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  1. #1
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    Marta piston problem, or design?

    I've just recieved my Marta equiped bike this Tues, and noticed I had much better pad clearance on the front, than the rear.

    After pulling the pads out of the rear brake, I noticed the piston on the outboard side can be pushed back until it sits flush with the caliper, while the inboard side feels like it bottoms out just before it can sit flush. The inboard side pad tends to run a bit closer to the rotor, and frequently rubs, no matter how true the rotor.

    I tried the one-at-a-time piston protraction, then pushed them back in.

    I noticed the caliper body is thicker material laterally, on the outboard side, but it seems to me they would have designed them so the pistons retract fully flush on both sides.

    I just got this bike and have only made some pad bed-in runs at a local park on a paved path. I really don't want to have to do a bleed, or anything that would involve opening up the hydraulics.

    I was counting on getting in several months of riding, then having a LBS, recommended by a fellow Marta owner for excellent service and pricing, bleed them, rather than paying twice as much just for the bleed kit, and being green at the procedure.

    Once again, the front has great spacing on both sides. What caused me to notice the rear in the first place, was a line that was scored in the rotor, which I thought was just a bit of metal from the pad, or something stuck in it.

    After sanding the pad and the rotor, I noticed the inboard piston wouldn't seat flush, you can see the beveled edge of it sticking out, unlike the other side, which can be pushed in all the way flush.
    Last edited by Gnarlygig; 06-12-2004 at 07:06 PM.

  2. #2
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    Is the entire inboard piston unable to retract flush or just a portion of it?
    I once had a caliper where only the lower part of the piston wouldn't retract and it was a seal defect. If its the entire piston then it should be OK and here are my recommendations:

    1- reactuate the pistons. Yeah, I know you did it, but do it again. Make sure the pads are out when you do it and don't extend them 100% fully or you may get hydro lock whick sucks and then you'll need to bleed.

    2- With the inboard piston extended during reactuation rub a tiny bit of mineral oil or a lightweight shock oil on the piston

    3- Just add another set of spacers to the caliper so that the entire caliper is more inboard.

    4- do the micro-adjust trick. Do you know this one?

    It does not sound like you need a bleed & I highly discourage you from going down that road. Once setup properly you shouldn't need to bleed that brake for a long time provided that you change the pads when appropriate.
    “Life is like riding a bicycle. To keep your balance, you must keep moving.”

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  3. #3
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    No, I don't think they need bleeding either, The levers don't...

    Quote Originally Posted by The Squeaky Wheel
    Is the entire inboard piston unable to retract flush or just a portion of it?
    I once had a caliper where only the lower part of the piston wouldn't retract and it was a seal defect. If its the entire piston then it should be OK and here are my recommendations:

    1- reactuate the pistons. Yeah, I know you did it, but do it again. Make sure the pads are out when you do it and don't extend them 100% fully or you may get hydro lock whick sucks and then you'll need to bleed.

    2- With the inboard piston extended during reactuation rub a tiny bit of mineral oil or a lightweight shock oil on the piston

    3- Just add another set of spacers to the caliper so that the entire caliper is more inboard.

    4- do the micro-adjust trick. Do you know this one?

    It does not sound like you need a bleed & I highly discourage you from going down that road. Once setup properly you shouldn't need to bleed that brake for a long time provided that you change the pads when appropriate.
    ...feel mushy at all, and I'm pretty sure I didn't protract either piston too far, as the lever feel and spacing is the same with the wheel in, as it was before.

    I don't think shimming is necessary either, as the rotor is already centered as good as it can be, given the shim thickness available to do so with.

    Jimi emailed me back saying this, regaurding the pushing in of the piston:

    "If you are still getting a slight drag now then do this. First identify which side piston you are getting the drag from. Pull the brake lever until you hit the engagement point and then hold it. Now take a flat blade screwdriver and place it between(opposite side from the dragging piston) the back of the pad and caliper body and gently twist the rotor and then let go of the lever blade."

