[kickstand]

congratulations! you're special! do you want a trophy?

i wasn't talking about just you, but all riders.

I do want a special trophy.

The thing is, I think enough people aren't having the problems that you're bringing up for the industry to develop gear boxes.

You know, kinda evident by the fact that everyone still runs derailuers and no one is developing bikes around gear boxes (on a mass scale from the major manufacturers).

But, that's just like, my observation. Maybe where you live everyone is Single Speed or on Gear boxes because derailuers are illegal or something.

 

[jonKranked]

I do want a special trophy.

The thing is, I think enough people aren't having the problems that you're bringing up for the industry to develop gear boxes.

You know, kinda evident by the fact that everyone still runs derailuers and no one is developing bikes around gear boxes (on a mass scale from the major manufacturers).

But, that's just like, my observation. Maybe where you live everyone is Single Speed or on Gear boxes because derailuers are illegal or something.

you sure are caught up on the details. your anecdotal evidence that you haven't had an incident of occurrence does not change the fundamental risk of such occurrence, which is what i was saying in my post.

the underlying message i was conveying is that for all the changes that have occurred in drivetrains over the last few years, they've all been incremental improvements at best. today's derailleurs are fundamentally unchanged from what they were 10, 20, 30 years ago.

also, there's other benefits to gearbox drivetrains aside from eliminating the dangly shift part at the back end of the bike.

 

[StiHacka]

If you put a copper coil on it you can pick up free energy via induction from people's cell-phones on the trail.

Gives a new meaning to "powered by Strava".

I don't need electronic shifting for any of my bikes. I've never had issues with cable actuated RDs. I could, OTOH, see how a wireless dropper linked to a shock's compression controls (full open when saddle down, climbing circuit on when saddle up in the climbing position) could simplify my routines.

 

[slimshady]

Gives a new meaning to "powered by Strava".

I don't need electronic shifting for any of my bikes. I've never had issues with cable actuated RDs. I could, OTOH, see how a wireless dropper linked to a shock's compression controls (full open when saddle down, climbing circuit on when saddle up in the climbing position) could simplify my routines.

I see a lot of Fox (or Magura) products in your future...

 

[StiHacka]

I see a lot of Fox (or Magura) products in your future...

 

[kickstand]

you sure are caught up on the details.

I think you have that backwards.

I'm not caught up on anything. 1 occurrence in 30 years of riding bikes is not enough to make me give two hoots.

You on the otherhand seem concerned about it.

 

[jonKranked]

I think you have that backwards.

I'm not caught up on anything. 1 occurrence in 30 years of riding bikes is not enough to make me give two hoots.

You on the otherhand seem concerned about it.

Definitely don't have it backwards.

If you don't give two hoots, why are you still trying to convince me that your single data point is relevant?

 

[kickstand]

I'm not sure why you're so upset about this.

I'm not trying to convince you of anything.

You have this backwards. I'm not the one advocating technology no one is developing for a reason. I'm not the one who started another thread. I simply don't have a problem with derailuers, they work fine for me.

 

[jonKranked]

I'm not sure why you're so upset about this.

I'm not trying to convince you of anything.

You have this backwards. I'm not the one advocating technology no one is developing for a reason. I'm not the one who started another thread. I simply don't have a problem with derailuers, they work fine for me.

you do realize i'm just messing with you at this point, yes?

also, risk of damage isn't the only benefit of gearboxes (over conventional drivetrains). this technology is early state and not refined enough that it can make a serious impact.

 

[jstuhlman]

I do want a special trophy.

here ya go, sweetheart.

 

[Bikael Molton]

Derailleurs have gotten sturdier, less "bangy" and a bit lower profile though... Zee shadow+ at least (what I run).

Also, the price to replace these units vis a vis the quality, compared to 2007 X0 or X9 or w/e, is some progress.

 

[jstuhlman]

concur, but i'm drunk.

