Shimano hydrodisc failure

[oldfatslow]

http://www.bikeradar.com/road/news/article/shimano-r785-road-hydraulic-disc-caliper-failure-45088/

I want hydro disc brakes for my tandem but none exist. All the manufacturers specifically exclude tandems as they said they fluid would boil given the weight and potential momentum.

Scary to see this -- I thought the singles were sorted. We did equip our new 29r adventure tandem with TRP Spyres which is a dual mechanical piston design. We are super happy with them, easy adjustment, great modulation, and huge stopping power. Head and shoulders better than BB7's IMO.

[eBAUMANN]

this is a pretty good argument for mechanical discs on long/remote rides. Id much rather deal with adjusting a cable than leaking fluids when 80mi from home, thats for damn sure.

I love the idea of hydro, but when it goes wrong you are screwed.

[guido]

Those Paul Klampers are looking pretty nice right now...

[CMiller]

That looks no fun to discover on a ride. I'm hoping that the shots were cut from different segments because no way I'd bomb a hill with confidence like that with such a severe mechanical failure on the rear brake, not knowing if there was an issue with set-up on the front as well.

Of course, a foot in the tire stopped me on my first bike, why not a Tarmac? :)

If I were building a tandem I'd probably shoot for those Pauls, I bet they are as sturdy as it gets.

[seanile]

paging all sram haters

[christian]

When you're riding along for a minute or two and the brakes feel spongy, it's a good idea to stop and diagnose them.

[fogrider]

so with a rim brakes, if there is an issue, I know I can pull over and depending on the issue, maybe fix, what are my options with hydro bakes?

[eBAUMANN]

so with a rim brakes, if there is an issue, I know I can pull over and depending on the issue, maybe fix, what are my options with hydro bakes?

call a cab

pretty soon, your derailleurs will also be able to leak... (http://www.roadbikereview.com/reviews/rotor-uno-hydraulic-groupset-for-road-set-to-launch)

[MattTuck]

call a cab



who calls cabs anymore? uber, my friend ;)

[chiasticon]

so with a rim brakes, if there is an issue, I know I can pull over and depending on the issue, maybe fix, what are my options with hydro bakes?
with rim or mechanical disc brakes, if you broke a cable or some part of the caliper itself, you're equally screwed. of course it's arguable that they're a simpler mechanism and thus less likely to fail than hydro...

[preludervtec]

I'm pretty disappointed in Shimano's initial response after they discovered the problem. They could have provided more explanation as to why it may have failed. I hope the article gets updated with answers to his additional questions.

[fogrider]

with rim or mechanical disc brakes, if you broke a cable or some part of the caliper itself, you're equally screwed. of course it's arguable that they're a simpler mechanism and thus less likely to fail than hydro...

Yeah, if a cable broke, there is not much that can be done. but a mechanical brake is pretty simple...pads could be out of alignment, easy fix. loose bolt, easy fix. most things on bikes are visible and readily adjustable, and even with a mechanical disc, it sounds like there is little mystery. with hydro disc, we are depending on seals and calipers not cracking not cracking...is that something you can see and inspect for?

[bfd]

That looks no fun to discover on a ride. I'm hoping that the shots were cut from different segments because no way I'd bomb a hill with confidence like that with such a severe mechanical failure on the rear brake, not knowing if there was an issue with set-up on the front as well.

Of course, a foot in the tire stopped me on my first bike, why not a Tarmac? :)

If I were building a tandem I'd probably shoot for those Pauls, I bet they are as sturdy as it gets.

Actually, Santana does NOT recommend front disc brakes for their tandems:

http://santanatandems.com/Techno/BrakePower.html

Now, I don't know if they've tested the new Paul disc brake. Good Luck!

[eBAUMANN]

with rim or mechanical disc brakes, if you broke a cable or some part of the caliper itself, you're equally screwed. of course it's arguable that they're a simpler mechanism and thus less likely to fail than hydro...

not necessarily EQUALLY screwed...a friends RD cable snapped 30mi into d2r2 this weekend, he rigged it up in the rear (https://instagram.com/p/6tCMy9POWu/?taken-by=ddytdy) and was able to ride another 60mi shifting only in the front.

brakes though...you could probably at least rig it up to be hand-actuated (no lever) depending where it breaks.

so yea, handicapped maybe, but not SCREWED.

