personal preference. I personally pick mechanical disc brakes for my bikes. My favorite setup so far has been the Avid BB7 calipers with Shimano XT brake levers. This combination is more than sufficient in my mind. And, as a mechanic, I enjoy the simplicity of maintaining and replacing cables. Remember, if you spend $1,000+ dollars on a production bicycle you will, in almost every single scenario, leave your shop with hydraulic disc brakes. You should be happy and confident with your hydraulic system. You are, after all, now in possession of the most effective all around brake system. Companies are equipping the vast majority of their MTB models with hydraulic systems. Many companies are even sending out high-end road bikes with hydraulic brakes. Case in point, the 2015  Specialized S-Works Tarmac DI2, a $9,500 bike, comes stock with Hydraulic disc brakes. Models such as this are setting the precedent for disc brakes, just as downhill bikes did in the late 90’s and early 2000’s, that will in all likelihood take over the road cycling genre.

I hope you enjoyed this article 🙂
If you have any comments/questions feel free to contact me.

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