    With this method I'd be concerned about damaging the caliper, pad, or piston head, as the only place to get proper centered leverage, is at the center of the pad, where the piston is.

    I suggested to Charles via email, that I will try enhancing my previous leveraging technique, of using a quarter over the piston head, and pushing a screwdriver blade aginst it (without prying on the caliper body), by using two quarters instead, one over each piston, and twisting something large enough between the quarters to try and seat the inboard one.

    At least this technique will pretty much gauantee no damage to the brake parts, and the quarters slightly overlap the piston head to ensure they won't be pushed in beyond flush, if that even IS possible.

    I think I read about the microadjust technique from you or Mike T, which I seem to recall involves fine tuning the centering, by holding the rotor (I use nitrile gloves) against one pad, then the other, until you achieve perfect centering, or am I mistaken?

    I'll definately try lubing the inboard piston this time, after protracting it, to see if it helps pop that baby all the way in. The piston doesn't appear to be cocked at an angle, though it's really hard to tell not being able to see it's entire circumfrance.

    I'll check it again right now...

    ...upon further investigation, it appears the front portion of it may be sticking out slightly farther than the rear. I'll try putting the pressure slightly forward of center next time I try pushing it back in.

    Once again, centering is NOT the issue, but rather overall clearance.

    Thanks Skweak.

  4. #4
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    I just use a plastic tire lever when I'm reactuating the pistons. Doesn't damage anything.

    I think Jimi's tip is just a variant of the microadjust trick. But that's for centering.

    I'm not 100% certain that I understand your problem, but if its properly centered then adding a shim should get you the requiste clearance. Don't worry about having the rotor dead-aligned down the middle of the caliper.
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    OK, I'm making some progress, and narrowing down...

    Quote Originally Posted by The Squeaky Wheel
    I just use a plastic tire lever when I'm reactuating the pistons. Doesn't damage anything.

    I think Jimi's tip is just a variant of the microadjust trick. But that's for centering.

    I'm not 100% certain that I understand your problem, but if its properly centered then adding a shim should get you the requiste clearance. Don't worry about having the rotor dead-aligned down the middle of the caliper.
    ...the problem.

    I got the inboard piston to go in flush finally, using some Stanchion Lube, and a quarter over each piston, and a little combination open end/closed end 8mm wrench to leverage it. The wrench is the type that has a little bend to the closed end side, which worked perfect to pry between the quarters.

    As it turns out, I was right that the caliper is already centered as well as it can be given the .2 mm, and .4 mm shims available. This I know because I went to my LBS and purchased 4 of each size, and tried every combination to space the caliper. There were four .2mm shims per bolt in there from HH, I ended up replacing them with two .4mm shims per bolt, just to simplify, and avoid misplacing or bending the little ones.

    I then took a standard thickness (about .3mm) business card, cut it lengthwise, and put each half between the pad and rotor, to make sure the pads would come equal distances to the rotor.

    This worked on paper, so to speak, but when I pull them out and squeeze the lever, the inboard pad still comes to rest much closer to the rotor, after barely retracting at all.

    I don't think it has anything to do with the seal sticking, because that piston now moves in and out pretty freely, from working it in and out a few times after lubing it.

    Could it be they put the wrong durometer seal on that half of the caliper or something, just doesn't make sense to me.

    It's also got me wondering if rear disc lines being longer, just have weaker retraction, and less clearance because of it.

    As far as I'm concerned, it's certainly not acceptable to recenter, to make up for bad retraction of one piston, and end up with much less clearance because of it. The way it is, there's no where near the clearance the front has.

    All along I was worried that discs in general would cause this kind of grief for me, being used to the pad to rim clearance of Vs.

    I'm now beginning to wonder if it's either a finicky tendency of the Maguras, or needing to break them in.

    From my understanding, the pads on these retract by means of both fluid returning towards the master cyclinder, and seal flex. Doesn't this mean there's a fine line between the pistons sliding well enough to not stick, and sliding so well as to not allow the seal to grip, and flex back into position? Perhaps this is why this system is called finicky by many, I don't know, but I'm hearing more people say it all the time. There's certainly more to deal with than a little shim handling, THAT part was very easy I thought.

