[acrylucs]

I wouldn't, but i'm out of luck. I have done everything. I have cleansweeps. I have gone through several break pads and brands. I have been to my LBS like fifty times. I had them broken in properly so many times (its been 8 months) and still i have shuddering on my 2005 Avid Juicy 5's, 160mm.

Now, i look at the wear pattern on the disc, and its not grabbing the rotor arms (remember i'm on cleansweeps), and its not grabbing once per revolution, its a seemingly random shuddering which can shake my fork its so violent. Are my brakes doomed?! I have a different bike with Hayes HFX-9 8" rotors on my DH bike and those, albeit less modulation, are smooth and powerful (well, they're 8"). I can't stand these breaks. I feel like they're going to snap my fork and tear off my headset. They were mounted on a Specialized Epic, which is under warranty (and the warranty office for Canada is down the road from me) so should I demand a brand new set of Juicy's?

I hate AVID with a passion.

 

[XSL_WiLL]

It has something to do with the rotors then. They're probably hotspotted or poorly manufactured. Just sounds like a run of bad luck. They're actually very good brakes. I've run them on 2 bikes for almost 2 years now with no issues. I only used the polygon rotors very briefly (about a month) and have had no issues. I used them with both round and v-cut Hayes 203mm rotors, and am now running them with laser cut aluminum rotors. Don't worry, under aggressive riding, those HFX-9 master cylinders won't last long.

Try throwing the Avids on your DH bike (after resurfacing the pads).

 

[Jaji]

iono they work really well on my buddy's bike. he has no complaints. ive ridden it a few times and no problems. yeah i would talk to avid about your particular set of brakes.

 

[FoolCyclist]

Same Issues

Sounds alot like my Juicy 5. On the front it seems to work well, just lots of noise. The rear is a whole other story though. Horrible shuddering and really bad sounding. They'll stop me, but feels like the whole bike is shaking and I am sending out a mating call to the javelinas. Its not the normal disc brake howl, its entirely different.

I have tried everything that I have found on here about proper set-up and have gone with new rotors, pads, bleeds and rebleeds.... nothing changes for more than a ride. I refuse to have to bleed my brake for everyride. Right now I am running the clean sweep rotor in a 185 set up. I have tired new pads, filing pads, different methods of seating in the pads.... It all ends up the same. Even talking to Avid hasn't solved anything.

So, basically this is my last set of Avid hydraulics, luckily I work in a shop so I can replace them without setting back too much.

I really wish there was something that performed as well as the old XT four pots. Guess its going to searching the net for a pair of those bad boys.

 

[Jaji]

^ yup the old xt 4-pots are the way to go. with the second generation levers too.

 

[gunnar]

Here I thought I was the only one with noisy Juicys. I'm done with them and am going back to rim brakes. These brakes make my new custom steel hardtail so unpleasant to ride I'm not riding it until my LBS converts iit to a rim system. Yes, they were set up by a competent LBS who has factory support. Pure garbage.

 

[XSL_WiLL]

Not garbage. Bad rotors.

 

[zoomdrive]

Sounds all too familiar. I have Trek Fuel 80 with discs. The rear has been noisy (sounds like a goose honking under my seat) since day one. I had a Hayes hydraulic setup and tried three different pads, new rotors, cleaning, bedding in. Made no difference.
Must be the brake, right. Swapped for a Avid Juicy 5. Same noise right out of the box.
Since then, I have filed the pads to change the contact point. It actually worked to a good degree until I figured more filing would cure it for good. Nope. Full fledged honking.
My last trick was to use an automotive brake adhesive for the pad to the piston - no luck.

My last ditch idea has been to check the natural frequencies of the various parts that can make noise - the rotor, the rear triangle and the wheel. I found I can reproduce the noise by plucking on the spokes like a guitar string. My last try to fix this before the bike goes to the trash heap and be replaced by something with rim brakes is to have the spokes tightened. I seems that the wheel may be amplifying the vibration along the length of the spokes then broadcasting that mess through the entire frame. Tightening the spokes should change the natural frequency of the wheel, hopefully outside the range being excited by the brake. We'll see what happens.

 

[AndrewTO]

Not garbage. Bad rotors.

How about a compromise then, Will?

Garbage rotors.

Run of bad luck? C'mon man, you see how many people are posting with the SAME luck ..... that's a marathon, not just a run.

I REALLY hope Avid's new Juicy Ultimate aren't the same.

 

[AndrewTO]

Sounds all too familiar. I have Trek Fuel 80 with discs. The rear has been noisy (sounds like a goose honking under my seat) since day one. I had a Hayes hydraulic setup and tried three different pads, new rotors, cleaning, bedding in. Made no difference.
Must be the brake, right. Swapped for a Avid Juicy 5. Same noise right out of the box.
Since then, I have filed the pads to change the contact point. It actually worked to a good degree until I figured more filing would cure it for good. Nope. Full fledged honking.
My last trick was to use an automotive brake adhesive for the pad to the piston - no luck.

My last ditch idea has been to check the natural frequencies of the various parts that can make noise - the rotor, the rear triangle and the wheel. I found I can reproduce the noise by plucking on the spokes like a guitar string. My last try to fix this before the bike goes to the trash heap and be replaced by something with rim brakes is to have the spokes tightened. I seems that the wheel may be amplifying the vibration along the length of the spokes then broadcasting that mess through the entire frame. Tightening the spokes should change the natural frequency of the wheel, hopefully outside the range being excited by the brake. We'll see what happens.

Let me save you a step;

I agree with your thinking and i've already been down that road with a set of BB7's (both Type F and Type N). No luck. I said "screw it" and went back to v-brakes since. I lost patience and needed to ride.

IF you wanna try something that would really be a big change in resonance then try using small pieces of fabric between where the spoke's cross. The fabric will act as an insulator and would instantly change the resonance of the wheel. I never got around to this, but you might want to give it a try. That, or go the old throw-back route from the '80's/'90's and tie/solder the spoke's where they cross.

Obviously you wouldn't want to use this full time, but it would be a quick indicator of success or failure of the theory.

 

[XSL_WiLL]

How about a compromise then, Will?

Garbage rotors.

Run of bad luck? C'mon man, you see how many people are posting with the SAME luck ..... that's a marathon, not just a run.

I REALLY hope Avid's new Juicy Ultimate aren't the same.

Most of the time it's attributed to improper initial setup and then making the problem worse by using unevenly worn pads with new rotors. Sometimes you get crappy rotors that were manufactured to uneven thicknesses. I have dealt with ONE such case thus far.

 

[gunnar]

One of the reasons I got into biking was to enjoy a simpler, less problematic machine. I had spent thousands on snowmobiles and Jet-Skis to get them to run and I was tired of it. Now I have a bike with brake problems, the one system that should be perfect, IMO. Disc brakes on a XC machine are overkill. I believe the industry is pushing them because it builds new interest in the products, kind of like aluminum frames did way back when they were all made from steel.