Need help--how to adjust caliper/pads on Avid Elixir 5 brakes
Recently I purchase a Scott Scale 29er (two weeks ago) It came with Avid Elixir 5 brakes. The front brake works well, disc is aligned properly, and the wheel spins nicely.
The rear, however, is squealing and is rubbing against one or both of the brake pads (spin it and it comes to stop in a few seconds). The disc seems in good condition, and not warped.
I wiped the disc with alcohol, and that seems to have helped a little bit. However, it's still rubbing.
I would like to adjust it to 1) stop the rub, and 2) stop the squeal.
How does one adjust it? Is there a toe adjustment? There are many bolts on the caliper. Two that hold the caliper to a bracket that is attached to the frame of the bike. Those bolts have spacers that can be changed around. And there are two others that seem to hold the two halves of the caliper together. And then one smaller bolt which appears to hold the brake pads in place.
Anybody know how to make the adjustment? Seems kind of complicated...Is there a website with pictures? (The Avid stuff is pretty useless--no information on adjusting, just lots of stuff on bleeding the lines, etc)
Thanks for any advice you can offer.
Mac & Jacks African Amber
lossen said bolts so that the claiper "floats". Then squeeze brake handle several times and hold in place firmly while you tighten the bolts that hold the caliper. this allows the spacing to be set properly.
My Current Rides:
'09 Trek 69er SS '08 Trek 69er 3x9 HT
That should take care of it.
If it doesn't, try having the frame's mounting bosses for the rear caliper faced so the brake caliper, when mounted on the frame, is properly aligned with the rotor attached to the wheel. I had a similar problem on another frame. Facing the frame's brake caliper mounts solved the problem.
It requires a special tool to face the brake mounts on the frame. Check with your LBS to see if they have the tool....most well-equipped shops do.
Virtus pre nummis
Here you go! From Park Tools. Their website link:
And here are the instructions, but for pictures you will need to go to their wqebsite.
AVID® MECHANICAL DISC ADJUSTMENT
This article will discuss the service and adjustment of the Avid® mechanical brake systems. For information on the disc rotor mounting and service, see Rotor Mounting and Serivce.
Disc brake systems use a caliper mounted near the dropouts of the frame or fork ends, and a rotor (disc) mounted to the hub. The brake pads are housed in the caliper and are forced into the rotor. Disc caliper brakes slow the bike by converting the speed and energy of the bicycle into heat. Disc brakes can be effective in wet weather where mud, dirt and water are a concern in braking. The system can generate significant heat from slowing the wheel and bike. Allow rotor and caliper to cool before touching or servicing.
Mechanical disc brake systems use calipers that are cable actuated, similar to rim caliper brakes, with an inner brake wire and housing pulled by a brake lever.
Disc brake calipers mount to fittings on the bicycle frame and fork. The common standard is referred to as the International Standard. This standard uses two mounting holes spaced 51mm apart and the caliper mounting bolts are positioned perpendicular to the rotor face. A less common mounting system is the post mount. The mounting bolts of the post mount are parallel with the rotor faceand the mounting holes are spaced 74mm apart. Brake calipers designed for the post mounting system can be fitted with adapters to work with the International Standard.Brake pads for both mechanical and hydraulic systems are available in various compounds. Generally, a softer resin material will tend to squeal less. It will also offer the user more modulation, or the ability to brake lightly. However these types of pads will also wear more quickly. The harder metal or semi-metallic pads will last longer, especially in wet and muddy conditions
The rotor or disc of the disc brake system secures to a disc-specific hub. The common system uses six bolts. Use a mild thread locker on the threads, and secure the bolts. Many brands use rotor bolts requiring the use of a Torx T-25 wrench. A Torx fitting is a special 12-point socket head bolt. Secure rotor bolts to manufacturer's torque specifications .
Mechanical Disc Brakes
Mechanical disc calipers use two brake pads, one on each side of the rotor. Depending upon the design of the caliper, both pads may move to contact the rotor. However, alternative designs have one pad being fixed, with only one pad moving to contact the rotor. With this design, the rotor will flex to push against the fixed pad when the brake is used.
Flat handlebar brake levers used with mechanical disc calipers are compatible with the linear pull caliper rim brakes. The lever should be set for a comfortable reach and secured to the bar. The brake housing and brake wire are the same as with rim caliper brakes. Prepare housing and wires as with rim caliper brakes.
Avid® Brake Caliper Adjustment
The Avid® caliper design is to have the inner pad-to-rotor gap about twice as large as the outer pad-to-rotor gap. It can be
difficult to measure and achieve this ratio, but the brake will still perform even if the ratio doesnot achieve this exact proportion.
The outer pad moves toward the rotor when the caliper-actuating arm is pulled by the brake wire. The inner pad can be adjusted toward or away from the rotor with a pad-adjusting knob, but it is fixed during braking. The moving pad flexes the rotor toward the fixed pad when the brake is operated. The moving outer pad also uses an adjusting knob to position the pad relative to the rotor. The dial uses an indent system, with 16 per revolution. One complete revolution moves the pad approximately 1mm.