    So far though, I can't say I'm liking it, and missing a lot of riding because of it. I'm certainly NOT in the mood for making up any giddy frat house rhymes to get in the "cult" at this point either, esp when they don't even mention how deep the pads are supposed to push back in. Personally, I think my method of doing so is more efficient and safer as well.

    None the less, I'll take a break from it for now, and see if I can get a hold of Jimi on the phone tommorow. At least if it's something related to bleeding, I know the pistons are going in all the way, and the caliper is centered. That way any shop that has done the bleeding procedure can get the lines set up right, if they're not.

    It may be a defective caliper like the one you refered to, but for perhaps different reasons.
    Last edited by Gnarlygig; 06-14-2004 at 01:45 AM.

  6. #6
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    Does the pad touch the rotor when you spin the wheel or not?

    If not, then don't worry about it and just ride it. The small amount of unequal spacing is irrelevant.

    If so, and it's minimal drag, then, again, just ride it. A very small amount of drag is acceptable when new and should disappear after a ride or so.
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    With the caliper centered as it should be, the same spacing....

    Quote Originally Posted by The Squeaky Wheel
    Does the pad touch the rotor when you spin the wheel or not?

    If not, then don't worry about it and just ride it. The small amount of unequal spacing is irrelevant.

    If so, and it's minimal drag, then, again, just ride it. A very small amount of drag is acceptable when new and should disappear after a ride or so.
    ...as HH sent it out with, it's got about the normal amount of clearance on the outboard side (pretty close to 1/2 mm it looks like), but touching all the way around on the inboard side, making a fluttering sound from the wavy rotor all the way around.

    Basically, I'm lacking 1/2 mm of clearance on the inboard side. With a flick of the wheel, I get about 4 revolutions, and that certainly isn't all new King rear hub seal drag.

    I can't help but think, that if one piston is so tight now, by the time I break them in with a fair amount of riding, it will still be tighter than the others, because they're going to break in too. Doesn't that mean that it will still not center properly? Seems to me, it should work as well as the front, out of the box, after all, they're supposed to check the piston action at the factory before they ship them out aren't they?

    I can rotate the front and clamp the lever, over and over again, and it always has the same clearance, with equal spacing.

    If I end up having to reshim the rear inward with another .2mm spacer, for lack of alternatives through Magura, I hope that pison won't take long to loosen up.
    Last edited by Gnarlygig; 06-14-2004 at 02:06 AM.

  8. #8
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    You've already done a variation of what I'm suggesting, but try this...


    Push the rotor towards the inboard side and hold it there while pulling on the brake lever a few times. Check the spacing and repeat again as necessary. It's tough to do on the rear without a second person but you get the idea.
    If that doesn't work then place a rubber band around the lever so that the pads are engaged. Now push the rotor over towards the inboard side.

    If that doesn't do it then I'm out of ideas and will definitely refer you to Jimi.
    Let me know how it goes. I agree, 4 revolutions of the wheel is not acceptable.
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    OK, here's the latest, from further study. Although the piston...

    Quote Originally Posted by The Squeaky Wheel
    You've already done a variation of what I'm suggesting, but try this...


    Push the rotor towards the inboard side and hold it there while pulling on the brake lever a few times. Check the spacing and repeat again as necessary. It's tough to do on the rear without a second person but you get the idea.
    If that doesn't work then place a rubber band around the lever so that the pads are engaged. Now push the rotor over towards the inboard side.

    If that doesn't do it then I'm out of ideas and will definitely refer you to Jimi.
    Let me know how it goes. I agree, 4 revolutions of the wheel is not acceptable.
    ...appeared to be aligned straight after pushing it in flush, it did look like the front portion stuck out more before pushing it in, as mentioned previously.

    After talking to Lonnie on the phone (Jimi's away for a week), something he said reminded me of a possible piston alignment problem.