 

[hitar_potar]

Um, guys, i started this thread to see what people expect of and dream about the next Shimano gravity groups, about their thoughts on what Shimano might be cooking. I didn't start it for the offtopic or the dilema regular drivetrain vs gearboxes (or sure as hell not the pics of grannies riding wheelchairs or dick-prizes). Please stop the offtopic!

automatic shifting for dh race bikes?

I've played with that idea in my mind for some time, but i think it would be more usefull in AM-bikes. In order to work it needs to be Di2, there should be a ............... (the name of the gadget on your crank that reads your cadence and power you put through your legs - i don't know it in english), and you would use a shifter not to selct a gear, but to put in your preferred cadence/ power that you would like to be putting on the drivetrain. Whether it is race runs or more comfort ones - you just up or down the number of revolutions of your pedals and the drivetrain automatically selects a gear for you that you'd be comfortable with. Something like that! But i don't think it would work on DH bikes.

 

[kickstand]

Um, guys, i started this thread to see what people expect of and dream about the next Shimano gravity groups, about their thoughts on what Shimano might be cooking. I didn't start it for the offtopic or the dilema regular drivetrain vs gearboxes (or sure as hell not the pics of grannies riding wheelchairs or dick-prizes). Please stop the offtopic!

You must be new to the internet?

 

[kickstand]

here ya go, sweetheart.

Muchas Gracias!!

 

[kickstand]

you do realize i'm just messing with you at this point, yes?

also, risk of damage isn't the only benefit of gearboxes (over conventional drivetrains). this technology is early state and not refined enough that it can make a serious impact.

You do realize I'm ok with you messing with me right?

I think that the technology is neato, I have no problem with it, I just don't think enough people are having problems or see the need for improvement over derailuers at this time to push development of the gear boxes.

Sorta like when gas is cheap no one wants to drive an Aveo. When derailuers are mostly reliable no one wants to spend the extra cheese.

 

[johnbryanpeters]

Um, guys, i started this thread to see what people expect of and dream about the next Shimano gravity groups, about their thoughts on what Shimano might be cooking. I didn't start it for the offtopic or the dilema regular drivetrain vs gearboxes (or sure as hell not the pics of grannies riding wheelchairs or dick-prizes). Please stop the offtopic!

I've played with that idea in my mind for some time, but i think it would be more usefull in AM-bikes. In order to work it needs to be Di2, there should be a ............... (the name of the gadget on your crank that reads your cadence and power you put through your legs - i don't know it in english), and you would use a shifter not to selct a gear, but to put in your preferred cadence/ power that you would like to be putting on the drivetrain. Whether it is race runs or more comfort ones - you just up or down the number of revolutions of your pedals and the drivetrain automatically selects a gear for you that you'd be comfortable with. Something like that! But i don't think it would work on DH bikes.

I still think that the pros will all be riding pink bikes by next Thursday.

 

[jonKranked]

You do realize I'm ok with you messing with me right?

I think that the technology is neato, I have no problem with it, I just don't think enough people are having problems or see the need for improvement over derailuers at this time to push development of the gear boxes.

Sorta like when gas is cheap no one wants to drive an Aveo. When derailuers are mostly reliable no one wants to spend the extra cheese.

i think we've gone brokeback drivetrain.

at this point yea the technology isn't ready for mass consumption. although it has improved, it still has a ways to go until it's a real threat to deraillers.

granted, some of the new 1x drivetrains are crazy expensive. xx1 is $750 just for derailler, shifter, and cassette.

there's some inherent issues with each that no amount of technological advancement will solve.

 

[blackohio]

you guys should dick mouth fight to see who lasts longer in this thread countering what the other guy says. See who can say "you fail to.." more than the other guy.

 

[StiHacka]

here ya go, sweetheart.

Is that the new ReDerp seatpost?

 

[Udi]

Why are there two pages of arguing about drivetrains in the DH forum, who even likes pedalling?

