[denjen]

Just got a new bike. It came with Juicy 7's. Great brakes they have a great feel and a lot of power. Problem is the rear came with the 180mm rotor and I can feel the rear brake pumping up and starting to squeal about 3/4 of the way down every run. After it cools down it is fine but does it again on the next run. Will getting the 8" rotor make that big of a difference in keeping things cooled down?

Thanks
Dennis

 

[Spunger]

Well........I have 8" front/6" rear on one bike and 8" both F&R on another........the 6" rotor in the back definately looses it's power and grab (feel as well) after a run usually about the same time you notice issues. My bike with 8" in the back has no issues.

What's funny is a 180mm rotor is what, 7"? Avid does what, 160, 180, and 203? I can't exactly say if a 8" is better than a 7" but truthfully it's worth trying, especially if you're doing alot of DH runs on it the 8" in theory should work better.

 

[rigidhack]

Larger surface area = greater heat dissipation. Theoretically an 8" rotor will be better.

 

[DirtyMike]

I have eights front and rear, sma problem, need to smooth out the holes in the rotor, take a real fine round file and some time, also if you ca. find a bike shop that has a brakemount facer, not a common tool, but will give a more flush mount to the bike reducing vibration even more. Either way teh 8 inch rotor means beter braking, more heat dissipation, and longer pad life, would still get the eight reguardless of what you do to the brakes, but dont expect the noise to be gone just from that

 

[jvnixon]

you could also try a dot 5.1 bleed

 

[funkendrenchman]

Sorry to hijack, but how is the bike otherwise? I ordered the same one.

 

[denjen]

Sorry to hijack, but how is the bike otherwise? I ordered the same one.

Incredible. I have never owned a bike that just begged to go faster and faster. I was pedaling into sections that I usually just coasted into. I never felt out of control, the faster and harder you push it the better it works.
Couple things to look out for.
1- Take every nut and bolt off of the bike and grease it up. Not sure how long these bikes sat in a warehouse some where, but every thing was pretty dry.
2- Take the i-drive apart and pack it full of grease. It comes with a very light weight grease, put something heavier in there.
3- Take the bushing assembly on the chain guide apart and grease it up. There was no grease in mine at all when I got the bike and it actually locked the suspension up.
4- The arm that connects the frame to the chain guide needs some more spacers to tighten everything up. There is a little slop that allows the arm to bounce around and make a lot of noise when riding.
5- The inner bash ring on the chain guide needs to be spaced out slightly to keep the chain from coming off. I just put 2 small washers behind the bash guard at each bolt.
6- When you reinstall he chain guide after greasing every thing up, don’t over tighten it. You have to kind of play with it. If you over tighten it you with bind up the bushing assembly in the chain guide and cause a lot of stiction. If you under tighten it the chain guide will move around on the frame.

I know this sounds like a lot but if you just take the time as soon as you get the bike to give it some luvin you won’t regret it.

Let m know how you like it after you get some riding time in.

Dennis

 

[funkendrenchman]

That's some truly fine craftsmanship. How much of pain was it to take the I-drive apart?

 

[ragin-sagin]

Will getting the 8" rotor make that big of a difference in keeping things cooled down?

Thanks
Dennis

Yes
Your welcome
Sage

 

[ioscope]

Make sure you face the brake adapter, the bolts, and anything that connects the caliper to the fork. If there is a layer of paint in between, it will be a less reliable connection, and it will transfer less heat, leading to brake fade.

 

[denjen]

That's some truly fine craftsmanship. How much of pain was it to take the I-drive apart?

Its not that bad to take apart. You can do every thing I desribed in a couple hours if you know what you are doing. THe bike comes with all its manuals, just follow them. You will need a green Park pin spanner to take the i-drive apart.

 

[funkendrenchman]

Its not that bad to take apart. You can do every thing I desribed in a couple hours if you know what you are doing. THe bike comes with all its manuals, just follow them. You will need a green Park pin spanner to take the i-drive apart.

Hey, I've been working on the bike today. Is the chainguide bushing that needs to get greased the one with with a washer/nut and two teflon spacers? That appears to be the only thing called a bushing on the chainguide. Is that also the area that needs another spacer? The two teflon spacers don't appear to be enough. Did you get another teflon spacer?

If I am incorrect, could you be a little more specific?

 

[denjen]

Hey, I've been working on the bike today. Is the chainguide bushing that needs to get greased the one with with a washer/nut and two teflon spacers? That appears to be the only thing called a bushing on the chainguide. Is that also the area that needs another spacer? The two teflon spacers don't appear to be enough. Did you get another teflon spacer?

If I am incorrect, could you be a little more specific?

The bushings that need grease are in the middle of the chainguide. There is a big black washer kind of thing on the front and a silver washer on the back. If you take a small screw driver and pry off the black washer the sivler onr will come off also. the spacers are behind these. Clean and grease it good and put it back together. When you put it back together dont over tighten the BB on the drive side. If you do it will pinch the bushings in the chain guide and bind it up. What I did was get everything back together in the stand. Tighten the BB up just enough to hold it then take it out of the stand and push down on the back. Finish tightening the BB as you are playing with the suspension. If the chain guide is moving over the BB cup tighten just a little more. If the suspension dosent seem to be cycling freely loosen up just a bit. As for the other spacers I just went to a hardware store and found a simalar size and spaced it out.