    Getting the piston to go in all the way flush had me thinking all I had to do was check the shimming for possible need of recentering. Upon trying different shim configurations, I first did the trick where you "float" the caliper with the bolts loose. When I did this, the caliper would tilt slightly, as the pads touched the rotor, taking it out of what was good alignment with the rotor. This told me, and Lonnie agreed, that the piston is not only sticking, but extending crooked.

    He said he could either send out a new caliper, or I could send in this one and they could take a look at it. I asked if he could pick this one up on call tag, then send me the new one, as a compromise, to which he agreed.

    As there is only 1 shop in the entire Puget Sound area he could verify to be trained by their techs, and very far away from me, invovling an expensive ferry boat ride as well, he agreed, after some persuading, to send me a bleed kit with the caliper, so I could install it myself.

    Whatever you do Skweak, please don't desert me, I'll no doubt need to touch bases with you again!

    I did bleed the HS33s I had on a previous bike myself, but these are quite a bit trickier.

    Lonnie said he would send me some of his personal tips too, and I asked him to hook up the new caliper and test it out, to make sure it's working properly, to which he assured me he would.

    Thanks Lonnie, you saved the day for me!

  10. #10
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    Sorry to hear you are having problems.

    I sold my marta's as a result.

    I think the marta's have amazing weight, power, and the design is quite sano. Furthermore the support from Jimi and Lonnie is tops in the business. That goes a long way.

    Conversely, maybe due to the weight, maybe due to other factors like my mechanical ability (though I've worked in a shop in the past etc), I found they just were finnicky. Between centering things up, only to find they aren't centered, and constant need for bleeding them, which is a pain in the butt. I sold mine and went back to hayes.

    I also found they faded more than my hayes on longer decents. I'm 200+ though. I know many have had great luck with maggies though so it might just be me.

    I hate spending time working on my bike when I don't need to. Don't mind tune up's here and there etc. But working on those brakes all the time was a pain.

    They Hayes have their faults (bleed process also a pain) use DOT fluid (though this I feel helps with consistent performance). Huge levers and shortening lines is a pain.

    The flip side is, once hayes brakes are set-up, they stay that way for a good long time.

    I'd love brakes that saved weight and had adjustbable engagement etc. The new shimano stuff looks very nice. That said, I want consistency from my brakes, and Hayes still fit the bill.
    Last edited by Green Giant; 06-14-2004 at 01:18 PM. Reason: sp
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    I'm guessing part of the problem with the type of issue I had,...

    ...is due to the Martas being made in much larger volume than their other models, and made with a molded plastic piston as well. Between the volume of production, the steamlined design, and the piston being molded, rather than machined, I'm not surprised some of them come out bad, but their CS more than makes up for it I think.

    As far as the bleeding goes, I think a lot of that may be improper technique, but the Magura tech manual could be written better. The O rings they say to use on the bleeder insert, for example, often causes poor sealing during the bleed process.

    Other reasons may be that some are stressing them to their limits. A plus 200 lb rider, is capable of generating much more heat in the system, than a rider 150-190 lbs. With that heat expansion, comes contraction thereafter, and more chance for contamination. What I'm saying is, all brakes need bleeding eventually, usually about once a year, overstressing them may cause them to need it much more often, but again, I think improper bleeding is commonly the case.

    There's local guys here in the wet NW that run the Martas and swear by them, often getting 1 1/2 years of use before bleeding.

    One last note: A good indication of some of the misconceptions and bad impressions of the finickiness of these brakes, is the fact that there's not a lot of shops really trained by the Magura techs, in their seminar program.

    Only one shop in the entire Puget Sound area, for instance, could be verified by Magura as a definate Magura trained shop.

    What I'm saying is, it's one thing for customers and shops to sit back and say Martas are too finicky to bother with, quite another to learn the actual tech training, then speak on the subject after the proper technique is learned, and used in practice. After all, the name Hayes, Avid, and Shimano have built for themselves, sell product well, and that's what drives many shops to say the things they say about other products. They just don't want to risk "unhappy campers", and many customers do voice their opinions based on what their friends tell them, it doesn't mean what they hear and say is correct information.