[christian]

I think that chart/picture is ridiculous. That said, I have Magura hydraulic rim brakes on my tandem, which are obviously the best. (Actually, they are really supergood, but not as good as M785 brakes.)

[CiclistiCliff]

This is why you buy the hydro levers and mate them to XT calipers.

The new road calipers are different and boom, guess what failed!? The new calipers...

[christian]

brakes though...you could probably at least rig it up to be hand-actuated (no lever) depending where it breaks.

so yea, handicapped maybe, but not SCREWED.
I'm sorry Eric, but this is absurd. You have two brakes for redundancy. One is a cable snapping, and one is a leak. I think hydro leaks are less likely frankly.

[binouye]

I want hydro disc brakes for my tandem but none exist. All the manufacturers specifically exclude tandems as they said they fluid would boil given the weight and potential momentum.

Scary to see this -- I thought the singles were sorted. We did equip our new 29r adventure tandem with TRP Spyres which is a dual mechanical piston design. We are super happy with them, easy adjustment, great modulation, and huge stopping power. Head and shoulders better than BB7's IMO.

Thanks for the link.

I've put XT M785 disc brakes on our Co-Motion tandem, ignoring manufacture's advice. I use 203mm R86 IceTech rotors, and a Jagwire hydraulic line for the rear because Shimano doesn't make one long enough to reach the back of the tandem. So far I've been happy with the braking, including going down some long steep hills in Colorado.
BUT (and its big qualifier) our total tandem team weight is only a little over 200 pounds, because the stoker is 6 years old. Total bike weight with me, kid stoker, and 2 rear panniers as we went down steep hills in Colorado was probably 275 pounds. So I don't think we're actually pushing the performance limits of the XT brakes that much, especially with the big rotors, finned pads, and me being careful not to drag the brakes too much.

The XT brakes are much nicer than the BB7s that came with the tandem (I use the XTs on my single MTB also). I've got TRP Hy/Rds on a single now, but haven't tried the Spyre's yet. I'm also curious how the new 2-sided Rever mechanical discs perform. They won't sell me just a caliper though, and I haven't wanted to buy their whole "kit" just to test them.

[Neil]

From reading that article the M785 is known* to crack pistons, anyone know if the XTR caliper has the same issue?

If not, then I might upgrade my callipers to XTR give that they're pretty affordable: http://www.chainreactioncycles.com/shimano-xtr-m9020-trail-disc-brake-caliper/rp-prod119767?gs=1&gclid=CNnb45yTxccCFQ4SGwodZBQFWQ&gclsrc=aw.ds

*For a given value of known.

[charliedid]

Anything can break. Are there other cases reported/known with this same problem?

One dude's bike does not a major problem make.

[oldfatslow]

BUT (and its big qualifier) our total tandem team weight is only a little over 200 pounds, because the stoker is 6 years old. Total bike weight with me, kid stoker, and 2 rear panniers as we went down steep hills in Colorado was probably 275 pounds. So I don't think we're actually pushing the performance limits of the XT brakes that much, especially with the big rotors, finned pads, and me being careful not to drag the brakes too much.


My handle is Oldfatslow. I think I've made poops which weighed more than 200lbs. I tandem with my wife and I would estimate our total weight is 350lbs (I've been married a long time so let's say I weigh 310lbs, the bike 30lbs, and my wife the rest).

We really like the TRP Spyres on our adventure tandem. We have them with 203mm rotors as well. Great modulation. Huge stopping power.

I think they will figure out the hydro brakes. After all, they can stop much heavier motorcycles going much faster, right? They just need to strike the right balance between that proven tech and weight and size for bikes.

[oldfatslow]

I've put XT M785 disc brakes on our Co-Motion tandem, ignoring manufacture's advice. I use 203mm R86 IceTech rotors, and a Jagwire hydraulic line for the rear because Shimano doesn't make one long enough to reach the back of the tandem. So far I've been happy with the braking, including going down some long steep hills in Colorado.


I forgot to ask -- what lever are you using. We are running Ultegra triple 6703 shifters. No Shimano triple hydro was another gap (in addition to it will fail and you will die) which caused us to go mechanical.

[kevinvc]

Will somebody please correct the typo in the thread title?!? My OCD can't take it!

