brakes and disk fix

Robert, typically motorcycle brake rotors can not be Resurfaced or "Turned" because of they are relatively thin to begin with for rotating weight savings and also because most are cross-drilled, slotted, or some crazy shape (wave) for gas venting in high heat, (high performance braking) which makes them impossible to cut with a lathe without destroying the rotor and tooling when the cutting edge hits a hole.

Of course any dealer or serious racer would tell you to replace the rotor if it is scared deep enough to catch your fingernail. Re using them probably wouldn't cause any problems if they are not warped do to overheating but the brake performance will not be quite as good. You would know if the rotors are warped because you would feel pulsating in the lever & braking.

Rear rotors are fairly inexpensive (less than $100) compared to front rotors (usually $600-$800 a pair) because they are smaller and don't require the self-centering "buttons" to align them with the fork mounted calipers.

You are right to be skeptical of inexpensive off brand braking components because you have no way of knowing if the metal quality and manufacturing processes are up to spec. Stainless steel Rotors need to be heat treated and stress relieved to stabilize them and prevent them from warping from the heat cycles of everyday use & do to stresses within the metal during the mfg process. If this step was skipped on the cheap ebay rotors they wont last very long. (Common Problem)

When choosing a new brake rotor try to stay with the OEM manufacturer or a known quality aftermarket manufacturer like, Brembo, EBC, Galfer, or at least something recommended by a reputable shop.


Things to keep in mind when changing brake rotors:

Always Hone the surface of used rotors if you are changing to a different brake pads. Brake pads embed material into the rotor which is actually what creates the high level of friction that is required in high performance breaking. You can pick up a small ball hone that chucks into a drill from any auto parts store for under $10

Always use new rotor bolts / screws anytime you have to loosen or remove them. They are made of a special torque to yield metal and will be much weaker if reused.
These have to be purchased from the dealer but are usally under $20 for a set. Always torque them to the factory specs using a torque wrench.

Always Align your Rotors & Calipers. When installing your rotor finger tighten the screws first and then spin the wheel with rotor attached to self center it in the caliper before tightening it down to keep it from dragging on the caliper. Do the same thing whenever installing the caliper. install hand tight, spin the wheel, activate brake, repeat a couple times, then torque down you caliper to spec. 

www.ebay.com/itm/03-05-YAMAHA-R6-600-REAR-BRAKE-ROTOR-DISC-YZFR6-YZF-2003-2005-2006-2009-good-str-/330895521959

here is what I think im going to get to replace it with.

"this rotor is in GOOD CONDITION with normal wear from use. There is still plenty of life left on this part, and it is ready to install. We check our all rotors with a runout gauge and guarantee them to be straight!"

The company is called simpson cycles. And they are a junk yard essentially. This part was taken from a bike that could have been totalled for any number of reasons. I think the rotor should be fine.



what are your thoughts?

SWEET! Im ordering the disk right now.

Disintegrated was probably a bad word for it. I just feel like they disappeared in a very short time. 



Question about the hone. The only hone I am familiar with is a cylinder hone for making crosses the rings will seal against. What type of hone do you mean for the disks? Are you talking about a flat sharpening stone, like used to sharpen a pocket knife?

Ive ordered the brakes and new rotor, so I should have the project underway by wednesday or thursday. Ill pick up a hone in the meantime. thanks for your help, man.

Morgan, you are too helpful!

I've changed my fluid 2 times since owning the bike for a year. And I will probably do it again when changing the brakes. I've always done it the manual way (hose and bottle). And growing up and changing/bleeding fluid on cars on a normal basis, the bike is a snap! You don't need someone to sit in the car and press on the pedal. Thats one thing I love about my bike, or bikes in general, they are so easy to work on. I can work on it out of my apartment, ya know. The one thing I did not do, that you are suggesting, is use motorcycle brake fluid. I've been using car fluid (from autozone), and had no problems. I also asked the r6 forum guys and they said it won't be a problem. If I start doing track days I will definitely get some motorcycle fluid, though. I have been starting at the closest bleeder though. You are saying start at the furthest away?
I also heed your warning about overfilling. The first time I changed my fluid I did not do leave any air in it. Then I later found out my brakes could "lock up." I was thinking SHIT , and I changed the fluid the next day. I can't imagine the wheels locking up, that sounds like an absolute nightmare.


Another thing I do not think I will do, that you suggest, is get new bolts for the disk to the wheel. I know what you are saying about them being torqued and the threads stretching and loosing some of their strength. I remember this discussion when building engines too. People would always say to change out your ARP bolts and what not. I may end up doing it....I'm just thinking about it still. I will definitely use some lock-tite. I don't think my bike has been abused in the sense of pushing it to its limits on the track say. I mean, these bolts must be automotive grade, which is stronger than stainless and grade 8...So they should last a long time. I would reuse automotive grade bolts on my mustang all the time, and those bolts were from a car anywhere is the timeframe of 1964-1969, and I never had any issue with bolts breaking off, striping, etc. 

Im definitely getting that honing tool, thanks for the picture! That looks like it will come in handy in the future.

I was just watching a video and noticed something I did not know, though. Maybe you have some input. These circle looking things, "bobbins," are supposed to spin freely? Thats what this guys says in the video. And he says if they don't, you could warp your disks. It has something to do with the flex and heat dissipation between the disk and the bolt piece that brackets to the wheel hub. Thoughts? Should I oil them, like with chain lube, and make sure they are not frozen?

Update:

I got the rear rotor and pads on. They seem to be working great. I did my best to break them in with city riding, but inevitably made it to the highway before the 250 mile bedding period. I hear what you are saying about the buttons, I will definitely not lube them up. whats the progress on your engine, or is there a thread on here about it? Would love to know how its been tearing into that thing.

The play the rotors have are for self alignment during braking. They are also o called floating rotors for that reason. The calipers should not have any play in them, only the rotors.