Author Topic: Rotors  (Read 1272 times)

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Offline GIant81

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Rotors
« on: March 20, 2018, 01:41:09 am »
I've done some reading because I'm getting rotor pulse.

New pads didn't fix it, and I think I may have bent one of my rotors while I was changing my tire.  I will be trying to free up the buttons, and making sure I've given it a thorough scrub down to eliminate the varnish I hear can get stuck to the rotors and cause a pulse.  Worst case, if I need new rotors, how bad are these?  http://r.ebay.com/B6v6lH. I'm only looking at needing them until next spring when I can get myself a nice new set of OEMs with tax money, but I just don't have the money for a full set of OEM/EDC/name brand/whatever made of gold/whizzbang whatever some MotoGP racer uses/ rotors right now. 

It's not a race bike, it's a commuter, so I'm hoping someone has used these or something similar and they will work for the interim until I get some cash. 

Would I be better off with a pair of used rotors?  I saw a couple ads for used OEM rotors, they gave thickness measurements and they appeared fine, but no mention of runout.

Thanks!

Offline C. Moore

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Re: Rotors
« Reply #1 on: March 20, 2018, 09:58:16 am »
That's a good idea to try and free up the buttons first.  I've read some positive things about the cheap rotors from China but I have no personal experience. I've purchased a used rear rotor on ebay with success but not the fronts. The up fronts are too critical for me to go used there.
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Online Roger B

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Re: Rotors
« Reply #2 on: March 20, 2018, 11:46:17 am »
I bought some used rotors on ebay off of a late model zx14r...same rotors, trying to get lower mileage usage.  A pair of used rotors are still $100 + .

Offline Mikes14

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Re: Rotors
« Reply #3 on: March 21, 2018, 09:54:59 pm »
I've done some reading because I'm getting rotor pulse.

New pads didn't fix it, and I think I may have bent one of my rotors while I was changing my tire.  I will be trying to free up the buttons, and making sure I've given it a thorough scrub down to eliminate the varnish I hear can get stuck to the rotors and cause a pulse.  Worst case, if I need new rotors, how bad are these?  http://r.ebay.com/B6v6lH. I'm only looking at needing them until next spring when I can get myself a nice new set of OEMs with tax money, but I just don't have the money for a full set of OEM/EDC/name brand/whatever made of gold/whizzbang whatever some MotoGP racer uses/ rotors right now. 

It's not a race bike, it's a commuter, so I'm hoping someone has used these or something similar and they will work for the interim until I get some cash. 

Would I be better off with a pair of used rotors?  I saw a couple ads for used OEM rotors, they gave thickness measurements and they appeared fine, but no mention of runout.

Thanks!


The link didn't work for me, but I have the Chinese rotors off of Ebay and they are fine. I put them on a couple of years ago. Before buying them I tried everything with the oem rotors that you would read here, but still had the pulsing. Put on the Chinese Ebay rotors and still had the problem. Turns out that the front fork adjustments/suspension setting were not the same. In fact the one adjustment was all the way down and the other all the way up. It must have been from the previous owner. After adjusting them equally the pulsing went away so not sure I ever needed the new rotors but glad that I bought them since the bike had 40,000 miles.

Offline MAN OF BLUES

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Re: Rotors
« Reply #4 on: March 21, 2018, 10:14:04 pm »
i've probably bought 10 sets of various used rotors in the last 15 years, off ebay... ( mind you none for the C14 tho ) out of that, I think I may have gotten 3 actually usable discs... so, if you ask yourself the question "why are they being sold on ebay" the answer is pretty clear... either they are off a parted out, wrecked bike, or a parted out non functioning bike, or simply the cast offs from someone recouping the cost they spent for upgrading their bike to better brakes.. because they had an issue..

Doesn't take much to hose up a rotor.. simply letting a tire fall over during a tire change, or rough handling, will ruin one.

Whatever you buy, by new ones, from a reliable source,nthat you can recoup your expense back from if they are substandard...
That being said, I'm still running my as delivered OEM's on my '08.

But the Chinese ones seem to be ok so far, as I can see, having rudden a couple peoples bikes that were wearing them.

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Offline RoadKillHeaven

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Re: Rotors
« Reply #5 on: March 23, 2018, 03:39:33 am »
My 16 has developed brake judder, much like you describe.
I've scheduled an appt to dealer (mine is under warranty) to see what they say.
I am planning to make full-floating set-up. Not a real full-float as race bike have. I plan to re-use spring washers with new buttons that use E-clips rather than rivets. 
The buttons have springs (wavy washer) on the backside of the button. It is virtually impossible to "free up" C14 buttons with common methods people use. I've tried "cleaning" buttons with WD40, cutting oil, Purple Clean. Nothing "frees up" those buttons. It feels like you've "freed up" some buttons because riveting is not 100% uniform and some rivets aren't squeezing  spring washer as much as others. Also, aluminium hub that rotor is attached to via buttons succumbs to material removal on the backside by performing "clean up" procedure. My previous bike had brake rotor buttons I could spin with my fingers. Not this one though.
EBC set-up is in my radar. Just have to see what the dealer says. 