    I would go so far as to say 90% of the need for Magura tech training, is due to the need for specific knowledge of proper bleeding.

    Anyway, with that being said, I'm looking forward to giving an unbiased, and trail tested review on the Martas the right way, after I get the problem solved, and Magura's CS is certainly doing their part with that so far. Can't say I've heard good things about Hayes CS, but I can't speak from personal experience.

    ALL brakes have some sort of problems that need to be dealt with, and ALL have some sort of defect rate. I don't feel it's fair to judge them by the small percentage of misshaps that occur. Judging from the way my front brake works, the rear will be just fine when I get one of the many normally operating ones.
    Last edited by Gnarlygig; 06-14-2004 at 05:52 PM.

  12. #12
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    Quote Originally Posted by Gnarlygig
    Whatever you do Skweak, please don't desert me, I'll no doubt need to touch bases with you again!
    I got nowhere else to go

    Lonnie's a great guy. Jimi is actually in your neck of the woods; up in Vancouver this week.

    Before you even think about bleeding I implore you to familiarize yourself with the Magura Cult homepage. Mike T. has compiled a set of instructions that shames the Magura tech manual. You may not get the bleed right on the first attempt, but it really isn't that hard. And I agree that once bled properly they won't need maintenance for quite some time. I haven't touched mine in quite some time except for pad changes.

    And please, no more negative references to the cult and our giddy rhymes. On old MTBR there used to be a lot of us out there, now it seems like its just me & Mike T. And I'm a poor stand-in for the grand pooh-bah himself. Any more negative comments about the cult may result in you never learning the secret handshake.
    “Life is like riding a bicycle. To keep your balance, you must keep moving.”

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  13. #13
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    Doug-E Fresh...

    Gnarly beat me to the punch. I certainly can't argue that you had your problems and I'm glad you're happy with the Hayes. But once properly bled, they stay bled, and remain hassle free as long as any other brake I've come across.

    Are you really surprised that you noticed fade going down long descents?
    Marta was not meant to take the Green Giant down long hills. That's what Marta's cousin Louise is for. Comparing Marta to the Hayes is really not apples to apples.

    And as for your bleeding technique...well, you are a Spartan
    “Life is like riding a bicycle. To keep your balance, you must keep moving.”

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  14. #14
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    No question

    I knew that I might give up a bit of power and get some more fading with the Marta's. Conversely, both have a dual piston design and 160mm rotors.

    While I hate using DOT fluid, I'm semi-convinced that it does resist fading a bit more. Don't get me wrong, my Hayes still fade at times but not as bad.

    As for the bleeding technique. Mine wasn't perfect, but regardless it is a bit more involved than many other hydraulics (I hate doing my Hayes also, but it's a bit less precise).

    I did have some Louise years back (circa 99), I found they faded also but I know fluids have gotten better since then.

    Ultimately, there is no perfect disc brake yet. Heck, the Avid mechanicals when combined with the ultimate levers may still be my favorites for consistent trouble free performance.


    Hopefully the mfg's keep pushing each other and that competition is good for all of us. I'd love for Hayes to come out with something close to the marta's weight and looks, with Hayes consistency, Avids new lever adjust (and lever shape) etc. Oh yea, and a trouble free and easy bleed system.
    "The thing is, Bob, it's not that I'm lazy, it's that I just don't care."

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    OK Sweak, I guess I did come off sounding a bit pompous,...

    ...and quite frankly, after rereading my post, I'm surprised the T man didn't come on board just to pummel me with his rhetoric!

    I'm sure he's waiting until my fledgling attempt at cultdom to do so, but then again, being the youngest of 5 boys growing up, I'm a bit used to it by now!

    No more cult cracks, I promise, and if you and Mike ever make it to my neck of the very thick, wet, and gnarly woods, I'll not only show you some great routes I know, I'll pay back your kindly words of wrenching wisdom with a sixpack each!

