I have a Trek X-Caliber and the rear disc is rubbing a little. So I want to adjust the brakes so it doesn't rub and make things a bit easier of course.
I see many videos about brake adjustment but none for this model (Avid Elixir 1) and I am very worried about playing around with the system and then end up making things worse...or with no rear brakes at all.
I live in thailand and there isnt a good bike shop where i live.
The manual says they are self-adjusting but a shop told me you can adjust them slightly by loosening the rear caliper from the frame, squeezing the brake pedal gently, and tightening the caliper back down to the frame (to specs of course). Also, be sure not to loosen the screws holding the two sides of the caliper together, otherwise you'll let the fluid out and air in.
I've spent a lot of time adjusting Avid Elixir 5 brakes to stop rubbing. There could be multiple things going on that may need to be fixed. If you can figure out which of these applies to your situation, I can give you more detail on how to fix it. Below are 4 possible causes of your brakes rubbing, and what to do about it.
If the disc is warped, you can bend it back into shape. Hold the bike so you can spin the wheel and look closely at the tiny gap between the rotor and the pad on each side. It may help to put a light-colored object, such as a white piece of paper, underneath, so you can see it through the gap. Good light helps too. As the disc spins, you may be able to see that the distance from the disk to the pad on one side increases and decreases. When it gets too close, it rubs against the pad. Spinning the disk slowly, you can see which part of the disk is bent towards that pad. By gripping that part of the disk with an adjustable wrench (or a specialized disk truing fork, if you have it), you can gently bend it in the opposite side and straighten it out.
Or maybe the problem is that the brake caliper is not centered properly. This is the case if one pad is rubbing against the disk for most of one revolution of the wheel, and there is a gap between the other pad and the disk. This can be fixed by loosening the caliper bolts (2), moving the caliper so the disk is centered between the pads, and tightening the bolts again. The gaps are tiny, so you only want to move the caliper by an amount similar to the thickness of a few pieces of paper (maybe 0.1mm ?). It is easier to do this if you only loosen the caliper bolts a little bit -- just enough so you can move the caliper, but not so loose that it moves too much.
Be careful when you are done adjusting and tighten the caliper bolts. Turning the bolts with a hex wrench can move the caliper, which would ruin whatever adjustment you have just made. I found I can avoid this problem by firmly holding the caliper with one hand while tightening the bolts with the other hand. Also, tighten each bolt a little bit at a time, going back and forth between the two bolts. Carefully watch the gap between the disk and the pads; when the gap changes, you know you've screwed up.
The third possibility is that there is too much brake fluid in the system, which prevents the pistons from retracting enought to give sufficient space between the pads. Remove the pads and try to push the pistons all the way into the caliper. If they go all the way in, it's fine. If not, you need to remove a small amount of brake fluid through one of the bleed screws, but not too much.
Another possible cause is that the pistons are unable to retract sufficiently when you release the brake. This can happen when brake dust and other dirt accumulates on the pistons near the seals (where the pistons retract into the caliper). You can fix this as follows: remove the wheel and the pads. Clean the area inside the brake caliper where the pistons are (using a small brush or similar). Pull the brake lever and watch how the pistons move. If they both come out and then retract, they are fine. Don't push the pistons too far, or you will get air into the system and then you will have to bleed the system (this is a bit complicated and time-consuming). Push the pistons back in, as far as you can. If one or both of the pistons are stuck (meaning they don't retract when you release the brake lever), you can get them unstuck by putting a few drops of brake fluid on the edge of the pistons (where they touch the seal). Then repeatedly push them out a bit using the brake lever, and push them back in using a tire lever or similar tool made from wood or plastic. I've read that a metal tool might damage the pistons, but I'm not sure if that's true.
Got elixir 1 (due to low price) to replace my 12 years old Hope Mini where the rotors did not move anymore. Those things worked 11 years with just replacing pads - mostly light city riding. And the front is still working nicely.
Googled for a solution to adjust the pads as they were tight on the rotor. Solution: suggested on SRAM's web page prior to bleeding - just pulling the lever several times to "reboot" the caliber. Worked when I was pulling the lever with full force and at the same time pedaling a bit forward. Now there is maybe 5 mm of movement before the pads make contact.
So operation seems similar to Hope Mini - self-adjusting etc. Hopefully this individual does not need bleeding too often (like the Mini) - opposite to the horror stories in the web (bleeeding every month or at least every 3 months).
