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  1. #1
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    Avid Mech is driving me crazy!! Please Help!

    Someone may remember the weird problem I had with my front wheel locking up a month or so ago. The bike shop decided they installed the cable too short and re-did it for me. Brakes worked fine for a few rides, although they never completely stopped singing while I'm peddling.

    Saturday, they were singing/squeeling like mad as I peddled up hill for about 4 miles, getting dropped by EVERYONE. I finally stopped to check the brakes and sure enough, the front wheel is locked up where I can barely turn it with my hand. I pulled the brake lever (XTR) until it "snapped", just like last time, and the wheel spun free. Also, I noticed my computer wires were pulled out. Apparently, this time, instead of attaching my brake cable to the fork crown which was helping it f-up last time, now they had attached my computer cable tightly to the brake housing.

    So, after that, the wheel spun OK all day, but the brakes continue to make an almost constant noise under any peddling, significant force not required. No noise at all upon braking and they brake like a charm.

    What in the hell do I do? My husband will not help, says it's not dragging, don't worry about it. I think it IS dragging, why else the noise? The bike shop that installed it has now looked at it twice. Is there something I should tell them to look for? Should I try another shop? I would appreciate any help.

  2. #2
    aka Willy Vanilly
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    Here's my .02: Try sighting down the rotor while you give the front wheel a spin. See if the rotor wobbles at all while it passes through the caliper. If it does, you might try straigtening the caliper (I use a paper towel (to keep hand oil off the rotor) and my fingers to either push or pull it just a bit until it is straight).

    Try re-wrapping your computer cable loosely around the front brake housing.

    See if the cable ends (at the brake lever and at the caliper (under the rubber seal) are seating correctly. Or if they kind of pop out or something when you hit the brakes once and let go. Perhaps they are not returning to their original positions (?) If so, try putting some constant tension in the cable by unclamping the pinch bolt at the caliper (that holds the cable down) and pushing it up by hand a little bit (you'll feel the spring "coiling") and the clamping. This will make sure the cable is always being pulled by the caliper. Might have to make brake pad adjustments to compensate.

    Try and figure out which of the pads is rubbing. Start with that pad and move it one click counterclockwise by turning the reb knob on the rotor (there is one against the spokes and one on the outside). Squeeze the brakes and test by riding or spinning the wheel. If that works, you're done. Keep in mind though that this could potentially change the feel at the lever. To compensate, you could move the opposing pad in/clockwise the same number of clicks that you moved the other one out/counterclockwise.

    Good luck. Let us know if you figure it out.
    Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.
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  3. #3
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    avid mech

    i agree with will8250, i have set up a lot of brakes in the past (used to work at a shop) and the avid's were by far the easiest to set up and adjust. i had the same problem with mine at first: after the cables were stretched, i just had to make sure the caliper was centered (using the small shims) and then i did what will8250 mentioned above with the dial's on either side of the caliper

    no problems since, they are great--let us know how it goes!

  4. #4
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    It's not normal for them to make noise that way...

    and as noted before, Avids really are easy to set up relative to other brakes. Something is wrong, whether hubby says so or not.

    1. Keep the computer wire off of your brake cable (obvious, I know). Route it down the other side of the fork.
    2. Get rid of the XTR levers and get Avid levers (which your brakes were designed for and, yes, they are different). I use Avid brakes on both my bikes, one with Avid levers, one with XTR levers, and the Avid set up is way, way, way, way better (though the XTRs do work).
    3. Have the shop readjust your brakes, again, having told them what you just told us so they check the rotors for trueness as well. If they still can't get it right you need a new shop. The only time you should hear those brakes is when you are using them, and even then they shouldn't squeal unless they are wet.

    My .02,

    Michael


    Quote Originally Posted by litespeedchick
    Someone may remember the weird problem I had with my front wheel locking up a month or so ago. The bike shop decided they installed the cable too short and re-did it for me. Brakes worked fine for a few rides, although they never completely stopped singing while I'm peddling.

