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  1. #1
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    I hate the new XT 2012 brakes

    This is how much:

    !@#$!@#$!@#$!@#$!@#$!@#$!@#$!@#$@@X$@@!#@#$!@#$@!# $!!@#$@!#$@#$@!#$!@##!@@#!$!@#$@#!$@#$@#!$$@#!!@!! !!!!!!!!

    For the last four hours, I've been trying to install the front brake so that the pads don't rub against the rotor. I've loosened the mounting bolts at least 50 times, and following the instructions I depress the brake lever and then tighten the mounting bolts. But the rotor always rubs.

    I've tried tightening the clamping bolts after pushing the brake cable forward, backward, and to the side. I've also tried it with the brake housing clamped to the Fox cable guide on the left fork leg and unclamped. I've tried tightening the bolts with the handlebars turned to either side as well as pointing straight ahead. Nothing works!

    There are 3 washers, 2 sides to the adapters in addition to the post mounts, and as far as I can tell there is no may the tolerances of all those surfaces is going to allow you to line up a rotor that has at most 1mm of clearance to the brake pads on each side of the rotor. Depressing the brake lever while tightening the mounting bolts does absolutely nothing to prevent the brakes from rubbing against the rotor.

    My brakes came completely assembled, but I resorted to removing the brake pads in order to try pushing the pistons in. They didn't budge--but it's not like I could can get any leverage on them. They are white(is that the piston?) and both stick out about 1mm.

    Oh yeah, I had to buy a Torx wrench to install the RT75 rotors. What idiots would ever use torx bolts for any application? The person who invented the torx wrench?? And the instructions for the rotors say I am supposed to bend the tightening plate over the bolts? Impossible!

    I will never buy another Shimano product again. I've never seen a system so badly designed. How is it possible that there isn't an adjustment screw for each brake pad?

    !#@$!@#$!@#$!@#$!@#$!@#$!@#$!#@$!@#$!@#$ you Shimano!

    not happy, not riding
    Last edited by happyriding; 09-30-2011 at 02:34 PM.

  2. #2
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    Have you looked at the rotor. Could it be warped. Is it new. Just a thought.


    Sent from my iPhone using Tapatalk

  3. #3
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    Brand new rotor, never used. Spins straight and true, not warped.

  4. #4
    Weird huh?
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    Another possibility: Pull off the front wheel and put it back on paying careful attention to making sure it's precisely centered. If even slightly off by a half a millimeter in one of the dropouts on your fork, it'll rub.

    Good luck!
    ...You'll find me chugging a gallon of Pliny sooner than going hipstertard ~ Menso

  5. #5
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    Thanks. I thought of that too. When I removed the brake pads, I had to remove the front wheel, so I thought remounting the front wheel might help. I have a 20mm through axle fork, and the tolerances of the through axle are pretty tight--in fact it is a pain to get it to slide through the second fork leg.

  6. #6
    Moosehead
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    Have you ridden the bike and/or bedded in the pads? This usually does it, especially for the XT's which are typically easier setup than most hydraulics.

    Other possibility is too much fluid in the system, a bit less may cure the problem but would try bedding them in first.

    Toss out the lock tabs that are to be bent over the torx bolts, most wrenches do the same.

  7. #7
    GUIDANCE COUNSELOR
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    Find a business card. Cut it in half. With the caliper bolts loose, slide each half between each pad and the rotor. Depress brake lever while tightening caliper bolts.
    NOAH SEARS
    MRP
    TECH QUESTIONS HERE: INFO@MRPBIKE.COM

  8. #8
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    Quote Originally Posted by happyriding View Post
    For the last four hours, I've been trying to install the front brake so that the pads don't rub against the rotor. I've loosened the mounting bolts at least 50 times, and following the instructions I depress the brake lever and then tighten the mounting bolts. But the rotor always rubs.
    Holding the brake lever on and then tightening the bolts doesn't really work that well for aligning disc brakes. It's better to align the pads by eye. Assuming that your brake rotor is completely true (difficult to tell just by looking at them) then the easiest way to align brake pads is usually outdoors in direct sunlight. The sunlight shows up the small gap between the pads and rotor more clearly than doing it indoors.