The Avid® mechanical disc brake for MTB bikes uses a brake lever designed for linear pull brakes. Pad adjusting knob moves pad position relative to rotor. Avid® disc caliper brakes use a ball-and-socket system for the caliper mounting bolts. This fixing system is similar to many brake pads on linear pull caliper rim brakes. This system allows easy alignment of the brake caliper to the rotor.
The procedure for Avid® mechanical caliper pad alignment is as follows:
1. If the caliper is attached to an adapter bracket, check that the bracket is fully
secured to the frame or fork.
2. Loosen caliper-mounting bolts so the caliper is loose on bracket or post mounts.
3. Slacken cable with adjusting barrel or loosen brake wire pinch bolt if it is secured.
4. Check that both pad adjusting knob dials are turned fully counter-clockwise to move pads fully away from rotor. Turn the outer pad-adjusting knob approximately 1⁄2 turn clockwise.
5. Turn the inner pad-adjusting knob clockwise until inner pad fully secures and locks rotor. This aligns caliper body and pads to rotor face.
6. Snug each caliper-mounting bolt. Alternate turns to tighten one bolt and then the other until both are fully secure.
7. Draw slack from the brake wire and secure pinch bolt. Do not allow caliper arm to move upward when drawing slack from brake.
8. Set pad clearance. Loosen outer padadjusting knob approximately 1⁄4 turn counter-clockwise. Loosen inner padadjusting knob approximately 1⁄2 turn counter-clockwise. Inner pad (fixed pad) to rotor gap should appear larger than the outer pad to rotor gap.
9. Squeeze lever to test caliper brake. Adjust lever modulation setting by moving pads inward or outward from rotor by using both pad-adjusting knobs. To maintain the 2:1 ratio, turn the fixed pad-adjusting knob twice as many clicks as the moving pad-adjusting knob. For example, if a looser modulation is desired, turn the inner pad-adjusting knob counter-clockwise 4 clicks and the outer pad adjusting knob counterclockwise only 2 clicks.
The caliper-actuating arm is designed to operate from a fully open position. Set cable tension at the adjusting barrel so actuating arm
is fully opened or returned. Do not use the brake lever adjusting barrel or cable pinch bolt to account for pad wear. Caliper arm may bottom out on caliper body and prevent the pads from pressing on rotor.
As pads wear, use pad-adjusting knobs to move pads closer to rotor. Turn the fixed pad adjusting knob clockwise twice as many clicks as
the moving pad adjusting knob to maintain the 2:1 ratio of pad to rotor spacing. For example, if the inner (fixed) pad-adjusting knob is turned clockwise two clicks, turn the outer (moving) pad-adjusting knob clockwise one click. Brake pads should be removed and replaced if the pad thickness, including the metal holder, is less than 3mm.
Avid® Mechanical Brake Pad Removal and Replacement
As the bike is ridden and the pads wear, do not use the brake lever adjusting barrel or cable pinch bolt to account for pad wear. Caliper arm may bottom out on caliper body, preventing pads from pressing on rotor. Use pad-adjusting knobs to move pads closer to rotor. Turn the fixed pad adjusting knob clockwise twice as many clicks as the moving pad adjusting knob to maintain the 2:1 ratio of pad to rotor spacing. For example, if the fixed pad adjusting knob is turned clockwise two clicks, turn the moving pad adjusting knob one click.
Avid® mechanical brake pads should be removed and replaced if the pad thickness, including the metal holder, is less than 3mm.
The procedure for Avid® mechanical caliper pad removal and replacement is as follows:
Mount bike in repair stand and remove the wheel.
Loosen each pad adjustment knob an equal amount.
Grab lever at end of pad and push toward center of caliper body, pulling pad outward and away from caliper. Repeat process for second pad.
Push lever to center of caliper body and lift to remove. Note orientation of pad return spring and remove spring from pads.
Place new pads over pad return spring. Spring should be sandwiched between new pads. Installation lever is set asymmetrically on pad.
Align bridge of spring with caliper boss locators. Gently squeeze return spring and pads. Engage pads into caliper body. Pad installation lever orients away from brace bolts. Push return-spring and pads into place. Pad locator will engage bosses in caliper boss.
Push pads into caliper body.
Old age and treachery will overcome youth and skill!
I am sure there is an instructional video on youtube for adjusting elixir brakes.
Thanks to everyone for the replies. I loosened the two mounting bolts, squeezed the brake, and then tightened them. It does seem to be binding less. Will test ride soon to see what effect it had.
Longview tx, I adjusted the bolts you suggested, squeezed the brake and voila, I got covered in hydraulic fluid. What's the deal?
You must have loosened the wrong bolts. Its not possible for fluid to come out from loosening the caliper from its mount. The brake will function normally in every way when you do what he said.
Originally Posted by Jafs1664
There is no need to face mounts with Avid's Tri Align system thankfully I've used it on seriously useless frames and it squares up to the disk personally.
As post 2 the only thing I can add is, do the bolts up slowly in stages alternating between the 2, if you do 1 up tight on it's own it'll turn the caliper slightly and knacker the alignment.
Also with the bolts loose push the bike and squeeze the lever letting it drag this helps the pistons re align themselves to centre, you might have to push both pistons back in fully then pump the lever to get them out, cause being out of line might have pushed 1 piston out to far.