Results 1 to 14 of 14
  1. #1
    banned
    Reputation:
    Join Date
    Jan 2004
    Posts
    1,088

    Quick breakin technique for sticky Marta pistons?

    I just wanted to share with you what may be an effective quick breakin technique for sticky pistons on your Martas.

    I tried the lube the piston one at a time after protracting/retracting them, and after seeing barely any daylight on only a portion of the pads per side, even after one ride. I decided to brainstorm to see if I could speed up the process a bit.

    I reasoned that even during riding, with them retracting only about what appeared to be .1 - .2 MM per side, but still not totally drag free, they weren't getting enough range of motion in and out to necessarily free them up in 2 or 3 rides.

    I thought if I could just put something between the pistons, with the pads removed, that would allow them to protract a fair amount, yet help push them back in, it would give them a lot of movement, and with numerous pumps of the lever, resting one hand at a time, I might free them up some.

    I went back to the 2 quarters trick that I managed to push the stuck piston in with on the previous caliper (which went back to Magura for inspection), between which I stuffed the smaller diameter portion of an Oury grip (the inner end's ribbed part) that I cut off to make them Grip Shift length, which fit in snugly with two thicknesses of the material. This acted nicely as an elastomer spring, allowing me to pull the lever all the way to the bar, while it helped push them back in almost all the way.

    After many pulls with each hand, I put the wheel back in, didn't notice any improvement, then tried the routine again. This time I was able to see daylight across the entire surface of each pad, after microadjusting and pulling the lever. I also reshimmed towards the outboard side, because the outboard piston kept moving the rotor inward slightly with each pull of the lever, and was always landing closer to the rotor after retraction. Microadjusting it was not helping, as it would lose it's centering.

    I still see the rotor move inward slightly, with each pull of the lever, which is odd, because the outboard piston was slower to retract, but appears quicker and/or stronger in protracting. None the less, I'm now seeing daylight across the entire surface of each pad, not .5 MM of it like there should be, but I am much more confident now that they will indeed breakin from riding, and/or Gnarly's speed break in technique!

    I have just one question, and a suggestion. Is it normal and/or acceptable for the rotor to move to one side slightly while disc brakes are breaking in? Also, if you try this method, I highly recommend you keep a close eye on the material you use for a spring, and as well, rubber band it in place, so it will not slip or fall out of the caliper. Mine slipped a bit the second time I did the routine, and one piston protracted quite a ways, but fortunately not enough to cause a problem.

  2. #2
    Bodhisattva
    Reputation: The Squeaky Wheel's Avatar
    Join Date
    Dec 2003
    Posts
    9,515
    Gnarly,

    You are definitely one of the most analystical folks on this board. That's cool.

    What you're doing is just a variation of the reactuation/microadjust trick.

    Don't worry about the piston deflecting slightly to the side. It's OK. And expect them to warp a bit with time. That's easily corrected by bending it back into shape with your hands or a set of channel locks.

    Glad you're digging them.
    Life....the original terminal illness

  3. #3
    banned
    Reputation:
    Join Date
    Jan 2004
    Posts
    1,088

    I just tried going through that routine once again, and...

    ...see now what the problem is. The inboard side piston appears to be sticking quite a bit more than the outboard one, just like the previous caliper did. Also, the solid feel of the lever after my bleed, is only in the sense that it's air free, and fully topped off with fluid. It lacks however, the solid thunk at the point of rotor contact due to the outboard piston being dominant, and bending the rotor, much like Vs bend rims if they're not spring balanced. The front contacts evenly on each side, with no rotor pull.

    What you said about the rotor pulling to one side to the point of warping eventually really freaks me out. That doesn't sound like good working brakes at all to me. I could see how a dominant piston could also lead to premature wear on that pad.

    Sorry to sound anal Squeak, but I feel I have some legitimate concerns here. Once again, why consistent problems, of the exact same type on the rear, but the front is perfect?

    I'm going to contact Lonnie again, and ask him if he tested this caliper at all like he said he would. I see no evidence of it even having been taken out of the bag, and it looks like there's been no fluid in it.

    I know from bad experiences with disc brakes on cars, if one side drags consistently and the other has a domnant piston, you get more problems than just premature warping, you get excessive heat and poor braking performance.

    Disc brakes should not warp by design. That should only happen if you do stops from high speed, or ride them too much, or have too much load/weight on them. This the service manager of the shop agreed with when I had my brakes done right.