    For the front brake if you turn the bike upside down so that it is resting on the saddle and handlebars then you can look down through the caliper and see the clearance between rotor and pad. Don't pull the brake lever whilst the bike is upside down. Part tightening the caliper bolts and then gently pushing the caliper sideways small amounts allows you to fine tune the alignment of the caliper with the brake rotor. By having the bolts part tightened it allows you to make fine adjustments to the caliper alignment.

    If the rotor is warped then you can true it by carefully bending it straight.

    Disk Brake Rotor Precision Truing

    If it's a new bike build then you might need the suspension fork's post mounts faced also so that they're flat.

  9. #9
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    Quote Originally Posted by happyriding View Post
    Oh yeah, I had to buy a Torx wrench to install the RT75 rotors. What idiots would ever use torx bolts for any application? The person who invented the torx wrench??
    Sorry, but that's standard for all 6-bolt disc brakes. Torx bolts are starting to pop in lots of other places now too (chainring bolts, stems, etc). Every multi-tool in recent years has had a Torx T25 wrench. "Those people" were smart because torx heads do a much better job of resisting stripping out compared to whatever size hex head you could fit on the size bolt head.

  10. #10
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    Quote Originally Posted by WR304 View Post
    Holding the brake lever on and then tightening the bolts doesn't really work that well for aligning disc brakes. It's better to align the pads by eye.
    +1

    I was frustrated and unable to centre my SLX calipers using Shimano's "squeeze the lever" technique. Doing it by eye worked great. The clearance on each pad is extremely tight.

    Also, the pistons in my calipers stick out a tiny bit when they are all the way in. I don't think this is a problem

  11. #11
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    are your fork/frame tabs clean, and faced?

  12. #12
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    Is one pad rubbing or are both pads rubbing? Aligning a caliper is a delicate deal. Never use the "squeeze the lever" method, doesn't work. You should align it visually and tighten it as you watch. It is common for the caliper to "walk" out of postion if you crank the bolt really hard or too fast. Tighten the bolts slowly, very slowly. In some cases, you may even need to put some force against the caliper with one hand as you tighten the bolts to keeping it from "walking".

    If both pads are rubbing, try riding it around the block a few times. If that doesn't fix it, there may be too much fluid in the system.

    Have you considered taking it to your LBS???
    fee-fy-fo-fum...

  13. #13
    mkk
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    Quote Originally Posted by moosehead View Post
    Have you ridden the bike and/or bedded in the pads? This usually does it,
    Maybe it's just the brakes that I've used, but whenever I change the pads I get some rub until I bed them in- especially with brand new rotors. The squeezing the brake lever method of centering the caliper has also always worked for me. They are supposed to be "self-centering." Maybe I've just been lucky with that, though.
    The new XTs are supposed to be pretty hassle free. If it's really that much of a PITA to line them up, I wouldn't be surprised if something was defective. But just try bedding them in properly first (if you haven't already) before you go any more ape-****.
    Also, I understand the frustration and the need to rant, but I've never seen anything other than torx bolts on rotors.

    Best of luck.

  14. #14
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    Quote Originally Posted by happyriding View Post
    My brakes came completely assembled, but I resorted to removing the brake pads in order to try pushing the pistons in. They didn't budge--but it's not like I could can get any leverage on them. They are white(is that the piston?) and both stick out about 1mm.
    This is likely your problem, the pistons are sticking out too far. Rotate the lever assembly so the master cylinder is horizontal and then loosen the bleed screw slightly. Now press the pistons in by inserting the plastic separators that came in the front & rear calipers and wedging a screwdriver between them. You should be able to get the pistons flush with the caliper surface. Don't forget to tighten the bleed screw before moving the lever. I just went through this with new M666 SLX brakes.