I think the biggest thing Shimano needs to sort out is their damn brakes. They take the crown for power and heat management, but the reliability is downright terrible (and occasionally dangerous).

I just finished a half-season in QT and the most common maintenance task (across ~18 bikes + 10 riders) was messing around bleeding Shimano brakes. Out of two bleedkits, one funnel was broken and the other stripped from how much use they were getting. Varying lever throws, levers coming to bars, fluid completely black from un-anodized internals, the same problems they've had every generation after the original M755/756 and M800 brakes.

The worst part is when people defend the issues or blame the user, that just encourages Shimano to keep selling the same junk without fixing the issues. I hope they sort it out at some point.

 

[Gary]

I'll happily pedal all day. It's braking I hate

@Udi Any of 'em on Deores?
They're the only (new) Shimano's I've got and they've been pretty good. They're not on a DH bike but they have seen plenty DH track use with no dramas and no maintenance other than hose shortening bleed. Mates have had dramas with ALL the higher end new shimanos. Coincidence? or luck?

Also. What does dirty/Blackened fluid actually affect? I've used old Avids that wouldn't physically ever flush clean by bleeding (I think small insects crawled in there and died) and not noticed any difference over clean fluid sets.

 

[johnbryanpeters]

...fluid completely black from un-anodized internals...

Please propose how un-anodized internals turn brake fluid black. Al2O3 is white...

 

[Jm_]

Why are there two pages of arguing about drivetrains in the DH forum, who even likes pedalling?

I think the biggest thing Shimano needs to sort out is their damn brakes. They take the crown for power and heat management, but the reliability is downright terrible (and occasionally dangerous).

That's why they need electromagnetic generator-brakes mounted to your Boost-Drive™ hubs that re-generate braking energy and store it in your SWAT-box. You haven't even begun to feel the boost.

 

[Udi]

Please propose how un-anodized internals turn brake fluid black. Al2O3 is white...

If you have any practical experience with this (it's something you'll notice with Shimano brakes, un-anodized Marzocchi HSCV cartridges, or something as simple as a raw aluminium frame) you'll know the wear material turns black. It could be a reaction with oils, or a reaction with other elements in the alloy that causes this. There might be some useful reading here and here.

From the first link:

Aerospace aluminum is commonly an alloy, and a formulated alkaline solution containing sodium sulfide will likely react with the alloying element. In the case of 2000-series aluminum, the main alloying element is copper. Its sulfides contribute to the formation of a characteristic nearly-black smut layer on the part surface. This likely reaction of the alkaline solution with copper follows. The black smut layer is also a spectral effect of the aluminum base metal being etched around the lesser affected intermetallic particles.

Any of 'em on Deores?
They're the only (new) Shimano's I've got and they've been pretty good. They're not on a DH bike but they have seen plenty DH track use with no dramas and no maintenance other than hose shortening bleed. Mates have had dramas with ALL the higher end new shimanos. Coincidence? or luck?

Also. What does dirty/Blackened fluid actually affect? I've used old Avids that wouldn't physically ever flush clean by bleeding (I think small insects crawled in there and died) and not noticed any difference over clean fluid sets.

Hard to say but most of the problem sets I've seen have been higher end ones too, this season they were all XT, SLX, Zee and Saint. The Saints and XTs are more problematic, possibly a function of the free-stroke-placebo adjuster. I haven't used any Deores for DH.

The blackened fluid itself isn't necessarily a huge problem (although it likely accelerates wear throughout the brake system due to particulates). The problem is that the un-anodized internals, particularly the master cylinder piston (machined) and bore (cast), will experience accelerated wear as a result of the substantially reduced surface hardness. It's only the bore that isn't anodized, the piston itself is clear anodized - but it doesn't take two to tango in this case - I've removed the piston and seen scoring and anodizing worn off. This causes tolerances to increase over time, and throw + reliability issues that increase over time. I don't think this is the primary cause of Shimano's issues (at all), but it doesn't help their case either.