    I'm beginning to think this is going to take a trip out to the Olympic Peninsula, to the only shop in the Puget Sound area dubbed certified and trained in Magura brakes, to prove to Magura that there is something odd with some of their rear caliper stock.

    The fact that there's no sign of this caliper having been tested as promised, makes me wonder if they already know that.

  4. #4
    Bodhisattva
    Reputation: The Squeaky Wheel's Avatar
    Join Date
    Dec 2003
    Posts
    9,515
    I dunno, but rotors warp. usually from heat & use. Really, it's no biggie.

    Have you tried removing the pads and holding the non-sticky piston flush against the caliper body so that it doesn't move at all while pumping the lever so that the sticky piston extends? Then push it back in again & repeat as necessary.

    You may have done this, or not. Tough for me to recall.

    If that doesn't work then you're in over my head & I'll agree that you should discuss it with Lonnie and/or Jimi and/or Jude.

    Let me know how it goes.
    Life....the original terminal illness

  5. #5
    mtbr member
    Reputation:
    Join Date
    Mar 2004
    Posts
    47
    Hey, where did the figure of 0.5mm clearance per pad originate from? I thought it would be typically more like 0.3mm per side.

    Just curious. Is there an official spec (within tolerances/out of tolerances)?

  6. #6
    Bodhisattva
    Reputation: The Squeaky Wheel's Avatar
    Join Date
    Dec 2003
    Posts
    9,515
    Got me there Dave.
    I see very little daylight between my pads and I've never bothered to measure the gap, but they run smoothly. I don't worry about it.
    Life....the original terminal illness

  7. #7
    banned
    Reputation:
    Join Date
    Jan 2004
    Posts
    1,088

    I have not only done what you said, I have done it while...

    Quote Originally Posted by The Squeaky Wheel
    I dunno, but rotors warp. usually from heat & use. Really, it's no biggie.

    Have you tried removing the pads and holding the non-sticky piston flush against the caliper body so that it doesn't move at all while pumping the lever so that the sticky piston extends? Then push it back in again & repeat as necessary.

    You may have done this, or not. Tough for me to recall.

    If that doesn't work then you're in over my head & I'll agree that you should discuss it with Lonnie and/or Jimi and/or Jude.

    Let me know how it goes.
    ...using a cone wrench held flat aginst the dominant piston, and my grip rubber spring wedged between it and the sticky piston, to get maximum protraction/retraction with each lever pull.

    I just called Magura, and got a hold of what must be their worst f*cking employee they have, named Jeff (sp). He wouldn't let me finish anything I had to say, and rattled on and on about how the brakes were not set up properly, claiming they should work fine out of the box if set up right. He didn't even give me a chance to explain that the original rear, set up by HH, did the same thing.

    He insisted I should take it to a shop. He also said they never test their brakes before sending them out, even though I told him Lonnie promised he would. He claimed that there's no need for them to test their product, that it works fine if set up properly. He said as well that they never recommend lubing the piston wall after protracting it to free up a sticky piston.

    I don't know what the h*ll his job is at Magura, but if he's the only one there to answer the phone for the first hour each morning as he seemed to imply, there's something definately wrong with their customer service.

    Can you explain to me all the inconsistencies between what he's saying and the Cult/Magura owners advice? According to him, they should require no break in, and he sounded to be saying they don't improve with time, but rather need to be set up right.

    How the f*ck can you "set them up right" with one f*cking piston sticking badly, and the other so dominant it pushes the rotor to one side when you brake. Not to mention pad retraction that is way below the acceptable amount.

    If they're going to try and tell me there aren't any inconsistencies in their product, when the front works fine, and two rears now have had the same ugly problems, they're out of their f*cking minds!

    Do I sound like a happy camper Cult wannabe at this point Squeak, I don't think so.

  8. #8
    A wheelist
    Reputation: Mike T.'s Avatar
    Join Date
    Dec 2003
    Posts
    5,540
    [QUOTE=GnarlygigI just called Magura, and got a hold of what must be their worst f*cking employee they have, named Jeff. I don't know what the h*ll his job is at Magura, but if he's the only one there to answer the phone for the first hour each morning as he seemed to imply, there's something definately wrong with their customer service.[/QUOTE]


    Employee? As far as I know Jeff Enlow's the top fella (manager?) at Magura USA. I've only had contact with him once - he phoned me when he took over as bossman to say hi and thanks to The Cult. I was told (at that time or maybe later, and maybe by someone else, I dunno) that Jimi was our contact person (now it's Lonnie too) and I've had no need to want to change that. Those two guys are 100%. Their dealings with issues are great but probably guided by company policy.