  15. #15
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    Thanks for all the responses.

    I ended up adjusting the pads by feel. With the brake mounting bolts loose, I pulled the brake body away from the wheel so that the inside pad hit the rotor. Then I moved the brake body outwards in small increments, tightened the caliper bolts, and spun the wheel to listen for rubbing.

    The Park Tool website also has a couple of suggestions:

    Park Tool Co. » ParkTool Blog » Shimano® Hydraulic Brake Service and Adjustment

    The one that helped me finally get the front brake aligned was to only undo one of the mounting bolts and then pushing on that end of the brake body to move the pad slightly.

    Depressing the brake lever does squat. !@#$@!##@! Shimano for the shite instructions. Thanks mtbr for the real instructions!

    As for facing, my LBS said not to bother with the post mounts on the fork because they said the adjustment was going to be side to side. But they did face the rear brake mounts. The facing on the rear didn't make any difference: squeezing the brake lever, then tightening the bolts led to rubbing. I tried five times, and the brakes rubbed each time. Once again, I removed the brake pads and checked the pistons and they each protruded about 1mm just like in the front. So I ended up adjusting the rear brake by feel too.

    The reason I decided to remove both brake pads was because when I was mounting the levers on the handle bars, I gently squeezed the brakes while checking their position, and then I noticed that the orange insert had fallen out of one of them. I thought maybe the pistons on one of the brakes might be screwed up because of that.

    I have a question, there is a long thin bolt I unscrewed to remove the pads--it had a clip on the end of it. When I unscrewed that bolt it seemed to break free as if was glued in there--but the Park Tool website doesn't mention putting any loctite on there when reinstalling. Does that bolt need loctite?

    Now I'm watching for leaking brake fluid. I've got my fingers crossed.

    Oh yeah, after aligning the rear brake, I realized I needed to route the cable on the inside of the chain stay. Rather than remove the rear brake, I'm going slide everything off the bars and use the brake lever to route the cable. I want no part of adjusting the rear brake again!
    Last edited by happyriding; 09-30-2011 at 10:11 PM.

  16. #16
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    Quote Originally Posted by NoahColorado View Post
    Find a business card. Cut it in half. With the caliper bolts loose, slide each half between each pad and the rotor. Depress brake lever while tightening caliper bolts.
    I can't see how that could possibly do anything. The whole problem is that the mounting bolts can flex the rotor. Adding business cards won't prevent that.
    Last edited by happyriding; 09-30-2011 at 10:25 PM.

  17. #17
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    Quote Originally Posted by moosehead View Post
    Have you ridden the bike and/or bedded in the pads? This usually does it, especially for the XT's which are typically easier setup than most hydraulics.

    Other possibility is too much fluid in the system, a bit less may cure the problem but would try bedding them in first.

    Toss out the lock tabs that are to be bent over the torx bolts, most [mechanics] do the same.
    Thanks. I couldn't get a small screwdriver under the tightening plates to bend them, and after a few seconds of trying, I gave up. I just laughed at what a miserable idea those tightening plates are, and I didn't waste any more time on it. The bolts have some blue stuff on it, which I assume is loctite.

  18. #18
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    Quote Originally Posted by happyriding View Post
    I have a question, there is a long thin bolt I unscrewed to remove the pads--it had a clip on the end of it. When I unscrewed that bolt it seemed to break free as if was glued in there--but the Park Tool website doesn't mention putting any loctite on there when reinstalling. Does that bolt need loctite?
    Glad you've got the alignment sorted out. Hopefully you'll come to enjoy your brakes It is surprising that Shimano continues to publish that method when it can easily not work. They should at least add a "If the pads continue to rub..."

    I've heard that the little clip doesn't matter. Plenty of people lose them without problems. Just make sure the bolt is tight (not too much, of course).

  19. #19
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    Quote Originally Posted by happyriding View Post
    Thanks for all the responses.