(this is not meant to be an insult to the original poster)

[oldfatslow]

Will somebody please correct the typo in the thread title?!? My OCD can't take it!

(this is not meant to be an insult to the original poster)

As a guy with four consecutive consonants in his name you'd think I know that it's the vowels you need to pay for.

[oldpotatoe]

Will somebody please correct the typo in the thread title?!? My OCD can't take it!

(this is not meant to be an insult to the original poster)

What typo?

[eBAUMANN]

I'm sorry Eric, but this is absurd. You have two brakes for redundancy. One is a cable snapping, and one is a leak. I think hydro leaks are less likely frankly.

haha i only mean in terms of getting yourself home in one piece. even 1.5 brakes is better than 1 and 1 is better than none.

[oldpotatoe]

haha i only mean in terms of getting yourself home in one piece. even 1.5 brakes is better than 1 and 1 is better than none.

When wet discs are all the rage in the 2017 TdF...this won't be the last time you see a disc brake fade to zero...for whatever reason. How many brakes fail at the TdF because of broken cables? Class?

I am sure the axle/dropout/QR/rotor size/caliper placement/alignment will be 'standard'.....you......bet....

[kevinvc]

Oldfatslow - thank you for accommodating my entirely unreasonable request. For some reason I fixated on this and couldn't stop myself from reloading the page every few minutes to see if it was still there. I literally breathed a sigh of relief this last time.

Back to the topic - my Avid Juicy brakes on my mountain bike are fantastic. I was not enamored by my BB7 brakes on a road bike I owned briefly. My Dura Ace 7800 calipers give me all the stopping power that I need on any descent.

[gavingould]

so.... one caliper out of thousands in service?
and the guy was able to safely descend another 5k feet using only the front?
i must be missing where the sky is falling.

every product has a failure rate.
doesn't matter who makes it, what the spec is, nothing is 100% forever.
the sooner you accept that the better off you will be.

[11.4]

I saw the article by Ben D and just saw this thread. The article was basically a waste of time to read. There isn't anything on a bike that hasn't failed at one time or other. No one has reports of other R785's failing, and there are an awful lot of them out on the roads now. To suggest that M785's are failing but provide no info or citation or frequency, and to suggest that that means R785's must be bad too, is simply irresponsible. I'd like to see a coherent response from Shimano, but from the way Ben wrote his articles on Velonews and elsewhere, he must have been bat···· at Shimano and probably not with the people that could have responded with the data commensurate with Ben's ability to disseminate his gripe. A mention is fine; I have no problem with that. Or with an inquiry about other failures. But this article was just to foment a problem, even though Ben went on to say he rode the rest of his 5000 foot descent with one brake. I'm just disappointed.

[pbarry]

I think that chart/picture is ridiculous. That said, I have Magura hydraulic rim brakes on my tandem, which are obviously the best. (Actually, they are really supergood, but not as good as M785 brakes.)

Magura should have a big share of the hydro disc/caliper market right about now due to their very early R&D/development/production. Anyone know the back story on Magura?

[pdmtong]

http://www.bikeradar.com/road/news/article/shimano-r785-road-hydraulic-disc-caliper-failure-45088/

I want hydro disc brakes for my tandem but none exist. All the manufacturers specifically exclude tandems as they said they fluid would boil given the weight and potential momentum.

Scary to see this -- I thought the singles were sorted. We did equip our new 29r adventure tandem with TRP Spyres which is a dual mechanical piston design. We are super happy with them, easy adjustment, great modulation, and huge stopping power. Head and shoulders better than BB7's IMO.

any hydro is better than the POS BB7

Actually, Santana does NOT recommend front disc brakes for their tandems:http://santanatandems.com/Techno/BrakePower.html Now, I don't know if they've tested the new Paul disc brake. Good Luck!

Bill Mc and Santana are THE LAST folks I would take tandem advice from. in the 80's they ruled. Once co-motion came along they prove again and again they do not have a clue.

My handle is Oldfatslow. I think I've made poops which weighed more than 200lbs. I tandem with my wife and I would estimate our total weight is 350lbs (I've been married a long time so let's say I weigh 310lbs, the bike 30lbs, and my wife the rest).

We really like the TRP Spyres on our adventure tandem. We have them with 203mm rotors as well. Great modulation. Huge stopping power.