    Mike T. (mcm # 717, ONGO, msps #002)
    Mike The Bike's home wheelbuilding info - dedicated to providing Newby wheelbuilder information and motivation.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Mar 2004
    Posts
    47
    Quote Originally Posted by Gnarlygig

    Are you guys trying to make me sound like an idiot here, or do I need to steer you to the Marta review board and point out all the bad experiences written about even recently?
    Speaking for myself of course, I certainly am not trying to make anyone sound any way.

    I have a set of 04 Louise FR's myself. The front is working pretty well now, the back needs some tinkering. I've been following your posts figuring I might learn something.

    There's a pretty good closeup shot of a properly aligned caliper in the instruction manual for the Magura facing tool. Since the disk is 2mm wide, I measured the gap between the disk and the pads to be around .3mm based on that, and what my setup looks like. Of course that is anectdotal evidence, at best. I thought you might have a more reliable source, sounds like you do.

    Edit: And it looks like I chose about the worst time to ask a question, now that I've caught the middle of the discussion.
    Last edited by dave_f; 06-25-2004 at 06:59 AM. Reason: Missed part of it

  10. #10
    A wheelist
    Reputation: Mike T.'s Avatar
    Join Date
    Dec 2003
    Posts
    5,540

    Your comments offend me.

    Quote Originally Posted by Gnarlygigdo
    ..........do I need to steer you to the Marta review board and point out all the bad experiences written about even recently?
    I'm guessing not all the ones with bad things to say are even posted, considering who the new reviews board administrator is.

    I don't read every post around here but I'm glad I clicked this one. You really know how to win friends and influence people with the above comments if, as it appears, they're aimed at me. I hear your frustrations with your brakes but please don't channel your problems into questioning MY integrity.

    Yes I'm the keeper of the Magura Cult and yes I'm the moderator (not administrator; gregg is) of the Review site and hear me now - I have NEVER and NEVER WILL let my personal opinion affect my job on the Review site. I have a set of guidelines, provided by mtbr, to limit my powers of moderation and to provide guidance. Reviews get removed by me for many reasons (all within the guidelines of what constitutes an acceptable review) and NONE of those guidelines allow me to use favoritism.

    Heck I've probably removed more good reviews of most bikes and parts (including Magura brakes) than I have bad reviews. As long as a review is helpful and objective (bad or good) then it stays. If any product gets slammed or praised without backup reasoning to justify the review or the review contains no helpful information then it's gone.

    My work for both Magura and mtbr is volunteer and unconditional.

    My daily work (forty five minutes so far today and I'm not finished yet) for mtbr is scrutinized by gregg the site manager.

    I would appreciate a retraction of your statements and an apology.

    Mike T. (mcm # 717 & mtbr Review section moderator)
    Last edited by Mike T.; 06-25-2004 at 07:08 AM.
    Mike The Bike's home wheelbuilding info - dedicated to providing Newby wheelbuilder information and motivation.

  11. #11
    (aka SS_MB-7)
    Reputation: 1speed_Mike's Avatar
    Join Date
    Jan 2004
    Posts
    924
    Quote Originally Posted by Gnarlygig
    ...but I'm not even getting half of your idea of good clearance.

    .5 MM is not just something I came up with on my own as a whim, it's the result of lots of gleaning from wrenches that work on them, shops that sell them, and people right here on mtbr that own and maintain them.

    I'll further add that it's about the amount I'm getting in the front, which is way more than the rear.

    Are you guys trying to make me sound like an idiot here, or do I need to steer you to the Marta review board and point out all the bad experiences written about even recently?

    I'm guessing not all the ones with bad things to say are even posted, considering who the new reviews board administrator is.

    My gut told me to go with the Hopes, after good experiences testing them, and I probably should have. Live and learn, anybody want to trade some Minis for Martas? I have a bleed kit and extra set of pads as well. No swag though, I'm certainly NOT a convert.
    Gnarly,

    I can certainly understand your frustrations, but be careful with your choice of words. No one is trying to make you "sound like an idiot"....we are all here for the same reason: to help you.