    I ended up adjusting the pads by feel. With the brake mounting bolts loose, I pulled the brake body away from the wheel so that the inside pad hit the rotor. Then I moved the brake body outwards in small increments, tightened the caliper bolts, and spun the wheel to listen for rubbing.

    The Park Tool website also has a couple of suggestions:

    Park Tool Co. » ParkTool Blog » Shimano® Hydraulic Brake Service and Adjustment

    The one that helped me finally get the front brake aligned was to only undo one of the mounting bolts and then pushing on that end of the brake body to move the pad slightly.

    Depressing the brake lever does squat. !@#$@!##@! Shimano for the shite instructions. Thanks mtbr for the real instructions!

    As for facing, my LBS said not to bother with the post mounts on the fork because they said the adjustment was going to be side to side. But they did face the rear brake mounts. The facing on the rear didn't make any difference: squeezing the brake lever, then tightening the bolts led to rubbing. I tried five times, and the brakes rubbed each time. Once again, I removed the brake pads and checked the pistons and they each protruded about 1mm just like in the front. So I ended up adjusting the rear brake by feel too.

    The reason I decided to remove both brake pads was because when I was mounting the levers on the handle bars, I gently squeezed the brakes while checking their position, and then I noticed that the orange insert had fallen out of one of them. I thought maybe the pistons on one of the brakes might be screwed up because of that.

    I have a question, there is a long thin bolt I unscrewed to remove the pads--it had a clip on the end of it. When I unscrewed that bolt it seemed to break free as if was glued in there--but the Park Tool website doesn't mention putting any loctite on there when reinstalling. Does that bolt need loctite?

    Now I'm watching for leaking brake fluid. I've got my fingers crossed.

    Oh yeah, after aligning the rear brake, I realized I needed to route the cable on the inside of the chain stay. Rather than remove the rear brake, I'm going slide everything off the bars and use the brake lever to route the cable. I want no part of adjusting the rear brake again!
    Check that bolt for tightness after every ride for a while. If it starts to loosen, use loctite, otherwise no need.

    I hate to break it to you but each time you have to remove a wheel, for a flat or to change a tire, you MAY (not for surely, though) need to do a slight caliper realignment. That's just part of the game...
    fee-fy-fo-fum...

  20. #20
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    After you've ridden the bike a few times, and bedded the pads in, it's often worth going back and tweaking the caliper alignment to make sure it's still running smoothly.

    For taking wheels on and off the trick is to get the skewer and wheel back into the same position that it was in when you aligned the caliper initially. When you take the wheels on and off the brakes will stay in alignment if the skewer tightness is exactly the same each time. If the skewer tightness is different between taking the wheel on and off then it changes the rotor position relative to the brake caliper very slightly, which can make the brakes rub.

    Systems like the Fox 15QR are good because the set number of turns means that you will reliably tighten the skewer back to the same tightness.

    The picture below shows the rotor / pad gap on my Shimano XTR M988 brakes. Your brakes should have a similar gap.
    Attached Thumbnails Attached Thumbnails I hate the new XT 2012 brakes-xtr_pad_gap.jpg  


  21. #21
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    Quote Originally Posted by WR304 View Post
    Holding the brake lever on and then tightening the bolts doesn't really work that well for aligning disc brakes. It's better to align the pads by eye. Assuming that your brake rotor is completely true (difficult to tell just by looking at them) then the easiest way to align brake pads is usually outdoors in direct sunlight. The sunlight shows up the small gap between the pads and rotor more clearly than doing it indoors.

    For the front brake if you turn the bike upside down so that it is resting on the saddle and handlebars then you can look down through the caliper and see the clearance between rotor and pad. Don't pull the brake lever whilst the bike is upside down. Part tightening the caliper bolts and then gently pushing the caliper sideways small amounts allows you to fine tune the alignment of the caliper with the brake rotor. By having the bolts part tightened it allows you to make fine adjustments to the caliper alignment.

    If the rotor is warped then you can true it by carefully bending it straight.
    .
    This is what I do, it's the only thing that works properly IMO.