Conversely, Formula brakes for example use a hard-anodized piston supported by a stationary plastic bushing on one end, sliding in an anodized bore (in a cold forged MC, no less), I've never seen any wear on these units and the fluid is always clear. Avid brakes generally use a plastic piston inside an aluminium bore, and they offer replacement pistons.

 

[Kanye West]

Udi - You've researched current models of brakes more than I have at this point (I assume). The M800's on my trail bike are starting to crap out and lose MC pressure...I think. Light/cost effective/powerful replacement suggestions? I'm also leery of the new Shimano's. Sounds like Boxxer-level maintenance schedules.

 

[Udi]

Udi - You've researched current models of brakes more than I have at this point (I assume). The M800's on my trail bike are starting to crap out and lose MC pressure...I think. Light/cost effective/powerful replacement suggestions? I'm also leery of the new Shimano's. Sounds like Boxxer-level maintenance schedules.

For cost effective with an increase in power (although possibly being a small gamble in reliability), I think your best bet would be some Deore servo wave levers, they're so cheap that if it doesn't work out it's no big loss, and potentially you'll be quite happy. I presume your old calipers are probably still fine if they aren't leaking around the pistons.

The M800s aren't very powerful, and since you like Hope, the T3E4 would probably be a reliable long term alternative, thought not cheap. Keeping with the not-cheap theme, I've just put ~200 runs on my new Formula RO-Racing brakes w/ zero maintenance or inconsistency, and they're my current favourite. Expensive though.

 

[Kanye West]

I am slightly tempted to try some Formulas again, because they can be found really cheap used - substantially cheaper than I can get the Hope's for at discount pricing.

I would have to look into parts sourcing again. Last time I tried to refurb some K18's or K24's a couple years ago, parts availability and pricing was obnoxious.

 

[Gary]

My question was answered today in the form of the most randomly inconsistent rear lever bite point and weird pumping up. Not sure why but it only started after my bike fell down a banking and stopped upside down resting against a tree.
Hoping a quick mini bleed sorts it. (the old tie lever to grip overnight and just bleed the lever next day trick)
Front as ever is sweet!

 

[johnbryanpeters]

If you have any practical experience with this (it's something you'll notice with Shimano brakes, un-anodized Marzocchi HSCV cartridges, or something as simple as a raw aluminium frame) you'll know the wear material turns black. It could be a reaction with oils, or a reaction with other elements in the alloy that causes this. There might be some useful reading here and here.

From the first link:




Hard to say but most of the problem sets I've seen have been higher end ones too, this season they were all XT, SLX, Zee and Saint. The Saints and XTs are more problematic, possibly a function of the free-stroke-placebo adjuster. I haven't used any Deores for DH.

The blackened fluid itself isn't necessarily a huge problem (although it likely accelerates wear throughout the brake system due to particulates). The problem is that the un-anodized internals, particularly the master cylinder piston (machined) and bore (cast), will experience accelerated wear as a result of the substantially reduced surface hardness. It's only the bore that isn't anodized, the piston itself is clear anodized - but it doesn't take two to tango in this case - I've removed the piston and seen scoring and anodizing worn off. This causes tolerances to increase over time, and throw + reliability issues that increase over time. I don't think this is the primary cause of Shimano's issues (at all), but it doesn't help their case either.

Conversely, Formula brakes for example use a hard-anodized piston supported by a stationary plastic bushing on one end, sliding in an anodized bore (in a cold forged MC, no less), I've never seen any wear on these units and the fluid is always clear. Avid brakes generally use a plastic piston inside an aluminium bore, and they offer replacement pistons.

OK, I read your references, and did a little more poking around. Some takeaways:

From your first reference:
"A protective oxide film of aluminum is only stable in a pH range of 4.5 to 8.5."

The pH of mineral oil is 7, so that's not likely an issue, nor would I expect it to be.