    I've known Mike T. personally for many, many years. In fact, both of us were on these boards before 95% of those here. And, while he is a review board and the Cult admin, this is no way impacts his fairness and ethics. As guys go, Mike T. is top-notch and he has never given me a reason to question his integrity.

    Now, back to brakes. I've ridden several Hopes (C2 Pros, Minis and Mono Minis). Yes, the Hopes are nice, beautifully CNC'd, powerful with reasonable modulation. But, they just don't have the *feel* of the Magura Martas or Formula B4 SLs (or SL+). Plus, they squeal. I wouldn't say the Hopes are any better than the Maguras or Formulas for installation, set-up and durability though. Of course, your results may vary.
    Ride Hard,
    Mike B. (MCM# 7.77)
    http://www.one-speed.com

  12. #12
    A wheelist
    Reputation: Mike T.'s Avatar
    Join Date
    Dec 2003
    Posts
    5,540
    Quote Originally Posted by Gnarlygig
    ...Are you guys trying to make me sound like an idiot here, or do I need to steer you to the Marta review board and point out all the bad experiences written about even recently?
    I'm guessing not all the ones with bad things to say are even posted, considering who the new reviews board administrator is.

    I believe that if you give people enough rope they will hang themselves eventually. You're not turning out to be an exception to this. I had the great fortune, while I was moderating the reviews just now, to run into your Marta Review . Here are some of my moderating guidelines which are posted even for you to see. I'll let you decide why your review will be deleted before 0700hrs tomorrow -

    __________________________________________________ __

    Top 10 Reasons Reviews are Removed

    All you wrote was "it sucks, don't buy it"
    You used profanity
    You insulted or attacked other reviewers
    You don't actually own the product
    You posted your review multiple times
    You tried to sell something (go to the Marketplace)
    You ranted about poor customer service rather than reviewing
    the product. Comments about customer service may be included
    in your review, but it should not be your whole review.
    You didn't write enough, especially if you are reviewing a
    complete bike. 50 words is the minimum for a complete
    bike review.
    You didn't substantiate your review (positive or negative)
    You didn't leave a valid email address
    We do NOT remove negative reviews solely because they are negative. If
    you have something negative to say, you MUST substantiate it with as
    much detail as possible. If a manufacturer genuinely wants to contact
    you to rectify the situation, but cannot reach you because you did not
    leave a VALID email address, then your review may be removed.
    Conversely, if you rave about how great a product is but you do not
    say why or do not include enough detail, your review may be removed.
    We do remove good reviews as well as bad ones if they are not subs-
    tantiated in your review.
    Bottom Line: Your Review Must Be Useful and Informative!
    __________________________________________________ ____

    And by the way - since last August when I started this job, I've deleted ONE Marta review and it didn't come close to meeting the required word count or objectivity. I just checked.

    I'm all done dealing with you. I'll let the others decide for themselves.
    Mike The Bike's home wheelbuilding info - dedicated to providing Newby wheelbuilder information and motivation.

  13. #13
    Bodhisattva
    Reputation: The Squeaky Wheel's Avatar
    Join Date
    Dec 2003
    Posts
    9,515
    Quote Originally Posted by Gnarlygig

    Do I sound like a happy camper Cult wannabe at this point Squeak, I don't think so.
    No, you don't. You sound as if you have serious anger management issues.

    It's unfortunate that you've had so many problems. Truly.

    All the Cult members have tried to do is assist you. It's free advice. Take it for what's it worth.

    Mike's a big boy & I won't delve into your comments too much, but me thinks you need to reconsider your statement. I've been on this board for over 5 years and nobody, I MEAN NOBODY, has been more helpful and more of a contributer of good will & advice than Mike. Critisizing him on this board is analagous to slamming the Pope in Rome. Nobody is going to believe you and it makes you look like a raving loonie.

    I'm going to have to sign off on helping you now but I wish you the best of luck.
    Life....the original terminal illness

  14. #14
    Do It Yourself
    Reputation: Homebrew's Avatar
    Join Date
    Jan 2004
    Posts
    5,722

    My question is...

    How do the brakes ride? Would you know there was a problem if you were like most people and just took the bike out of the box and hit the trail? My Martas weren't perfect either. However, they rode great and never gave me any trouble. This dominant piston seems to be dominating your thoughts.

    Good luck.
    Long Live Long Rides

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •