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  1. #1
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    Campy Ergo body binding against brake levers

    I rebuilt my Record shifters, and when I reinstalled the pivot pins that fix the brake levers in the body, there apparently was enough friction between the pin and the polymer body that driving the pin through the hole also pushed the sides of the body flanking the lever a touch too close together. Now the body apparently fits too snugly against the sides of the brake levers and they bind, preventing the levers' from auto-returning when released. So when I brake, I have to manually push the levers forward a bit to get them to return to the full-forward position. I've tested the brake levers removed from the handlebars and with the cables uninstalled, and I've tested the cable return with the brake levers not attached, and there obviously is some binding between the body and the lever. Throw in cable friction and it's more friction than the brake return spring can overcome.

    Driving something narrow between the lever and body to create a touch of clearance seemed like the natural solution, but the fit is so tight, the only thing I possibly could get between them would be a knife blade. And I don't want to try that because I figure I'm almost certain to end up cutting into either the CF lever or the polymer body in the process. Not to mention the body is far more substantial than the lever, so all that would happen probably would be making the sides of the lever flex inwards, which I don't see helping my cause any.

    Long story short, I figure to disassemble and reassemble them to try to fix that. Anybody have any suggestions how I can put them back together without reproducing the same "pinching" as I did the last time?

  2. #2
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    The ears aren't flexible enough to move without cracking. I suspect you might have shaved a burr off as you drove the pin through. Try the easy fix of tapping the pin out 1/8" in each direction then recentering it and see if that solves it. Otherwise remove the pin, inspect the levers and the bushings, and fit between the ears to check that the clearance is OK, then resetting the pin.

    Otherwise, it might simply be a question of lack of lube, or cable binding in the housing so the brake can't pull the lever back effectively. Cable friction is enough of an issue with the light springs that brakes use, that some years back DiaCompe added a spring in the lever to help, calling it the BRS (balances response system).
    FB
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  3. #3
    Let your bike be the tool cranky old road's Avatar
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    When I push a chain's pin back in to close a chain I often finish by pushing it in the opposite direction a bit as if I were breaking the chain again. This frees the joint up. I wonder if a similar approach would work with the brake lever pin?

    ED. FBNY knows what he's talking about. I, not so much.
    Never try to teach a pig to sing...

  4. #4
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    The problem turned out to be corrosion or oxidation on the brake lever pivot pins.

    I had to brutalize the pins to get them out. The left-side had white spots on it that obviously were corrosion. The pins aren't magnetic but I wasn't sure initially whether they were alu or Ti.

    The right-side pin was a real booger-bear. I bent a 3/8" punch getting it out. It had even more of the white crud on it than the left-side pin did.

    Unfortunately, I didn't think to take photos before I cleaned them up. I chucked them in an electric hand drill and polished them with 00 steel wool followed by some Flitz polishing paste. Which got rid of the corrosion but took some material with it.



    I discovered it's really difficult to get a good macro photo of something this shiny, buy you still can tell there is a lot of pitting. While they still were in the drill, I used a flat file to turn down the mushrooming I had caused beating on them with a punch, and radiused the shoulder just a touch.

    I know Ti will oxidize too, but I have to figure this had to have been caused by perspiration (who knew I sweated so much?). Doubly troubling because I only rebuilt them last spring. I lightly polished the pins then with 00 steel wool, so there shouldn't have been any appreciable corrosion left. Which made me curious what they were made of, so I jury-rigged a Jolly balance from a balance beam scale accurate to the 1/10th part of a grain and measured their specific gravity. It came out to 2.79, which puts it at the upper end for aluminum, but far enough below the SG of Ti that I knew I couldn't have made an error big enough to span the difference. Definitely aluminum.

    After the pivot pins were cleaned and polished, the brake lever swings freely under nothing more than its own weight, which is a far cry from the way it was before. So the corrosion definitely was the cause of the problem. I reassembled them with a dollop of Moly-based antiseize on them, and now they work as well as when they were new.

    NOTE TO SELF:
    Remove and re-grease brake pivot pins quarterly.
    Last edited by NattyBumpo; 06-29-14 at 02:13 PM.

  5. #5
    Andrew R Stewart Andrew R Stewart's Avatar
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    Good job on figuring out the problem. It is amazing how some of us are real acid droppers and others with more sweat volume don't have the corrosiveness that the others do. If the lever pivot pins were this bad i wonder about the thumb release levers' pivots and springs. I've had to replace them a couple of times over the years. Andy.