  22. #22
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    Quote Originally Posted by jsilva View Post
    Glad you've got the alignment sorted out. Hopefully you'll come to enjoy your brakes It is surprising that Shimano continues to publish that method when it can easily not work. They should at least add a "If the pads continue to rub..."

    I've heard that the little clip doesn't matter. Plenty of people lose them without problems. Just make sure the bolt is tight (not too much, of course).
    I didn't loose the clip, my question was about the bolt. I removed the clip before unscrewing the bolt. It's just that it was really hard to unscrew such a small bolt, and it felt like it broke free--as if it was was loctited in there.

    For the first few rides, I will have to check every bolt on my whole bike because this is my first mtb build.

    Thanks for the "taking off the wheel" advice. After rerouting the brake cable on the inside of the chain stay, I had a heck of a time just getting my wheel back on. I have the rear derailleur and chain installed now, and trying to get the wheel around the derailleur while guiding the rotor into the brake caliper, and getting the drop outs to sit on my rear through axle proved almost impossible for me to do. It was a real struggle, and I had to abort my first attempt. When I finally got my wheel back on, I was sure I had knocked the rotor or brakes out of alignment, but I guess I got lucky.
    Last edited by happyriding; 10-01-2011 at 06:55 PM.

  23. #23
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    I've wondered why the caliper doesn't use jack screws, like on v brakes for spring adjustment, against the caliper bolt. It would sure help with adjustment and repeatability. I mentioned this years ago and got flack for it from someone. Am I missing something?

  24. #24
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    Quote Originally Posted by happyriding View Post
    I didn't loose the clip, my question was about the bolt. It was really hard to unscrew such a small bolt, and it felt like it broke free, like it was loctited in there.

    For the first few rides, I will have to check every bolt on my whole bike because this is my first mtb build.

    Thanks for the "taking off the wheel" advice. After rerouting the brake cable on the inside of the chain stay, I had a heck of a time just getting my wheel back on. I have the rear derailleur and chain installed now, and trying to get the wheel around the derailleur while guiding the rotor into the brake caliper, and getting the drop outs to sit on my rear through axle proved almost impossible for me to do. It was a real struggle, and I had to abort my first attempt. When I finally got my wheel back on, I was sure I had knocked the rotor or brakes out of alignment, but I guess I got lucky.
    The bolt holding the brake pads in place should be tight. The clip is an additional safety measure. You really don't want that bolt holding the brake pads to fall out as then you'd lose the brake pads also.

    Getting the back wheel into the frame with a disc brake takes a bit of practice initially. Whenever you take the wheel off make sure that the chain is in a lowish gear before you start - I'll usually use middle chainring and 1 up from the smallest rear sprocket (33T chainring x 12T sprocket). The more tension that there is on the chain the harder it is to get the wheel back into place so this makes it easier to do.

    With the bike upside down (resting on the saddle and handlebars) loop the chain back over the same small sprocket, and then rotate the entire rear derailleur backwards so that it's fully out of the way. You can now drop the wheel into place near the dropouts with one hand whilst the other hand holds the rear derailleur back. If you're lucky you'll be able to guide the brake rotor into the caliper straight away.

    If the brake rotor doesn't go in first time, let go of the rear derailleur and rotate just the spring loaded derailleur cage round by hand. This takes all the tension off the chain so that you can easily guide the disc brake rotor into the correct position. Without any chain tension it makes it easier to line up and drop back into place.

  25. #25
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    At some point, I am going to have to cut the rear brake hose to shorten it. Is there a simple way to do that to avoid having to bleed the whole system? I plan on doing some test rides before cutting the hose so that I know what the brakes feel like out of the box.

    The only thing I have left to do is put on the grips. Then I'll double check all the bolts, read about the adjustments for the shock and fork, and I'll be ready for a test ride. Oh yeah, I still need to take the tubes out of my tires and fill the tires with Stan's sealant.

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