    Saturday, they were singing/squeeling like mad as I peddled up hill for about 4 miles, getting dropped by EVERYONE. I finally stopped to check the brakes and sure enough, the front wheel is locked up where I can barely turn it with my hand. I pulled the brake lever (XTR) until it "snapped", just like last time, and the wheel spun free. Also, I noticed my computer wires were pulled out. Apparently, this time, instead of attaching my brake cable to the fork crown which was helping it f-up last time, now they had attached my computer cable tightly to the brake housing.

    So, after that, the wheel spun OK all day, but the brakes continue to make an almost constant noise under any peddling, significant force not required. No noise at all upon braking and they brake like a charm.

    What in the hell do I do? My husband will not help, says it's not dragging, don't worry about it. I think it IS dragging, why else the noise? The bike shop that installed it has now looked at it twice. Is there something I should tell them to look for? Should I try another shop? I would appreciate any help.
    I'll be along... eventually.

  5. #5
    aka Willy Vanilly
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    Not to derail the thread or anything but I'm curious as to what you like more about the Avid levers over the XTR. Personally, I'm much more of a fan of the shape of the Shimano levers than the Avid (which I felt were too flat across the front). Do you notice a real performance difference?
    Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.
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  6. #6
    Te mortuo heres tibi sim?
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    one option

    yep, what they said.

    and try another shop. that one sounds like they really don't know how to set avid's up very well. they are dead simple, really.

    what fork? here's what i've got going, on two marzocchi forks. works great. no binding up. the one in front has the comp cord wound around, too. computer is setup on the disc side of the fork. keeps everything on one side, nice and sano/uncluttered looking.







    if you don't have a zocchi with that convenient hole in the crown, you can use one of the stick on cable things on the back of the fork leg. one of mine has that. the one in the pics has a couple of glueless patches holding it to the back of the fork leg, with a part of the cable that doesn't move. zipties work well, too, and are cheaper. i justlike the clean look of this way.
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  7. #7
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    avid mech

    I should have mentioned this in my earlier post ---- I am using avid speed dial 7 levers. I can keep the kind of tension on the pull the same if i have to adjust the caliper by adjusting the lever. In my experience, the avid mech's are easier to fine tune with speed dial levers than with xtr (and barrell adjusters) but i have never used xtr personally, so take this with a grain of salt!


    Plus -- I like the fell of the avid speed dial levers better, but that's just me!

  8. #8
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    You can adjust the leverage with Avids...

    ...not just the cable throw. So, if you like the brakes to modulate better you use less leverage. If you want more power you use more leverage. You adjust that independantly of the cable throw, which you can also adjust with the levers (though with Avids you would typically do that at the caliper.

    The XTRs can only adjust cable throw.

    Quote Originally Posted by will8250
    Not to derail the thread or anything but I'm curious as to what you like more about the Avid levers over the XTR. Personally, I'm much more of a fan of the shape of the Shimano levers than the Avid (which I felt were too flat across the front). Do you notice a real performance difference?
    I'll be along... eventually.

  9. #9
    aka Willy Vanilly
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    actually, I believe there is a leverage adjustment on XTR levers. not as cool as the speed dial, but it is there.
    Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.
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  10. #10
    aka Willy Vanilly
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    Pardon... 2002 XTR levers. No clue about the new integrated stuff
    Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.
    E. F. Schumacher

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  11. #11
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    Quote Originally Posted by mtbykr
    i agree with will8250, i have set up a lot of brakes in the past (used to work at a shop) and the avid's were by far the easiest to set up and adjust. i had the same problem with mine at first: after the cables were stretched, i just had to make sure the caliper was centered (using the small shims) and then i did what will8250 mentioned above with the dial's on either side of the caliper

    no problems since, they are great--let us know how it goes!
    Why did you need shims to center the caliper? Not usual for Avids.
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  12. #12
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    Quote Originally Posted by shiggy©®™
    Why did you need shims to center the caliper? Not usual for Avids.
    Shig, remember I needed shims for the rear Avid on my Komodo, with XT hubs. I still need them with the SRAM 9.0sl hub, so I can't blame it on the hub. First gen calipers, though, don't know about the new ones.

  13. #13
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    I use older XT brake levers. The front has one shim taken out of the lever to increase modulation & ultimate power (counter-intuitive with the power bit, but with both shims in I don't get the best power). I left both shims in the rear-lever.

