# Brakes Will Not Stay Aligned



## RoadBoy1 (Oct 1, 2011)

I have a recurring problem with dual pivot calipre road brakes not staying aligned and one pad or the other starts rubbing the rim causing unneeded and unwanted drag. This has happened with just about every set of dual calipre brakes (front or rear calipre it happens to both) I have ever had on any bike I have ever owned and I am starting to get really irked.

It doesn't matter if the brakes are Dura-Ace, Ultegra, 105, or any other brand of dual pivot calipre brake; it happens to all of them. The fixing bolt is tight and I use the small 2mm allen bolt to center the calipres but they never stay centered. Sometimes it only takes a hundred miles to have the calipres to go out of center and I wind up riding with one side of the brakes on. Understand that I am a fan of resistance training but I prefer not to wear out a rim prematurely.

This never happened to me with the single pivot calipres and I actually preferred the single pivot calipres to the dual pivot ones any day of of the week. They had much better modulation and were a whole lot simpler in their design and execution. The only thing they lost to the dual pivot calipres was a little bit of braking force and I was always taught that the object of riding my bike was to go and not stop and if you ride with a little bit of caution and sense you will never need to jam on your brakes and make a panic stop.

Has anyone else had the problem of dual pivot calipres not staying centered? What did you do to correct it? Thanks guys.


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## robdamanii (Feb 13, 2006)

Shorten the brake cable housing?


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## brucew (Jun 3, 2006)

Check that the mounting nut isn't bottoming out on the mounting bolt or in the fork or brake bridge.

The nuts are not a universal length. They come in different sizes. If you're tightening them down to spec (6–8 Nm for Shimano) and they're still moving like that, then that's likely the problem.

I had exactly that same situation on a second-hand bike I bought. Replacing the caliper mounting nuts with shorter ones did the trick. I also bought a torque wrench and discovered that I hadn't been tightening them enough either. And bear in mind those torque specs are for lubricated threads. If there's corrosion or tightness when screwing the nuts on outside the fork/brake bridge, clean them up then lube them.


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## cxwrench (Nov 9, 2004)

never really had a problem w/ this...you sure the nut is tight enough and the correct length?
maybe the housing it too long, but it might be too short and pulling the brake. should pretty much be a no-brainer. mount brake...tighten nut...center.


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## Special Eyes (Feb 2, 2011)

Dual pivot brakes were designed to reduce the exact problem you have, but it never fully goes away. I have to fine tune my brakes every time I put a wheel back on. Pretty standard stuff. Only takes a moment. Like others have said, check your main bolt tightness and keep them clean and lubed.


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## cxwrench (Nov 9, 2004)

Special Eyes said:


> Dual pivot brakes were designed to reduce the exact problem you have, but it never fully goes away. *I have to fine tune my brakes every time I put a wheel back on.* Pretty standard stuff. Only takes a moment. Like others have said, check your main bolt tightness and keep them clean and lubed.


you have to do that when you're putting the SAME wheel back on? you shouldn't have to do that...
but as you said, it's very easy.


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## FBinNY (Jan 24, 2009)

Like the OP, I still prefer single pivot brakes, but dual pivots should be 100% bulletproof reliable as far as centering goes. Obviously something is going on, so lets start with basics, the most important of which is correctly mounting wheels.

1- *Always* mount the wheels with the bike vertical on the ground. *Let gravity drop the frame so the axle is fully pocketed at the top of the dropout.* This will ensure that mounted wheels always returns to the same position. This is the wheel's home position and the brake centered accordingly, not as many do centering the wheel in the brake. If the wheel isn't fully in the dropout it can move up on a hard bump changing the position. 

2- related to the above, make sure you don't have a bent axle. Bent axles will move the rim sideways randomly depending to the axle's orientation. If you're not sure, hold the bike vertical with the QR open. Use a cone wrench or pliers to slowly turn the axle while watching the rim between the brake shoes. if the rim moves, the axle is either bent or worn where it meets the dropout, and you won't get consistent wheel positioning.

3- make sure the brake bolt can't move on the frame or fork. Serrated washers help, but can be come indexed where they bite. that's OK, and you shouldn't fight it as long as you can fine tune via the balancing screw. Otherwise keep the bolt from moving with a sandpaper sandwich (2 bits of sticky sandpaper glued back to back, with a hole punched in the middle) or with coarse lapping compound behind the bolt. Either will bite and ensure that the bolt cannot move.

4- check that the cable housing is measured to a relaxed length. Overly long housing pushes the arm down, short housing pulls it up. This is probably the biggest factor on smaller frames where the loop can be short and stiff. If the housing can slip on the frame, secure it so housing movement doesn't change the length of the rear loop.

5- keep pivot arms and spring rests on the arms lightly oiled. The centering spring isn't that strong and a bit of friction at pivots or where the spring slides will change the balance.