    Sometimes the best suds after a day in the dirt is the kind you put in your tummy, rather than on the bike!

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    Quote Originally Posted by The Squeaky Wheel
    Before you even think about bleeding I implore you to familiarize yourself with the Magura Cult homepage. Mike T. has compiled a set of instructions that shames the Magura tech manual. You may not get the bleed right on the first attempt, but it really isn't that hard.
    Exactly! I just got a set of Marta SLs installed last week and I followed the Cult's directions to the 'T' and the bleed was simple, painless and effective.

    Having bled several other brakes (Hope C2s, Hope Minis, Hope Mono Minis, Formula B4s, Formula B4 SLs, Formula B4 SL+ and Shimano XTR/XT), I felt very comfortable with the Martas.

    Once the lines were cut, I started and finished the rear bleed without a single issue. As brakes go, the Martas rank amongst the easiest to bleed.

    Simply position the rear caliper so the hose connection is at the highest point and push the fluid from the caliper to the master-cylinder (extract excess fluid in the 2nd syringe) and then pull the fluid back into the caliper's syringe while adding the excess fluid back into the master-cylinder's reservoir. I repeated this a couple times until no air bubbles were seen. I did not use the rubber o-ring on the fitting for the caliper's syringe.

    Once the caliper's syringe was nearly empty, I then slowly pulled the lever (15-20 times) to push fluid back down the caliper. No air bubbles were seen.

    I then gently put the reservoir membrane and cap back on and gently pressed the caliper's syringe to expel any air bubbles that may have been trapped in the reservoir under the membrane. While still pushing on the syringe, I tightened-up the reservoir screws....man, those screws are tiny!

    Lastly, I removed the caliper bolts and re-installed the pads and positioned the caliper on the rear rotor and gently pushed the caliper's syringe. Once done, I removed the caliper and pads, and then removed the bleed syringe and re-installed the bleed valve. I then re-installed the pads and positioned the caliper over the rotor....perfect alignment! Now, the ultimate test....I grab a handful of lever and give a nice tug....wow! Beautifully crisp and solid with perfect engagement point! And, dead quiet!

    The front brake installation was a mirror of the rear and resulted in a similarly feeling brake.

    I then took my bike out for a quick rip around the neighborhood, which includes some nice fast, twisty singletrack. I was simply amazed at how beautiful these brakes felt.

    It is still too early to comment on the brake's power, modulation, durability, reliability, pad-wear, noise, etc., but all signs are pointing to the Marta SL as being a definite contender for my personal favorite brake, which is currently the Formula B4 SL (and B4 SL+).
    Ride Hard,
    Mike B. (MCM# 7.77)
    http://www.one-speed.com

  17. #17
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    Well done Mike. Sounds like perfect technique.
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    The Martas are designed to be lightweight and as such have much smaller pad contact surface than most other brakes. The brake track on the Marta is closer to the old Shimano_XT 4 pot but with only 2 pot. The Louise is a much more comparable to_Hayes. The new 04 Louise have all the good features of the Martas (one piece calipers, wavy rotors, awesome customer service) but minus the weight weenie part. I'm not saying you should dump your_Hayes. I just think comparing to Marta is a bit unfair.

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    Sounds like you nailed the bleed technique 1spd M, thanks for...

    ...the confidence booster.

    I'm taking it then, that you have just as good clearance and centering in the rear, as in the front?

    I would like to add that one of Skweak's older posts on Marta bleeding really helped me visualize what the procedure would entail, when he mentioned securing the syringes in a steady, upright position was necessary to keep things spill, and air free, as well as simple.

    I've got no workbench with the limited space I have, but I think with my repair stand at the right height and rotation, I can keep the hydraulic line vertical, the bike's tire against the floor, and the syringes strapped or zip tied to the bars and frame somehow maybe, with a Park bar stabilizer strapped in place too. I'll definately be doing it with the pads removed as well, just in case. That way there won't be any chance of things moving.
    Last edited by Gnarlygig; 06-16-2004 at 02:46 AM.