  14. #14
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    shim adjustment

    Woodman lefty hub on the front and crossmax on the rear. they were both a little different but the main adjustment was to center the caliper vertically for correct contact. a little adjustment was needed to center horizontaly on both so the rotor would not rub when it came around (it was a little warped) --of course a little was just me wanting it to be as perfect as possible!

    hope this helped

  15. #15
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    I know this is a little late and you may have already solved your problem but I'd be a lot more concerned about the brakes locking up than the slight singing or rub. All the advice on adjusting the brake I read is very good. The locking up part sounds as if the cable end inside the brake lever is sliding out of position inside the brake lever bracket and not seating back properly. This could happen after you brake and release the lever and the lever moves back faster than the cable itself. Not enough tension on the caliper or sticky cables would cause this to happen. It would explain the cable "snapping back into position" and then being okay. Just something to check before it locks up on you again.
    "Never waste a downhill"

  16. #16
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    Thanks.

    I took the bike BACK to the bike shop that installed it. They "adjusted" it and gave it back. It seemed slightly better for about 1/2 the ride and then begin to shreek again. So this week I took it up to Asheville, about 45 min from here, where sometimes the mechanics are a little better. They replaced the cables again(don't know why) and "adjusted" it some more. I haven't ridden it since, but I don't have a good feeling about it. My husband picked it up and did not get any kind of details on what might have been wrong. I'll probably be posting back here next week. *&A$^*&#*$^*#

  17. #17
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    Just something the other guys didn't mention, and it's such an old topic, I forgot it myself.

    Did you ask the shop if they "pre-stretched" the cables, usually by clamping the pads as tight as they can go, then hauling back on the brake levers?

    If they DID do this, you have two broken brakes, and your shop needs to replace them. Doing the pre-stretch thing on Avid mechs will break the retaining clip in the pistons, and cause them to not retract properly.....it's an old Avid tech bulletin, but *some* shops may not have gotten it, or disregarded it. This happened alot when the brakes first came out, and I lost track of the shops that said the Avid bulletin was bunk, and they'd continue to
    "stretch" the cables, and no harm would come to the brakes. Avid's replacement rate begs to differ.......alot of shops caused alot of damage.

    Ask the original shop if they did this.....if they did, then I have the tech bulletin, in PDF format, that shows you how to replace the lockring. Perhaps give it to your shop, along with a good serving of boot in the rump?

  18. #18
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    Just as kind of a gee whiz...I've got a set of Avid mechs on my bike, everytime they start to squeal it's usually because my rotors are starting to glaze. Straight Dawn dishsoap, hot water, and a scotchbrite quiet them right down, make sure that you scrub both sides of the rotor. You don't want to scratch the heck out of the rotor, just break the glaze and clean them up. Good luck.
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  19. #19
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    Thanks. I'll ask them. But...at this moment I'm holding my breath that the Asheville bike shop did fix the problem. I rode about 20 miles Saturday with no squeeling and , since no one had to come looking for me on the climbs, no drag I assume. I think I'll call that bike shop and ask if they found anything specific wrong just for future reference. Cross your fingers!!

    And now, please look at my post re: my husband's new Avids.

  20. #20
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    Quote Originally Posted by litespeedchick
    Thanks. I'll ask them. But...at this moment I'm holding my breath that the Asheville bike shop did fix the problem. I rode about 20 miles Saturday with no squeeling and , since no one had to come looking for me on the climbs, no drag I assume. I think I'll call that bike shop and ask if they found anything specific wrong just for future reference. Cross your fingers!!

    And now, please look at my post re: my husband's new Avids.
    I hope you aren't paying these "mechanics" good money to adjust your brakes. If you follow the directions in your owners manual you should be able to align the calipers in at *most* a half-hour. It's almost stupid proof.
    I would guess that at that last shop you stumbled upon someone who can both read and follow directions.

    If your brakes are dragging and squealing a quick fix is to just dial back the calipers a couple clicks.

  21. #21
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    Why does this work?