I think they will figure out the hydro brakes. After all, they can stop much heavier motorcycles going much faster, right? They just need to strike the right balance between that proven tech and weight and size for bikes.

I have HOPE six piston ti on our full suspension ventana. 203/185. team weight 290, bike wieght 40. one finger stopping down grades that would endo a single mtb.

yes, this is a flat bar set up but even if I had a road tandem I'd still run it flat with ergon grips and bar ends. HOPE will ship a tandem length rear hose on request.

[benb]

If there is anything actually wrong with the design of these brakes I'm sure you can blame it on the typical bike industry weight weenie nonsense.

Anyone know if ceramic pistons are common? I've never seen them before.

Regardless he was fine with just the front brake. He'd probably have been fine with just the rear brake.

[peanutgallery]

One point no one has brought up, DOT fluid vs. mineral oil. Pretty sure that there's a big difference with boiling points, acceptable weight and all that

Personally, I've used XT brakes on most of my mtb's for many years with nary an issue until this past winter. I had a rear caliper go bad, leaky piston that kept fouling pads - probably cracked. After 4 years of abuse and never doing anything other than change the pads I was content to by the new ice tech version for like $150 and called it a day.

[zap]

Actually, Santana does NOT recommend front disc brakes for their tandems:

http://santanatandems.com/Techno/BrakePower.html

Now, I don't know if they've tested the new Paul disc brake. Good Luck!

Santana has made very poor equipment choices in the past and their technical expertise............they have none.

[oldfatslow]

I have HOPE six piston ti on our full suspension ventana. 203/185. team weight 290, bike wieght 40. one finger stopping down grades that would endo a single mtb.

yes, this is a flat bar set up but even if I had a road tandem I'd still run it flat with ergon grips and bar ends. HOPE will ship a tandem length rear hose on request.

Any idea why Hope stopped making the 6-piston?

Regardless, I'm waiting on a solution designed for drop bars (brifters).

[oldfatslow]

Shimano & TRP specifically states that you should not use their hydro brakes on tandems. SRAM and Hope Tech did not have those exclusions (I would ping them directly for more info if I was going down either of those paths).

I am willing to take great risk on my single than on my tandem. Most riders, especially those who rides with their spouses/significant others, are the same way. I wonder if the speeds on MTB are presumed to be lower and thus less risk (I think that's a bad assumption if true). It could also be that the flat bar lever allows you to create more pressure to engage a hydro system. Regardless, I'll give them time to figure it all out and make it bullet proof before I head there. My TRP Spyres on my adventure bike and the Paul Mini-Moto's on the Speedster are awesome.

Shimano

http://si.shimano.com/php/download.php?file=pdf/dm/DM-BR0008-00-ENG.pdf

Shimano disc brake systems are not compatible with tandem bicycles.
Because tandem bicycles have a high overall weight, the load on the brake system increases during brake operation. If hydraulic disc brakes are used with tandem bicycles, the oil temperature will become too high and vapor locks or ruptures in the brake hoses may occur, and this will cause the brakes to fail.

TRP

HYRD

http://www.trpbrakes.com/userfiles/file/TRP%20HYRD%20Technical%20Bulletin%20English%20Rev% 20B.pdf

The HYRD brake system is an open hydraulic brake designed for
use on single rider bicycles.

Helix

http://www.trpbrakes.com/userfiles/file/HYLEX%20MANUAL%20REV%20A070213.pdf

WARNING - This braking system was designed for use on a single rider bicycle. Use of this system on any other vehicle or apparatus will void the warranty and possibly causing you great personal harm and injury.


SRAM

I couldn't find anything on SRAM's site on weight limits or exclusions for tandems on the SRAM website.

Hope Tech

I couldn't find exclusions for tandem's on Hope Tech's website.

[Mark McM]

with rim or mechanical disc brakes, if you broke a cable or some part of the caliper itself, you're equally screwed. of course it's arguable that they're a simpler mechanism and thus less likely to fail than hydro...

Some people carry spare brake cables with them (this was more common with MTBs). In any case, a spare cable is very small and light, and a cable can be replaced in just a few minutes with common bike tools (usually only requires an allen wrench or two). So no, you are not necessarily screwed if a brake cable breaks.