bigp399

I am installing a set of Juicy 3 disc brakes on my MTB, and I'm really having a hangup with the front caliper adjustment. Apparently it's a very easy process, and I followed the simple directions, but I still get brake rub when I spin the front wheel. The manual's only suggestion for dealing with brake rub is to "repeat." It doesn't seem to indicate what I am doing wrong. I'm basically loosening the appropriate bolts on the caliper, then squeezing the brake lever (and holding) and then tightening the bolts. Not sure where the error here is, but I repeated about 30 times last night for 2+ hours, and it wasn't happening. The rotor appears straight to my eye, and I got nothing else. If anyone knows of some common mistake I may be missing, please let me know, because it's killing me and it's the only thing left before riding my bike.
Thanks

Teboner92

is it a constant rubbing or a rub every once in a while? either your rotor is bent a little or something else to do with adjusting your caliper.

Bike Lover

Not trying to be a smart *** here, but are you required to shim the caliper from the fork? I never put Juicys on before but both the Maguras and the Shimanos require shims.

Chris_F

My rear rubs a little (Avid brakes). It's audible but doesn't appear to cause any undue drag on the wheel (wheel spins freely). I couldn't get it to stop the audible rub (backed the pads out entirely, removed the cable, nothing worked). Took it to a decent bike mechanic (local guy with good reputation) and he said that the audible rub is no big deal. You want the pads to float close to the disk, and if the disk isn't perfectly straight the pad my brush against it every now and then. The inside pad doesn't move, the outside pad presses towards the inside when you pull the lever, and if you back the inside pad out too far then the disk will bend when you apply the brake (the outside pad pressing the disk inward to the inside pad). It's better that the inside sit close, and sometime that means rubbing a little... Well, at least that's what the mechanic said.

Does your wheel spin freely or does it drag?

victim

Shim it. As thin as possible. Wheel should spin freely.

Drunken Chicken

To those recommending shims: it's not a bad idea, but the concept behind Avid's CPS is that you shouldn't need shims. Just keep trying, eventually you'll get it to zero drag; it took me a long while on my Juicy 5s.

mcoine

Loosen bolts on caliper and then squeeze/let go a few times.. then squeeze and tighten bolts.

victim

Until I shimmed I had to reset the brakes every time I went riding. After shimming I haven't had to do it once. I had to shim both wheels. Every bike is differnent though, so maybe you get it without the shims.

Trekbikedude

C'mon guys.

First off, is your wheel center in the dropouts?

a2psyklnut

Easiest solution. Go to an auto parts shop and get spark plug shims. Get the kind that are different mil strips of metal that fold like a mini-tool.

Slide those between your pads and rotor (inside - non moving side) and viola! No more fiddling with it!

yotool

Insert shim between pads and rotor??? That doesn't make any sense.

I had the same problem w. both front and back calipers of my Juicy 3's.

One poster is correct. Start by verifying that your wheel is properly centered in its dropouts as a baseline. Make sure your pads and /or pistons aren't hung up by crud buildup and that your little stainless steel return spring is there, inserted properly, and in good shape.

Verify that the rotor isn't significantly bent, or warped. By design, there isn't much "wiggle room" in the calipers when in the "released" position; so even a little bit of rotor warp will generate rub even when the calipers are properly adjusted.

However, I, like you, tried the loosen caliper, apply brakes, and while keeping them applied, re-tighten and it didn't work for me either; no matter how many times I tried, or whether or not I applied, released, applied while the calipers were loose...

What I did to get 'er perfect was to loosen the caliper mounting bolts, and using a small flashlight, eyeball an equal gap between both the inner and outer pad surfaces and either side of the rotor when the lever is kept in its released position (brakes not applied). While holding that caliper position with your hands, tighten the caliper mounting bolts without moving the caliper mounting position you had.

Free spinning nirvana now when brakes are released...

nachomc

This is the only way I can get my Juicy 5's not to rub also. The "CPS" just doesn't work right for me.

Zan

Hey!

I haven't read other posts, so I'm sorry if I'm repeating what others had said.

One thing you can try is to recenter the wheel. Sometimes people put 'em on at a slight angle, and that'll cause a problem with the brakes. No disrespect in mentioning it, but it could be a possibility.

Second thing you can check is make sure the pads are in the right spot. I've worked on my Avid 3's before and realized my problem once was that the pads weren't mounted properly in the caliper. Silly me, maybe silly you?

After you've fiddled around with those things you can try what you were doing before with the loosening, squeeze, tighten dealy.

Still no luck? Just try giving the bike a spin down the road. Grind the bajeezus outa the brake pads and see if that fixes it. You know, just ride down the the road in a low gear with the front brake applied and come back.

My brakes still rub up against the discs; i can't get it perfect. Spins kinda freely, though!

ca7erham

The whole loosen bolts, squeeze, tighten bolts works quite well. Also, if the brakes are new, see what happens after you get the pads bedded.

ca7erham

My rears do the same, but I dont notice any extra drag from it over the drag from my FK'd hub.

Lebowski

some times the automatic pad adjusters(w/e its called) get weird.

you can put a credit card between the rotor and the pad and squeeze the lever hard. sometimes that fixes minor rubbing problems

Zan

yeah i think my hubs are shot too. Not too sure why... I don't do drops really. I took 'em apart and re-packed 'em and they still cause a huge amount of drag. Worse than cheepo hubs i've had on previous cheepo bikes.