    Quote Originally Posted by switch
    If your brakes are dragging and squealing a quick fix is to just dial back the calipers a couple clicks.
    Okay, I have a new bike that has Avid Mechanicals on it. I have Avids on my other bike and they are simple to setup, etc. Had some squealing on the brakes when I first set them up but it disappeared within 10 minutes of riding.

    Now, on my new bike, the Avids squeal like a stuck pig. They are NOT dragging.

    Anyway, I tried the alcohol thing; the dawn/scotch brite thing; roughing up the pads; etc. Nothing worked.

    Then tried dialing back the calipers a couple of clicks (as switch suggested) and it solved the problem.

    Can anybody explain WHY this worked?

  22. #22
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    squealing rotors

    Are your rotors "singing" when you get moving faster? If they aren't dragging, I'm confused how they could be squealing if nothing is touching.

    I have a 185mm rotor up front, and found that when I hit a certain speed on harder surfaces (hard dirt or pavement), my front rotor will sing to me. I can fix it by opening up my calipers a bit, but then I end up having to move my brake lever further than I like to when I brake. So I leave them a bit tighter and let them sing.

    I think the reason they sing is that the vibration of the tire on the hard surface and the bigger (and therefore more flexible) rotor cause it to vibrate and touch the pads a little.

    -John

  23. #23
    Jm.
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    Your brake caliper is not completely/perfectly aligned with the rotor.

    There are a few reasons why this may be, one is that the disc brake tabs on your frame are not perfectly aligned. This is totally possible and there are tools to face them to make them "correct". Another reason is that when you loosen the bolts, squeeze the brake lever, and then tighten the bolts (this uses the Caliper Positioning System), you may be torqing the caliper while you are tightening the screws, this may throw the position of the caliper off a bit. This is hard to avoid, but usually the effects are not drastic and it may not throw the caliper "off" at all. On the other hand, a slightly un-true rotor will exaggerate the problem. The slightly-out of true rotor is of course another possibility, as is the fact that when you have ridden extensively with a rubbing brake, the pads eventually get worn down "un-evenly" and when you set the brake up properly, it may squeal like crazy because the pads now have a different shape, in other words they may be "tilted" to one side. Fork flex could also be causing this as well. A disc brake on a SID may howl or screetch a lot more than one that is mounted on a solid fork, like a fox or marzocchi.

    A lot of the above problems may not be apparent, and are of the sort where they may not appear to be a problem when you re-adjust the brakes (or the bike shop does it), but a little while after with a few miles on them, the same things keep happening.
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  24. #24
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    Do I have a warped rotor?

    The avid brakes that I've been using for the last three months are great, but in the last couple of weeks I've had an annoying shinnkky-shinnkky-shinnkky noise coming form my rear brake at certain speeds going downhill (sometimes uphill too) on smoother trails and the road. It almost sounds like the rotors are loose, though I've checked and they seem pretty secure.

    Numerous adjustments on the trail, at home and at the shop have been unsuccessful. The mechanics at my LBS tinkered with them for an hour and, while the noise disappeared when the bike was on the rack or in the stand, the dreaded shinnkky shinnkk came back on my next glide down the road.

    Could this be a bent or warped rotor? The bike's taken a few knocks so this could be the case. I heard having the wheel and rotor trued will work, but is it true that it will work only for a short time?

    For reference the bike is a Turner 5 Spot with XT hubs, Maxis3.1 tubeless rims and salsa skewers, and I'm using the avid levers too.

    Cheers, Duncan

  25. #25
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    Quote Originally Posted by Duncan
    The avid brakes that I've been using for the last three months are great, but in the last couple of weeks I've had an annoying shinnkky-shinnkky-shinnkky noise coming form my rear brake at certain speeds going downhill (sometimes uphill too) on smoother trails and the road. It almost sounds like the rotors are loose, though I've checked and they seem pretty secure.
    Cheers, Duncan
    Duncan,

    This sounds just like the issue that I have with my brakes "singing" on hard surfaces, that I mentioned above. That's why it didn't do it when the bike was on the rack. I think that the rotors just aren't all that stiff laterally, and the vibration from the tire causes the rotor to vibrate enough to tough the pads.

    Probably, the only thing you can do is to adjust the calipers to move the pads away from the rotor a bit.

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