Offline Deepsea

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Re: Rotors
« Reply #6 on: March 23, 2018, 06:02:20 am »
"I am planning to make full-floating set-up. Not a real full-float as race bike have."

Please explain to me the difference between "Full-floating" and "Not a real full-float as race bike have"
IMHO it's either non float (ridged or one piece disc), semi float (spring washer behind buttons) or full float (no spring washer). I've never heard of a not full float full floating disc.
  It is possible to remove the spring washers from stock disc's using a Dremel type tool if being very careful not to damage the aluminum carrier.
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Offline ZXtasy

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Re: Rotors
« Reply #7 on: March 23, 2018, 09:44:37 pm »
There is a custom bike place, Florida I think Roaring Toyz. Tons of posers have them take the brand new discs off of bikes like ZX-14's to either showcase the 21 inch chrome rim or replace them with ridiculous lazer cut units. Anyway, they sell the new stock rotors really cheap, or did for me. Nice folks.
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Offline RoadKillHeaven

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Re: Rotors
« Reply #8 on: March 24, 2018, 06:06:32 am »
"I am planning to make full-floating set-up. Not a real full-float as race bike have."

Please explain to me the difference between "Full-floating" and "Not a real full-float as race bike have"
IMHO it's either non float (ridged or one piece disc), semi float (spring washer behind buttons) or full float (no spring washer). I've never heard of a not full float full floating disc.
  It is possible to remove the spring washers from stock disc's using a Dremel type tool if being very careful not to damage the aluminum carrier.
This is going to be my "special" project. I am going to modify OE brake rotor to utilize new buttons with "stock" spring washers to make pseudo full-floating rotor.
Perhaps my automotive jargon is not up to "common" standards. But rest assure I have some, humble that is, knowledge and experience in automotive engineering.
Since no one has performed such modification on C14, I'll attempt it. If I succeed, I'll report on my final thoughts.
Cheers...

Offline Deepsea

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Re: Rotors
« Reply #9 on: March 24, 2018, 06:34:54 am »
If I understand correctly your going to remove the buttons and replace then with  slightly longer ones? Thus creating less spring pressure. If that is your intent please do keep us informed. I've considered this in the past but never really saw the need/benefit as being great enough. Do you plan on making your own buttons?
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Offline RoadKillHeaven

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Re: Rotors
« Reply #10 on: March 24, 2018, 07:01:02 am »
Yes. It looks like C14 requires 5mm buttons.
In my estimation, new (longer) buttons will create "slack" in the rotor which will be off-set by "stoc" spring washer. This should create less tension in the joint, making brake rotor outter ring less bound up compaerd to OE which is "almost" like one piece rotor. I've never experienced such a "tight" brake rotor on any of my bikes.
My DH Bronson has full-floating front brake rotor and I can spin buttons with my fingers.. ;)

Offline TimR

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Re: Rotors
« Reply #11 on: March 24, 2018, 08:17:06 pm »
I have a 09 with the original rotors and 50K on the bike. I found if I get brake pulse or vibrations when stopping I need to clean the rotors. I use a medium sanding pad and lightly sand/clean both sides both rotors the best I can. I say lightly sand because I'm not wanting  to remove medal from the rotor but merely cleaning off pad material. My theory is when the disks are hot and you use the front brake to keep the bike from rolling the heat causes pad material to stick. Now that I have EBC pads the problem is not nearly as noticeable. Anther thing I would do to clear the caked on pad material is brake hard and steady from a high speed (not supersonic buy say 60-70) and release just before coming to a complete stop. This too would reduce the pulse/vibrations for awhile or until I stopped and used the front brake to hold the bike after running down the road awhile. I've not messed with the 'buttons". YMMV  Tim
« Last Edit: March 24, 2018, 08:20:30 pm by TimR »
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Offline RoadKillHeaven

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Re: Rotors
« Reply #12 on: March 29, 2018, 12:18:43 am »
I've dropped off my bike at the dealer. While I was there, talking to manager, we've checked ZX14 and ZX10. It is strange, both bikes have free-spinning buttons. Then we've checked C14 and other, including MV Augusta. I couldn't spin buttons by hand. Then I spoke with the master tech and he said C14 uses what is called "static" brake rotor. The tech wasn't able to replicate the judder I am complaining about. They are going to keep my Connie for couple of days to see if they can replicate the brake shimmy. As far as runout goes, tech I spoke with said it was within specs.
We shall see...