Shimano, http://www.bikerumor.com/2013/04/11/tech-speak-brake-fluid-break-down-and-implications-for-road-disc-updated/:

"...we recommend replacing our fluid as it gets dirty. This is about once a year for the most serious riders who mainly stick to the same bike and ride off road. If the fluid stays clean, like if the bike is in storage, it doesn’t need to be replaced ever."

Udi, if the wear you have observed is typical, we have somewhat of a chicken and egg problem. Is the wear due to dirty or contaminated brake fluid, or is the dirty brake fluid a result of wear? I'm not at this point convinced that anodization or lack thereof is the observed issues.

What I do hear you saying pretty clearly is that there's a higher occurrence of problems with Shimano's current brakes than those from other manufacturers. I'm not convinced at this point that anything stated points to a cause. I'd posit that if you're observing scoring and worn anodizing, especially scoring, it's most likely due to dirt getting into the master cylinder, probably during maintenance..

 

[Udi]

I am slightly tempted to try some Formulas again, because they can be found really cheap used - substantially cheaper than I can get the Hope's for at discount pricing.

I'd recommend only getting the latest ones if getting Formula (ideally RO-Racing). The old levers have lousy geometry and they've finally fixed it, plus the new design should be more durable and reliable over multiple seasons.

Formula stocks small parts in most places I've been (CA, Europe, AU), but I think buying used brakes (in general) is potentially lining yourself up for disappointment. The cheapest I've seen new is on ebay here.

My question was answered today in the form of the most randomly inconsistent rear lever bite point and weird pumping up. Not sure why but it only started after my bike fell down a banking and stopped upside down resting against a tree.

It's almost always the rears that play up. Welcome to the world of new Shimano brakes, but hopefully not, let us know if the problem re-occurs.

"...we recommend replacing our fluid as it gets dirty. This is about once a year for the most serious riders who mainly stick to the same bike and ride off road. If the fluid stays clean, like if the bike is in storage, it doesn’t need to be replaced ever."

Udi, if the wear you have observed is typical, we have somewhat of a chicken and egg problem. Is the wear due to dirty or contaminated brake fluid, or is the dirty brake fluid a result of wear? I'm not at this point convinced that anodization or lack thereof is the observed issues.

What I do hear you saying pretty clearly is that there's a higher occurrence of problems with Shimano's current brakes than those from other manufacturers. I'm not convinced at this point that anything stated points to a cause. I'd posit that if you're observing scoring and worn anodizing, especially scoring, it's most likely due to dirt getting into the master cylinder, probably during maintenance..

1. I can usually bleed a brake without pouring sand into the reservoir.
   
2. When I am in a mood to pour sand into various reservoirs, I usually don't pour it straight into the bottle of fresh mineral oil.
   
3. How is the fluid "getting dirty" in a completely sealed system? Hint: Internal wear and resultant particles. See my previous posts.
   
4. Fluid contamination is a result of oxidization and wear. This type of piston wear and fluid discoloration (heavy blackening) is visible on Shimano brakes that have never been bled or opened by the end user. Perhaps you need to let Shimano know that someone is pouring sand into their brake fluid at factory. Hint: it's not me, I usually just pour it straight into my reservoir.
   
5. I've owned virtually every single Shimano brake system from the original M755 (licensed from Grimeca) right up until current. I've also owned most other brands of brakes, and I have dissected virtually all of them (which I doubt you have, judging by your short-sighted commentary). It's pretty easy to isolate problems to their causes with some general engineering knowledge (after observation of design vs. correlating internal condition).
6. I clearly stated that this isn't the cause of the main issues with Shimano's current brakes - in fact this wear and contamination has been present since the original M755/756/800 brakes which were generally reliable. It certainly can't help their current situation either though.
   