  6. #6
    bike whisperer Kimmo's Avatar
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    Sometimes Shimano or Campy get a bit carried away with the lightening on DA and Record... ally pivot pins for the brakes is verging on silly.

    And if you're gonna use ally, it should be anodised. Bit bloody slack for Campy...

    Quote Originally Posted by Andrew R Stewart View Post
    It is amazing how some of us are real acid droppers
    I'd put myself in this category, but I'm not sure how corrosive my sweat is... check out the pic on my profile page

  7. #7
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    Quote Originally Posted by Andrew R Stewart View Post
    Good job on figuring out the problem. It is amazing how some of us are real acid droppers and others with more sweat volume don't have the corrosiveness that the others do. If the lever pivot pins were this bad i wonder about the thumb release levers' pivots and springs. I've had to replace them a couple of times over the years. Andy.
    Since you mention it, one of the things that forced this rebuild was that the right side thumb pivot was getting very, very sketchy, so I already had a replacement in hand I'd ordered from Branford Bike weeks ago. But I am not handy with small bits and I have to be in a very Zen-state before I'll tackle something this intricate/frustrating [pick one], so I'd been riding my beater for a few weeks. When I finally got around to disassembling that right side shifter, the thumb pivot was utterly fixed and rigid.

    What perplexes me about this is that this gruppo is nine seasons old and has never shown this tendency to rust. It's been stored in the same place that entire time, and I did another rebuild just spring of last year (Bradford's intermediate mileage rebuild kit). Anything that wasn't replaced was scrubbed with PB Blaster and 00 steel wool, including the brake pivots, so I know everything was clean and corrosion free just a year ago. It must be that my sweat has turned nukular as I've gotten older.

  8. #8
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    Quote Originally Posted by NattyBumpo View Post

    What perplexes me about this is that this gruppo is nine seasons old and has never shown this tendency to rust. It's been stored in the same place that entire time, and I did another rebuild just spring of last year (Bradford's intermediate mileage rebuild kit). Anything that wasn't replaced was scrubbed with PB Blaster and 00 steel wool, including the brake pivots, so I know everything was clean and corrosion free just a year ago. It must be that my sweat has turned nukular as I've gotten older.
    The pins are anodized and usually fairly corrosion resistant. If you cleaned them abrasively you would have stripped the anodization, leaving them more prone to salt damage.

    Keep the pivots oiled, especially the riveted pivot on the thumb lever and they'll stay fine forever. All it takes is one drop of decent oil once a season or so.
    FB
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    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  9. #9
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    They didn't make it a full quarter. Yesterday they started sticking again. Amazing how fast the corrosion returned. I put a light coat of moly-copper antiseize on them when I reinstalled them, and this is all the longer it lasted. This time I'll try lithium grease. The inner side of the left side brake pivot had to much salt accumulated on it, it looked like the ash hanging off a fine cigar. Must be the Cytomax.

    NOTE TO SELF:
    Remove and re-grease brake pivot pins ...monthly.

  10. #10
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    Quote Originally Posted by NattyBumpo View Post
    They didn't make it a full quarter. Yesterday they started sticking again. Amazing how fast the corrosion returned. I put a light coat of moly-copper antiseize on them when I reinstalled them, and this is all the longer it lasted. This time I'll try lithium grease. The inner side of the left side brake pivot had to much salt accumulated on it, it looked like the ash hanging off a fine cigar. Must be the Cytomax.

    NOTE TO SELF:
    Remove and re-grease brake pivot pins ...monthly.
    You obviously sweat and salt is death on aluminum. Consider painting them, which will offer much more protection.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  11. #11
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    Quote Originally Posted by FBinNY View Post
    You obviously sweat and salt is death on aluminum. Consider painting them, which will offer much more protection.
    I've always considered myself a very light sweat-er, but I notice a great deal more salt caking on my clothes when I'm on the Cytomax. So I wasn't being at all facetious when I suggested it was playing a role in this problem.

    And it has been quite hot and humid here for the past month. At the end of most of my rides, my clothes are wringing wet.

    I'll try the painting, thanks for the tip. It makes sense because any kind of lube I use will tend to be squeegeed off by the tight friction fit of the pin against the shifter body.

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