giskard

I've shortlisted a couple of adventure bikes as my commuter/week-end fun bike: the more expensive bike features fully-hydraulic Shimano BR-RS785 disc brakes, the other bike features TRP HyRd mechanical interface hydraulic disc brakes which perform better than pure mechanical disc brakes and seem to offer the best of both worlds. I must admit I prefer the TRPs as it's much easier to repair or replace a brake cable than it is to repair or replace a hydraulic fluid pipe when you're out in the sticks and miles away from a bike shop that can repair hydraulic brakes.

From reading "hydraulic vs mechanical" forum posts on the web, I understand that pure-hydraulic systems require less force on the levers and require less maintenance as they're closed systems whereas cables stretch and get dirty/jammed up, but I do have questions about the reliability of pure hydraulic brakes, for instance, do hydraulic cables break or split easily? Do they require regular replacement and how long do they last?

I'm at the point where my choice of bike is down to the braking systems, so any advice to help me decide which way to go will be most appreciated.

elcruxio

Adventure bike? I wouldn't put hydraulics on a adventure bike... Getting a hose busted in the wild is a sure way to end a tour ahead of time as hydraulic hoses and bleed kits are much more difficult to source locally than cable/housing sets which you can find in every lbs or even larger super market.
Of course it really depends on how you plan on using the bike. If you don't actually tour, I'd recommend fully hydraulic. The feel in current generation shimano brakes is crazy good.

giskard

I guess I could always carry spare hoses, mineral oil and a bleed kit but they're expensive and will take up luggage space - I'd be using the bike more for commuting than touring, which I do a couple of weekends per year.

dsbrantjr

Contrast the size/weight/expense/availability of all of that stuff with carrying a spare brake cable. May or may not be too bad for commuting and weekend touring, but an "adventure" bike, not so great.

Zef

I have experience with both hydraulic and mechanical disk brakes. One thing that mechanical brakes have going for them is they are less of a pain to get the pads to stop rubbing on the disk. There is no micro-adjustment of the pistons that press against the pads of hydraulic brakes. This becomes an issue almost every time a wheel is removed and reinserted...and typically requires the caliper mounting bolts to be loosened and retightened to get the caliper realigned so the pads don't rub. With the mechanical disk brakes I have seen/worked on the calipers have an adjustment mechanism for the pads which was very easy to use.

With all that I have stated above I should also state that 3 of the 4 mountain bikes in my household have hydraulic brakes (one shimano, two avid). The feel at the lever when set up and bled properly is outstanding and they are very powerful brakes. One thing to choose wisely when looking at a hydraulic system is what type of fluid is available. While mineral oil systems use a non-corrosive fluid it is a bit harder to source and using the company specific mineral oil can be expensive. DOT 5.1 or 4.1 fluid seems much more available around the world and I have lived in the US, Africa, and Europe.

In all my years of riding I have never had a mechanical brake housing (cantilever, road caliper, v-brake, etc) fail except that it became corroded or otherwise gummed up. I have worked on other peoples bike that have kinked the housing to the point it mucked up the brake operation...but have never seen the housing catastrophically fail. Likewise, although a much smaller sample size/period, I have yet to have a failure of a hydraulic brake hose...this includes 5 years of commuting and trail use of a hydraulic brake mountain bike. The 2 most likely scenarios for failure of a hydraulic hose would be getting kinked in storage/transport of the bike or getting ripped out if snagged on an obstacle like a tree branch when riding off road.

If I was choosing a bike strictly based on the brakes I would choose mechanical brakes as they are less fiddly and easier to work on in my opinion. But since choice of bike is usually based on a slew of other factors such as the broader component package and price...the better bikes tend to come with hydraulic brakes so type of disk brake does not enter the equation too much (and thus I have ended up with 3 bikes with hydraulic brakes)...on the other hand if one buys a bike with hydraulic brakes and finds they don't care for them, they can be easily removed and replaced with mechanical calipers from anywhere between $15 to $80 depending on quality/features.

-j

Looigi

Personally, I think the cable actuated hydro brake is ludicrous. Either go hydro or mechanical. I have hydro on my mtbs and would strongly consider/prefer newer mech discs for other applications.

giskard

Thanks for a very comprehensive reply.

If I was to go for the bike with the hydraulic brakes, I could see how I get on with them and if I don't like them, then I could replace them with the cable-actuated TRP HyRds I mentioned in my OP, then sell the hydro brake kit on eBay to fund the expense of changing them.

giskard

Why? Again, why?

rydabent

My opinion of course is that hydraulic actuation is needless complication. Any new cable system may have some stretch and wear in, but one adjustment should keep it in tune for a long time. I have not had to adjust the cable on the disc brakes on my Terratrike Crusier in more than 2 years, and they work great. I put about 1500 miles a year on this trike.

Rootman

As others have stated if you're going to be tooling around in the brambles in tight spaces a hose would come undone when snagged on something quite a bit easier than a cable.

Having said that I have hydros on my Roam 2 hybrid and love them. They take quite a bit less force, my arthritic hands really appreciate it.

As far as adjustments go, twice I've had to loosen the caliper, smash the brake handle and then tighten them. A few times I've had to "slam" on the brakes to rub off crud that was rubbing. I would get them again in a heart beat. Necessary? NO, but I sure do like them and I can think of a LOT of other stuff I've bought (or though of buying) that give a lot less pleasure for the money.

HillRider

I have no personal experience with hydraulic bicycle brakes but I can understand Looigi's point. A cable operated hydraulic brake has the complexity and disadvantages of both systems. If you are worried about cables corroding or jamming, it has cables to do just that. If you are worried about leaks or hose failures, they can potentially suffer both of those too.

The only benefit I see is that they let you use your existing mechanical brifters or brake levers instead of having to replace them with costly all-hydraulic ones. Since the new bikes you are considering won't have legacy brifters or brake levers, either go with an all-mechanical or all hydraulic brake system.

fietsbob

Avid's BB7 has all the individual pieces stocked in the distributor, QBP's Catalog , so it would to my mind be most repairable in the Long run ...
( though super agressive braking has made plastic adjustment knobs too hot.)


Bicycle hydraulic disc brakes are not truly a closed system, because there is an expansion chamber in the lever-master cylinder to compensate for fluid expansion
due to disc friction heat transfer to the slave cylinders in the wheel caliper.

AFAIK only Magura's Hydraulic Rim Brakes are actually a closed system. I own a trekking bike with those.. [+ BB7, I have a set of each on 2 bikes]

The German Magura brake has decades of user time.. they fit in V brake situations ..

their MTB disc brakes seem to be continually changing. upgraded re engineered to be better. ( showing 'new and improved' for the industry trade shows..
and cycling gear reviewing web-Zines..

Zef

To me the pros of the TRP Hy/Rd system are that you get the functionality of a hydraulic caliper and can use pre-existing levers. The cons are that you have the fickleness of centering the caliper on the disk that regular hydraulic systems have plus the added need to set up the cable. Many hydraulic systems come pre-filled and pre-bled so unless there is a need to change the length of the hydraulic hose you basically bolt and go as far as setup is concerned.

Given that there are good mechanical as well as good hydraulic disc brakes currently available at different price points, I can't see why someone would go with a hybrid system other than the fact they are buying a bike that comes with them and the decision to buy such bike was based on other factors other than the brakes.

Hybrid systems like this seem like they are more a "gap filler" until the market offerings for road oriented disk brakes becomes more developed/robust.

-j

well biked

In my mind, it really is a question of how you're going to be using this bike. If you're truly going on tour/long trips, unsupported, then I would favor mechanical discs or rim brakes. I don't like mechanical discs, they are inferior in every way to hydraulics in my experience, except one. The one thing they would do better is to be easier to work on in a DIY on-tour situation. The odds of Shimano hydraulic brakes having a major malfunction are very, very slim, but the possibility does exist, and I wouldn't want to mess with hydraulics out on a long trip, unsupported.

But for the rest of the time, like while you're riding the bike, the Shimano hydraulics are night and day better. I've used all of them extensively, and that's my opinion. It was mentioned earlier in the thread that hydraulics require more work to keep the pads from rubbing, as when a wheel is removed and then re-installed. In my experience, nothing could be further from the truth. Shimano hydraulics are the most trouble free disc brakes out there, and mechanical discs are the most troublesome in regard to adjustment, fiddliness.

I have a couple of customers who use the TRP hybrid brakes you're talking about. They're not bad, but they're not great either. And you still have a hydraulic system to deal with, albeit a smaller one.

I race mountain bikes, have done long distance endurance races that push equipment beyond the normal expectations sometimes, and never have had a problem with hydraulic brake failure or problems during one of these events. Just some perspective to show the unlikelihood of a problem. The often repeated concerns of hydraulic hoses tearing loose, breaking open, etc etc, these possibilities do exist of course, but in the real world, even in extreme conditions, it is highly, highly unlikely. And the trade off for that risk is that you get to use the best brakes out there IMO.

The idea of a true long distance touring/adventure bike with disc brakes is the one situation that I would reluctantly give the nod to mechanicals. FWIW, my touring bike has cantilever rim brakes, and my current commuter has TRP Hylex full hydraulic discs. My mountain bike is equipped with Shimano hydraulics.

FastJake

For commuting use whatever you prefer. Any system can be made to work just fine. But if you're doing real touring on this bike I'd recommend rim brakes or mechanical discs if you can't get rim brakes on the bike you want. To me the "benefits" of disc brakes, especially hydro discs, do not outweigh the possibility (however slim) that they might get broken somehow and leave you stranded.

But to be fair I'm an adamant rim brake fan and don't want disc brakes on any of my bikes, including my year round and winter specific commuters.

fietsbob

AAAnd, there are several companies making a cable to hydraulic converter with the Master cylinders paired and mounted under the stem
Hoses to the Caliper at the wheel ..
Done so as to use the Brifters on your Road bars... where a brake master would go, is full of the shifter Mechanism.


the Trek 720 is coming with the HyRd caliper As stock .So in LBS, I got to fiddle with it In Person.. nice feel.

Interesting feature: a Knob to turn and lock the caliper open.
so the lever wont close the caliper when the wheel with it's disc is Removed.

so also fixes it open to pull the cable tight.

mconlonx

Realistically speaking, if you are considering a bike for "commuter/weekend fun bike," brake issue is moot. Go with all hydraulic. They will not let you down. Get them serviced every year or every other year. Mechanical/hydraulic hybrid is only a temp solution to a problem which is going away.

Cable road brakes are atrocious compared to off-road hydraulic brakes--no manufacturer seems to have nailed the rubbing thing with mechanical road brakes (maybe Tektro Spyre, but I have not tried them).

If you want reliability and repairability beyond disc brakes, like if you are some luddite tourer, you'd be better off with canti or V-brakes.

cale

I think you really have to go with hydraulic, though the levers you reference haven't seen much use (they're essentially brand new) and I have no idea about your talents as a wrench (assuming you're building the bike) or your intended use beyond the vague description provided.

Any concerns about hydraulic line damage are, IMHO, unfounded. It is possible to damage a line but I don't think that it is necessary to anticipate an on-trail repair. The redundancy of front and rear braking makes it possible to return from a adventure in "limp" mode, eg one brake only. The possibility of damage to both lines exists, but suggests a collision or crash of such great magnitude as to essentially put the rider in "limp" mode and, with all the best luck, walking out.

There are a couple of issues that any adventure rider has to contemplate. One is the advisability of going on adventures alone and where there is the distinct possibility of getting stranded by equipment failure of any sort. The second is the measure of risk. The risk to the equipment is tiny compared of the risk to the rider in terms of long-term impact. Biking is inherently dangerous, we shouldn't forget this or we might be tempted to contemplate everything in terms of equipment.

I, too, have been tempted to take a closer look at the Hy-Rd brakes but I think my next move, away from BB7s, will be to a pure hydraulic system. The benefit of a hydraulic coupling, from brake lever to caliper, can not be understated from the standpoint of brake feel and therefore for modulation. The Hy-Rd system will always be susceptible to cable/housing contamination which degrades performance and cable stretch.

Just my $.02

grampa.sjb

Hydros are very powerful, have great feel, but are a real pain to service. I had them on my mountain bike for awhile, but being more a XC rider than dedicated downhiller, the servicing aspect eventually took me back to Avid BB7s, where I have happily remained ever since - I even got them on my new touring bike. The mechs have more than enough power for my needs, and are easier to service than even cantis or v-brakes, let alone hydraulics.

cale

I read "pain to service" and I think "mechanic" not "brake". Have you ever serviced the brakes on your car?

grampa.sjb

I don't know if it was the LBS who installed them, and then, when they kept needing to be bled, couldn't solve the problem (and neither could I - eventually replacing all the tubing, etc, but no joy), so I just gave up on them. They were about the only bike component I've had a serious problem with. So yeah, it could be the mechanic (either me or the ones at the LBS). No, I do not service the brakes on my car. The BB7s on the other hand are dead simple to maintain and never need bleeding.

FWIW, I was talking with another cyclist a few days ago, and he asked me if I knew of any shops that would bleed his hydraulic brakes - he'd been to three and all had refused. Should I send him to you in Seattle?

cale

.
No. Please don't

grampa.sjb

Okay!

well biked

Were they Avid hydraulics? If so, I wouldn't condemn all hydraulics based on your experience. Most Avid hydraulics are generally pretty terrible, often in perpetual need of bleeding. They then rub, have a bad feel at the lever, etc., you bleed them and maybe get temporary good service from them, only to have the problems come back soon. SRAM has addressed these issues over and over again, and I think they may have completely dropped the Avid hydraulic lineup now and market them as SRAM now.

MileHighMark

If you ride in wet/sloppy conditions, the self-advancing pads on hydraulic systems can be a real plus. Also, I've found that DOT-based systems tend to perform better in sub-freezing temperatures.