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## Mr. Versatile (Nov 24, 2005)

Mine need to be adjusted occasionally. Mine get knocked crooked from the bike being carried around in the car. I'm also a fan of 25mm tires & they're a bit hard to fit through the brakes even though the quick release levers are open. It doesn't bother me much. After removing the bike from the car or replacing a wheel I just lift up one end of the bike & spin the wheel. If the brakes drag I just put one hand on each side of the brakes on the shoes & adjust them with my hands. No big deal. Picking up the bike & spinning the wheels should be a part of a quick pre ride safety check anyway.


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## danl1 (Jul 23, 2005)

Mr. Versatile said:


> Mine need to be adjusted occasionally. Mine get knocked crooked from the bike being carried around in the car. I'm also a fan of 25mm tires & they're a bit hard to fit through the brakes even though the quick release levers are open. It doesn't bother me much. After removing the bike from the car or replacing a wheel I just lift up one end of the bike & spin the wheel. If the brakes drag I just put one hand on each side of the brakes on the shoes & adjust them with my hands. No big deal. Picking up the bike & spinning the wheels should be a part of a quick pre ride safety check anyway.


This is my experience, too. I never have a problem unless they get knocked somehow, and if they do, I just put a palm across the top of 'em and shove 'em over a little bit. I've never used the little centering screw other than for the sake of playing with it.


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## FBinNY (Jan 24, 2009)

Mr. Versatile said:


> Mine need to be adjusted occasionally. Mine get knocked crooked from the bike being carried around in the car. ... After removing the bike from the car or replacing a wheel I just lift up one end of the bike & spin the wheel. If the brakes drag I just put one hand on each side of the brakes on the shoes & adjust them with my hands. ...


I think we all run into this, but I suspect that the OP is referring to brakes that go off center on their own and don't stay centered after being tapped home. 

My commuter has canti brakes and they go off center and I can usually correct them by sliding the carrier on the yoke cable. But it has a preferred home position and will work it's way back there over time, so I try to set the balancing cam (old brakes) so they center best in the home position.


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## Newnan3 (Jul 8, 2011)

Reviving this old thread because Ive been trying to figure out what that little [email protected] centering screw on Shimano dual pivots does.....Can anybody tell me when I need to mess with it?

I dont have as extreme a problem as OP but I do notice my brakes are off-centered right after I adjust them by hand sometimes.


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## cxwrench (Nov 9, 2004)

Newnan3 said:


> Reviving this old thread because Ive been trying to figure out what that little [email protected] centering screw on Shimano dual pivots does.....Can anybody tell me when I need to mess with it?
> 
> I dont have as extreme a problem as OP but I do notice my brakes are off-centered right after I adjust them by hand sometimes.


pretty every mechanic i've ever known or worked with completely ignores the 'brake centering bolt' and just moves them by hand. if they don't stay adjusted after you move them you probably just need to tighten the mounting nut. they're pretty simple, it can't really be anything else. 
here's the techdoc for brakes...
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/BrakeSystem/SI-8FA0H-ENG_v1_m56577569830605105.pdf


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## FBinNY (Jan 24, 2009)

Newnan3 said:


> Reviving this old thread because Ive been trying to figure out what that little [email protected] centering screw on Shimano dual pivots does.....Can anybody tell me when I need to mess with it?
> 
> I dont have as extreme a problem as OP but I do notice my brakes are off-centered right after I adjust them by hand sometimes.


The small adjusting screw on top is a fine adjust for centering the brakes. Dual pivot brakes stay centered very well, so if they aren't staying centered you should look for another cause.

Start by making sure your wheel position is centered and will repeat. The best way is to mount wheels with the bike upright on level ground. Allow gravity to position the dropouts fully down on the axle, possibly with a small jiggle to assist. Then close the QR. Now reset the adjustment screw so the arms are roughly level on top. Loosen the mounting bolt, center the brake by eye and retighten. Test by pushing down one side to make sure the mounting is secure. Finish by using the adjusting screw to fine tune the centering.

Note, if the brake moves when you force it, odds are that the nut is running out of thread preventing you from properly tightening it against the frame or fork.


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## Newnan3 (Jul 8, 2011)

Ahh, i was using the quick release as a fine tune adjustment for the brakes vs turning the barrel adjusters. 

I think the mounting bolts may be too long as Im not able to tighten them anymore. It appears that the brakes misalign only when i turn the handlebars at an extreme angle. This probably happens when I place/remove the bike out of the back of my car.


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## FBinNY (Jan 24, 2009)

Newnan3 said:


> Ahh, i was using the quick release as a fine tune adjustment for the brakes vs turning the barrel adjusters.
> 
> I think the mounting bolts may be too long as Im not able to tighten them anymore. It appears that the brakes misalign only when i turn the handlebars at an extreme angle. This probably happens when I place/remove the bike out of the back of my car.


If your caliper moves at all it's not tight enough. Take it off, thread the nut to the bottom and compare to the thickness of the fork. If it's borderline, use a file to shorten the nut slightly, say about 1/32". You shouldn't need more since if the nut was seriously too long it would be obvious. 

As I said earlier, you shouldn't be able to move the brake by hand no matter how hard you try.


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