Hydraulic brake adjustment question

[sethschmautz]

Hey guys,

On the last two bikes that I have owned (for approx the last 8 years), it seems like I have needed to adjust the hydraulic brakes before just about every ride to prevent rubbing. Before a ride, I'll put the bike in the stand and adjust until there is no brake rub, but by the time that in back home (probably sometime mid ride) they are rubbing again. Typically it's minor, but occasionally it's major.

Any idea what's going on? Wheel flex? Brake assembly moving?

Typically the front wheel. I'm currently riding Stan's Arches on a specialized Epic.

Thanks in advance.

Seth

[TBS]

Maybe if you mentioned the model of brakes you are constantly adjusting?
And whether front hub is thru-axle or QR?

[SHITACK]

What brakes do you have? Does your fork have q/r or thru axle?

[sethschmautz]

In both cases, QR. The last bike was a set of Hayes Nines. Currently, avid elixirs.

[Eluder]

Do you take the front wheel off frequently and is it a cheap skewer?

[detrusor]

Sounds like a sticky piston. If your not comfortable bleeding and taking apart have the shop do the work.

[sethschmautz]

Front wheel came off much more frequently with the Hayes, not as much with the acids, but a bit.

Probably not the highest quality skewers.

I have bled the brakes before and have the tools to do it, but it has been a while.

How do you fix a stuck piston?

Seth

[XXX-er]

In both cases, QR. The last bike was a set of Hayes Nines. Currently,
avid elixirs.

no experience with elixir but hayes 9's are some very old 1st gen shit that wasn't very good when they were new

[TBS]

I, sadly, have experience with elixirs. They suck. There is no adjustment. You can rebuild the calipers till the cows come home and it won't make a bit of difference.

I kept mine from rubbing by sanding down about half of the brake pad thickness to create sufficient space for clearance. You can help the alignment of the rotor and pads by loosening the bolts where the rotor assembly attached to fork/rear swing, pulling brake and holding closed with strap, then tighten blots again.

The best solution - buy a pair of XTs.

[jimmyjames11]

^^^yep. Buy some xt's

[El Chupacabra]

I thought the solution was carbon fiber rotors. Pm canwilf

[Eluder]

To make sure your piston is stuck or not lightly pump the brake and see if the piston moves out and back. they will only move in if they are stuck. There are a couple things you should do at this point if its working properly. Remove your pads and pump your pistons so they are a little proud of the caliper just be very careful you can push the piston all the way out then you have some problems that most likely will require replacing parts. With rubbing alcohol and a q-tip clean the caliper and pistons. Then with a new q tip lightly oil the piston with dot fluid, next reset the pistons back in the caliper. Pedro tire levers or something similar work well for this. If you have an old set of pads installing them then using a flat blade screw driver works as well. Also be very careful pushing on the pistons they are ceramic and will crack sometimes even if your careful. Re-clean the caliper then bleed the brake as usual.

If your pistons are not retracting you need to replace the seals. If you have an air compressor and a air gun with a rubber tip this isn't to bad of job. After removing the pads I pump the brakes with the caliper over a bucket. One of the pistons will pop leaking the fluid. With gloves disassemble the caliper. the side that you have piston in still will need the air gun to force it out. Make sure you cover it with a rag as you will aerate brake fluid and send the piston flying. Eye protection is a must. Replace all the seals with the proper kit from avid and put the caliper back together. Bleed the brakes and your good to go.

Properly maintained Elixirs will work. If it seems easier to buy new brakes then just do that. Shimano doere level and up all pretty much work the same.

[Eluder]

The random adjusting could very well be the shitty skewer. Equal tension on the quick release is vital to keeping these from rubbing. My preference is shimano skewers.

I've ran elixirs since they came out with them with a couple sets of XT's in the middle. I have never had an issue with rubbing, if there is rubbing there is something wrong with them or more likely they are not adjusted properly.

[TBS]

Ok, I'll bite. Where is this adjustment mechanism on an elixir?

[Eluder]

Ok, I'll bite. Where is this adjustment mechanism on an elixir?

Its not a mechanism as you know. They adjust just like any shimano brake, through oil volume, caliper bolts and truing the rotor of course. Avid clearance is no better or worse than shimano. Avids take way more work to bleed than a shimano but get all the air our then adjust by how much oil you have in the system just the same.

[jamal]

I had to re-center my caliper fairly frequently with elixir 9s, and I found I could do a better job by eye than the auto centering bolts would do.

Also if the rotor is out of true it will be harder to have not rub.

As far as adjustment goes some of the avids have a contact adjust which moves the master cylinder relative to the lever so you can compensate for the amount of fluid in the system/pad wear. Personally I had to keep them dialed all the way in to get the brakes to feel decent. Now I have guides.

[TBS]

Its not a mechanism as you know. They adjust just like any shimano brake, through oil volume, caliper bolts and truing the rotor of course. Avid clearance is no better or worse than shimano. Avids take way more work to bleed than a shimano but get all the air our then adjust by how much oil you have in the system just the same.

XTs provide a lot more clearance betw rotor and pad than elixirs.

I agree that elixirs are more work to bleed

[Eluder]

XTs provide a lot more clearance betw rotor and pad than elixirs.

I agree that elixirs are more work to bleed

maybe my eyes are better than yours.

I adjust my shimanos to have low clearance because they have to long of a lever throw for my preference.

[TBS]

Little doubt about that.

And yet, I have (like many) had major issues with rotor/pad alignment/clearance on elixirs, but none with XTs.

Maybe it's just that I'm not willing to fiddle forever to gain a gnats eyelash of clearance

[sethschmautz]

This is great info. Thank you!