  20. #20
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    Take those pads out and hide them in the other room.
    there's no need for them to be anywhere need the bleeding apparatus until the very end when you place them back in the caliper, put the rotor between them and push fluid with the syringe so that the pads engage. This ensures maximum fluid in the system. Then carefully remove the pads, unscrew your bleed syringe and put everything back together. Clean the rotor & caliper with copious amounts of isopropyl.
    “Life is like riding a bicycle. To keep your balance, you must keep moving.”

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    Have you used a disc tab facing tool (Magura Gann-o-Mat, Hope Spot, etc.) on your fork and rear triangle disc tabs? If you bought the frame/fork from Charles, this was likely done for you and the paragraphs below might be irrelevant.



    If not, it would be worthwhile trying it. In thinking about your problem, if your tabs are not aligned properly and the pistons are extended until the pads contact the rotor, they may become jammed on the way back into the caliper.

    Try to visualize that your caliper is slightly misaligned with the rotor. The pistons are flush with the caliper. As the lever is pulled and the pistons extend, they are extending parallel to the caliper's piston holes, which is normal. But, once they contact the rotor (which is slightly skewed) and pressure is exerted, the pistons may twist slightly in the caliper. Once the lever is released and the pistons are allowed to retract, they may bind upon trying to return to their original position.
    Ride Hard,
    Mike B. (MCM# 7.77)
    http://www.one-speed.com

  22. #22
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    One of the many reasons I bought from Hammerhead, is that...

    ...they understand fully the need for tab alignment, use the the Gnanomajig tool, and even rent it out. It turns out the rear did not need to be faced, as is quite often the case with a quality frame.

    I do think though, that although they aligned the rear caliper well, they could have checked the piston action on the rear caliper better.

    Having to start out brand new with half as much clearance as you're supposed to have, and position the caliper off center because of one piston not working properly, is just not acceptable to me. I'm sure many would feel the same way.

    My problem is just the opposite of what you're referring to, in that the caliper aligns better bolted down, than floating with the lever applied. This can only mean that the piston itself is misaligned, NOT the caliper.

    I may be new to discs, but I've driven a vehicle with them for many years now, and the concept of proper alignment and clearance is something I understand better than some are giving me credit for.

    I know full well what happens to disc brakes that are run in conditions that aren't up to spec. Under such circumstances, they don't just "break in", as some have suggested, they get worse.

    Being that brakes are about the most significant component on a bike regaurding safety, I would think they would be checked better at the factory and dealership, before being sent out to us mere "end users".

  23. #23
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    Quote Originally Posted by Gnarlygig
    ...and quite frankly, after rereading my post, I'm surprised the T man didn't come on board just to pummel me with his rhetoric!

    I'm sure he's waiting until my fledgling attempt at cultdom to do so, but then again, being the youngest of 5 boys growing up, I'm a bit used to it by now!

    No more cult cracks, I promise, and if you and Mike ever make it to my neck of the very thick, wet, and gnarly woods, I'll not only show you some great routes I know, I'll pay back your kindly words of wrenching wisdom with a sixpack each!

    Sometimes the best suds after a day in the dirt is the kind you put in your tummy, rather than on the bike!

    Oh I'm sitting here listening to you two comedians. Yeah I caught you dissin' my Cult but Louie with The Bat was on vacation this week so you're gonna be able to pedal with both legs for a while longer.

    At least you're keeping your sense of humour (hey I'm in Canada eh!) through all this and you're in good hands (Squeak & Lonnie) so I've been keeping my trap shut. Just about everything *I* know is on my Culticulate pages anyway. The latest info gets put there.

    Most people have usually progressed to name calling and threats by this time - both of which never solve much. Work with Lonnie and I'm sure if it takes new parts to make you happy then new parts it will be.