7. It's not a chicken and egg problem in any way, unless you enjoy entertaining delusions.
   
8. I'm not here to convince you.

While I'm giving you valuable hints, here's another one: A "Lead Multi-Service Technician" (the source of your quote) is not a senior brake engineer, nor a brake engineer, nor an engineer of any description. I can guarantee there will be people on this forum with far greater experience and greater qualification on the subject at hand than said technician, and sometimes it's easy to forget that in a relatively-intelligent-but-not-quite-enough "manufacturer-knows-best" world.

 

[Kanye West]

I'd recommend only getting the latest ones if getting Formula (ideally RO-Racing). The old levers have lousy geometry and they've finally fixed it, plus the new design should be more durable and reliable over multiple seasons.

Formula stocks small parts in most places I've been (CA, Europe, AU), but I think buying used brakes (in general) is potentially lining yourself up for disappointment. The cheapest I've seen new is on ebay here.

Thanks. What usually craps out on these (when considering a used set)?

 

[johnbryanpeters]

I'd recommend only getting the latest ones if getting Formula (ideally RO-Racing). The old levers have lousy geometry and they've finally fixed it, plus the new design should be more durable and reliable over multiple seasons.

Formula stocks small parts in most places I've been (CA, Europe, AU), but I think buying used brakes (in general) is potentially lining yourself up for disappointment. The cheapest I've seen new is on ebay here.



It's almost always the rears that play up. Welcome to the world of new Shimano brakes, but hopefully not, let us know if the problem re-occurs.

1. I can usually bleed a brake without pouring sand into the reservoir.
   
2. When I am in a mood to pour sand into various reservoirs, I usually don't pour it straight into the bottle of fresh mineral oil.
   
3. How is the fluid "getting dirty" in a completely sealed system? Hint: Internal wear and resultant particles. See my previous posts.
   
4. Fluid contamination is a result of oxidization and wear. This type of piston wear and fluid discoloration (heavy blackening) is visible on Shimano brakes that have never been bled or opened by the end user. Perhaps you need to let Shimano know that someone is pouring sand into their brake fluid at factory. Hint: it's not me, I usually just pour it straight into my reservoir.
   
5. I've owned virtually every single Shimano brake system from the original M755 (licensed from Grimeca) right up until current. I've also owned most other brands of brakes, and I have dissected virtually all of them (which I doubt you have, judging by your short-sighted commentary). It's pretty easy to isolate problems to their causes with some general engineering knowledge (after observation of design vs. correlating internal condition).
6. I clearly stated that this isn't the cause of the main issues with Shimano's current brakes - in fact this wear and contamination has been present since the original M755/756/800 brakes which were generally reliable. It certainly can't help their current situation either though.
   
7. It's not a chicken and egg problem in any way, unless you enjoy entertaining delusions.
   
8. I'm not here to convince you.

While I'm giving you valuable hints, here's another one: A "Lead Multi-Service Technician" (the source of your quote) is not a senior brake engineer, nor a brake engineer, nor an engineer of any description. I can guarantee there will be people on this forum with far greater experience and greater qualification on the subject at hand than said technician, and sometimes it's easy to forget that in a relatively-intelligent-but-not-quite-enough "manufacturer-knows-best" world.

Meh - I'll resume comment if and as I find reason to disassemble my current brakes.

 

[Flo33]

Seems like I am caught by the described lever pump issue on my BR-M785 rear brake as well. I have been running the brake for 2 years now without any issue. I will give it a try and do a bleed, changed the pads about two weeks ago.

I still have a 2007 The One lying around and was wondering if the old caliper would work with the newer T1 Racing master cylinder. Regarding your comparison database I will lose a bit of power, caliper diameter decrease from 2016 24.876 mm to 2007 24 mm at same master diameter of 11.5 mm with a resulting hydraulic lev of 8.711.

I'm a bit worried though that the resulting braking power will clearly be inferior to the M785's with a hydraulic lev of 9.680. I can still recall the sensation of going into the first corner with the freshly mounted M785s and locking my front wheel for a brief moment in an off camber turn sending my flying...