Have you gotten much time on the bike yet? Ive gotten 5-6 days on mine and am loving it. Once I worked the kinks out it is the fastest bike Ive ever owned.

Dennis

 

[funkendrenchman]

Haven't ridden it yet... on day 2 of getting it ready.

Right now I can't loosen the drive side bottom bracket to get the guide off.

I know I need spacers for the inner bash guard, but where else exaclty did you use them?

 

[denjen]

Haven't ridden it yet... on day 2 of getting it ready.

Right now I can't loosen the drive side bottom bracket to get the guide off.

I know I need spacers for the inner bash guard, but where else exaclty did you use them?

Yeah the BB a bitch to get loose just takes some musle.

You are just going to have to play around with the spacers on the arm to get it right. This is my second Dhi I broke the first one a couple years ago. I still had the frame hanging in my garage so I just took the little arm off of the old one and it works great.

 

[Eren]

yea, my rear juicy 7 did that same thing, but it didnt squeal, it just made a reallll ****ty noise like there was mud going through the pads, so i popped them out and they were fine, so i cleaned my rotor with WD40. The noise is now completely gone. If you do this be sure to really ride on the street in front of your house so you can rid of that WD40 (of course wipe the rotor as well). because it really makes the braking ****ty until you get it all off the rotor. .

hope this helps for squealin. .

Eren

 

[denjen]

yea, my rear juicy 7 did that same thing, but it didnt squeal, it just made a reallll ****ty noise like there was mud going through the pads, so i popped them out and they were fine, so i cleaned my rotor with WD40. The noise is now completely gone. If you do this be sure to really ride on the street in front of your house so you can rid of that WD40 (of course wipe the rotor as well). because it really makes the braking ****ty until you get it all off the rotor. .

hope this helps for squealin. .

Eren

WD40?????????? Are you on crack?

 

[funkendrenchman]

Still haven't ridden it yet on the trail. I'm waiting to swap the spring tomorrow.

I greased up the bushings today. I talked to the GT mechanic and he said that most of their riders removed one or two of those white bushings from the chainguide assembly (the outer ones, not the one in the center). He also said that usually they would sand those down to eliminate tightness. I removed the inner white ring and greased the whole thing. The travel feels a lot smoother now.

 

[Bicyclist]

WD40?????????? Are you on crack?

The ONLY thing you wanna put on your rotor/pads is a solvent or volatile liquid like rubbing alchohol or Clean Streak. WD40 is a lube/solvent.

 

[DirtyMike]

Actually wd40 isnt not a very good Lubricant, it actually makes for a better cleaner than lube, doesnt suprize me that it helped get rid of brake noise, the WD40 properties would have cleaned teh pad/rotor really well, then once it heated would have acted like a Polishing compound almost to help better make the two surfaces.

Not recceomending to use it on your brakes, because of coarse your first few topps are not gonna happen till it heats up, but i can see why it would work. wd-40 is actually considered a solvent, and i use it as such in teh auto feild alot. As far as cleaning brake pads themselves Denatured alchohol has always worked best for me, cleans well, evaps fast. Oh yeah, Ever have a floating rotor stuck on a hub of a car, Douche it down with wd-40 and let it sit for about 5 minutes, then hit it with the Denatured alchohol. Old timer taught me that and explained why it works, i forgot exactly why, but i still do it, and Ill be damned it works everytime

 

[Bicyclist]

Huh, I've always been told WD40 is in between a lube and solvent. I guess not, it sounds like you know your stuff.

 

[DirtyMike]

Your right, its right inbetween, oil based solvent!!! Great stuff

 

[Robusto]

In order to clean my brakepads and my rotors on my Hayes 9s, I use some stuff called Berkebile Braklean (Brake-clean). My dad used to be an automotive mechanic, so we have a ton of it laying around. It works pretty good, but you have to get the brakes hot, and up until then you have ZERO braking power. Does work though..

 

[funkendrenchman]

Avid gave me some organic pads to try to get rid of the noise. We'll see how they work out. That is what they are stocking on their new Code brakes.

 

[denjen]

Avid gave me some organic pads to try to get rid of the noise. We'll see how they work out. That is what they are stocking on their new Code brakes.

Let me know how those work for you, My rear brake keeps glazing ove from the heat. I've tried sanding it down but it just glazes over agian.

 

[monke880]

I have juicy sevens with 8 inch rotors and i have never had a problem with them making noise.

 

[Chunky Munkey]

Just got a new bike. It came with Juicy 7's. Great brakes they have a great feel and a lot of power. Problem is the rear came with the 180mm rotor and I can feel the rear brake pumping up and starting to squeal about 3/4 of the way down every run. After it cools down it is fine but does it again on the next run. Will getting the 8" rotor make that big of a difference in keeping things cooled down?

Thanks
Dennis

A larger rotor without a doubt will cool better than a smaller. Also look at the Automotive angle. Large breaks on race cars are a must. So go larger. I suggest a 24 inch rotor on a 26 inch wheel.

All jokes aside, do they make ceramic pads for mountain bikes? I put them on my Corvette because I heard they were better than metallic and supposedly NASCAR uses them because they get grippy-er the hotter they get. I'm not sure though because I'm still on rubber breaks but don't want to spend the cash on disks if I'm considering buying a bike with them on already.

Anyone know if they make ceramic pads for mountainbikes?