    The Squeak said -
    ".......no more negative references to the cult and our giddy rhymes. On old MTBR there used to be a lot of us out there, now it seems like its just me & Mike T. And I'm a poor stand-in for the grand pooh-bah himself. Any more negative comments about the cult may result in you never learning the secret handshake."

    Yeah giddy rhymes are meant to prevent us from taking ourselves too seriously. You're a great stand-in for the grand pooh-bah (huh I thought I was the ONGO?) and many times I sit back and go "I can't improve on Squeaks answer" so I don't chime in. You've had waaaay more bleeding experience and Jimi contact than I so you're the best present resource for tech info at the moment. I have a feeling that One Speed Mike will be pushing you soon ;o)

    See y'all later.

    Mike T. (mcm # 717 & ONGO)
    Mike The Bike's home wheelbuilding info - dedicated to providing Newby wheelbuilder information and motivation.

  24. #24
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    Quote Originally Posted by 1speed_Mike
    Exactly! I just got a set of Marta SLs installed last week and I followed the Cult's directions to the 'T' and the bleed was simple, painless and effective.

    Having bled several other brakes (Hope C2s, Hope Minis, Hope Mono Minis, Formula B4s, Formula B4 SLs, Formula B4 SL+ and Shimano XTR/XT), I felt very comfortable with the Martas.

    Once the lines were cut, I started and finished the rear bleed without a single issue. As brakes go, the Martas rank amongst the easiest to bleed.

    Simply position the rear caliper so the hose connection is at the highest point and push the fluid from the caliper to the master-cylinder (extract excess fluid in the 2nd syringe) and then pull the fluid back into the caliper's syringe while adding the excess fluid back into the master-cylinder's reservoir. I repeated this a couple times until no air bubbles were seen. I did not use the rubber o-ring on the fitting for the caliper's syringe.

    Once the caliper's syringe was nearly empty, I then slowly pulled the lever (15-20 times) to push fluid back down the caliper. No air bubbles were seen.

    I then gently put the reservoir membrane and cap back on and gently pressed the caliper's syringe to expel any air bubbles that may have been trapped in the reservoir under the membrane. While still pushing on the syringe, I tightened-up the reservoir screws....man, those screws are tiny!

    Lastly, I removed the caliper bolts and re-installed the pads and positioned the caliper on the rear rotor and gently pushed the caliper's syringe. Once done, I removed the caliper and pads, and then removed the bleed syringe and re-installed the bleed valve. I then re-installed the pads and positioned the caliper over the rotor....perfect alignment! Now, the ultimate test....I grab a handful of lever and give a nice tug....wow! Beautifully crisp and solid with perfect engagement point! And, dead quiet!

    The front brake installation was a mirror of the rear and resulted in a similarly feeling brake.

    I then took my bike out for a quick rip around the neighborhood, which includes some nice fast, twisty singletrack. I was simply amazed at how beautiful these brakes felt.

    It is still too early to comment on the brake's power, modulation, durability, reliability, pad-wear, noise, etc., but all signs are pointing to the Marta SL as being a definite contender for my personal favorite brake, which is currently the Formula B4 SL (and B4 SL+).

    A nice, simple, fat-free set of bleeding instructions MB! Great stuff. But did I expect any less from an engineery type?

    If I can ever find the time (early retirement's sounding better all the time) I'll check your writeup against what's on my pages and change things as necessary.

    Mike T. (mcm # 717)
    Mike The Bike's home wheelbuilding info - dedicated to providing Newby wheelbuilder information and motivation.

  25. #25
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    Quote Originally Posted by Mike T.
    A nice, simple, fat-free set of bleeding instructions MB! Great stuff. But did I expect any less from an engineery type?
    ERTW!


    Quote Originally Posted by Mike T.
    If I can ever find the time (early retirement's sounding better all the time) I'll check your writeup against what's on my pages and change things as necessary.

    Mike T. (mcm # 717)
    I think you'll find that my bleeding steps, which I've summarized, are a paraphrased version of the steps on the Cult site.
    Ride Hard,
    Mike B. (MCM# 7.77)
    http://www.one-speed.com

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