Has anybody any experience with The Franken Ones?

 

[Gary]

It's almost always the rears that play up. Welcome to the world of new Shimano brakes, but hopefully not, let us know if the problem re-occurs.

TBF I haven't ever come across a set of brakes where the rear wasn't more trouble than the front.
Mini bleed done this morning found only miniscule bubbles so despite the lever feeling good I'm doubtful the issue will be solved. Unfortunately I won't be riding this bike anywhere that requires any sustained or heavy braking again for a couple of weekends so will need to wait and hope for the best.

Where do you reckon the problem stems from? Other than a longer hose and shitty routing (especially downtube/chainstay routing) and slightly more shit thrown at the caliper they should be exactly the same. no?

Anodizing/dirty fluid/piston tolerances being the culprit makes no sense when it affects one end so much more often than the other

 

[Udi]

Meh - I'll resume comment if and as I find reason to disassemble my current brakes.

Talk to me when you've diassembled 50.
Maybe next time you can just tell me the colour of another oxide.

Regarding your comparison database I will lose a bit of power, caliper diameter decrease from 2016 24.876 mm to 2007 24 mm at same master diameter of 11.5 mm with a resulting hydraulic lev of 8.711.

Has anybody any experience with The Franken Ones?

Replacement XT levers are cheap, replacement Formula Racing levers are expensive. If you got 2 years out of the XT, maybe just try them again? SLX perform identically if you want a cheaper option.

If you want to spend more though, the new levers will definitely be compatible (assuming your caliper is in good condition and not leaking). 24.876 is the RO caliper - the T1 / The One caliper has been the same since its introduction (all have 24mm diameter pistons), and the T1-Racing brake still uses 24mm pistons in the caliper. So your combination will be less powerful than the RO-Racing, but should be roughly the same as the current T1-Racing. Only minor changes have been made between yours and the current T1 caliper, none that affect power. As for power compared to the XT, hard to say (since mechanical leverage is also different) - I think you'll lose a little power, but you'll also save ~70g per end in weight so you could run larger rotors easily too.

As a sidenote, I came up with 24.876 as a circular equivalent diameter - the actual RO piston is neither circular nor oval, rather a circle with a rectangular center added.

 

[slyfink]

Where do you reckon the problem stems from? Other than a longer hose and shitty routing (especially downtube/chainstay routing) and slightly more shit thrown at the caliper they should be exactly the same. no?

you guys have waaaay more knowledge of this stuff than me, but fwiw when I was having shit tons of problems with my XT's, we replaced the hoses, and I got a full season out them before the problem reappeared on my rear brake (the front brake remains good).

I have a Mojo HD, and the hose routing is kinda dumb in that it forces the hose to flex a lot at the linkage. I thought that might have contributed to the problem.

 

[kickstand]

my zee's that were plagued with troubles on my DH bike have been flawless on my fatbike. I hypothesize that since the fat bike is slow and miserable to descend on that it actually doesn't bounce around enough to dislodge the bubble that can't be bled out of the system. Or, I finally got a good bleed on them? Or my fingers are too number to tell that I've got an inconsistent bite point?

 

[StiHacka]

Has anybody any experience with The Franken Ones?

So far I've been happy with Saint M820 levers / Magura MTS calipers but I have those Frankenbrakes on a trail bike that is not seeing as strenuous braking as a DH bike. Zees definitely felt worse in the pump-up issue department.

 

[Gary]

Yeah... my routing runs straight from the downtube to along the chainstay so as minmal hose flexing as possible. there'll be way more from turning the bars and I intentionally run my rear hoses long enough to X-up so even there there's not a lot of flexing. Brakes are 6months old. 400miles of use (apart from one day at Ft William half of that's climbing). interesting that the hose was your issue. bike's short travel Solpestyle bike but I use it for ride to the top DH.

I can live with less than perfect brakes but I may as well make use of the 2yr warranty if it turns out to be a constant PITA.