Cheers... 
 

Offline MAN OF BLUES

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Re: Rotors
« Reply #13 on: March 29, 2018, 09:58:06 pm »
I've dropped off my bike at the dealer. While I was there, talking to manager, we've checked ZX14 and ZX10. It is strange, both bikes have free-spinning buttons. Then we've checked C14 and other, including MV Augusta. I couldn't spin buttons by hand. Then I spoke with the master tech and he said C14 uses what is called "static" brake rotor. The tech wasn't able to replicate the judder I am complaining about. They are going to keep my Connie for couple of days to see if they can replicate the brake shimmy. As far as runout goes, tech I spoke with said it was within specs.
We shall see...

Cheers...

 :)) :)) :)) :)) :)) :-\ :-[ :-[ ::) ::) ::) :truce:

Now THAT is a hoot... your eggspurt tech is an idiot...
Look into the microfiche, on kaws website, and compare the part numbers on both the ZG1400 and the ZX14 Ninja zx20R...
And see the rotors... they are the exact same parts...

41080-0570-5C

Or, if you installed Ohlins forks, which are golden colored...
You could use p/n 41080-0570-488... same rotor, seame construction, gold painted center hub...



Soooooooo....... you trust your tech guy now?   :41: :41: :85: :41: :57: :72: O:-) :s_laugh: :hum:

Static rotors....  :rotflmao: :rotflmao: :rotflmao:
« Last Edit: March 29, 2018, 10:09:03 pm by MAN OF BLUES »

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Offline Deepsea

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Re: Rotors
« Reply #14 on: March 30, 2018, 02:44:52 am »
Static vs Dynamic? I guess the static rotors only work if the bike is being ridden in the static (center stand down) mode and the ZX when dynamic (center stand up). Interesting!! :-\


 :friends: :confuse: :hum:




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Offline MAN OF BLUES

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Re: Rotors
« Reply #15 on: March 30, 2018, 08:05:08 pm »
Static vs Dynamic? I guess the static rotors only work if the bike is being ridden in the static (center stand down) mode and the ZX when dynamic (center stand up). Interesting!! :-\


 :friends: :confuse: :hum:

 :rotflmao: :rotflmao: :rotflmao: :great: :great:

I do have to admit, there are actually some "high end" aftermarket rotors, which contain spools/bobbins that are polygonic shaped, as opposed to cylendrical or round shaped, and those specific rotors spools/bobbins do not rotate...  this came about in a discussion over a year ago, and I can't remember exactly what manufacturers were included, but in general, unless they use this as a selling point, you would never really know the spool shape.
I think it may have been Ducati bobbins in the conversation, they had a sort of flatted sides on cylendrical bobbin, or an "H" shape, and also a style of EBC may have been the ones with a square shaped bobbin.
https://ebcbrakes.com/articles/sd-system-square-drive-and-how-it-works/

I had a set of "ultralite" EBC's on my old C10, that I think were the SD style... but no longer have that bike... it did have superb brakes when I installed them... high priced, but superb.

Read this closely... all the words...  :beerchug: :great:
https://ebcbrakes.com/product/floating-mc-rotors/

Should splain it well...  and not being able to move the bobbins by hand is a GOOD thing...
 ;)
« Last Edit: March 30, 2018, 08:41:06 pm by MAN OF BLUES »

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Offline gpd323

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Re: Rotors
« Reply #16 on: March 30, 2018, 10:08:34 pm »
My many Kawasaki's have never had free spinning rotor buttons. I have however replaced the front rotors with Brake-Tech axis SS rotors. These are true free floating rotors. I have over 100K on sets and have had zero issues, no judder, no weird braking and minimal noise. The rotor does have a slight side to side free play and at very low speeds hitting a sharp bump makes the rotor rattle. But besides that They are an excellent option. Costly though. I have the oversize 330mm on my C14.

I would be very careful replacing the stock rotor buttons with a looser version. I am not sure but I would be concerned that the rotor and hub (loose buttons) could separate under hard braking. The stock OEM rotor buttons are captured on the hub, removing this capture may not be a good idea.
Greg Downing
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Ride while you can.

Offline RoadKillHeaven

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Re: Rotors
« Reply #17 on: March 31, 2018, 06:36:32 am »
According to Kawasaki, .005" runout doesn't warrant rotor replacement. It is weird because ~ .005" runout on a fixed rotor (automotive) will produce brake shimmy which will warrant resurfacing  or replacement of brake rotors.
Since Kawi will do square root of jacksh..t  to help me, I will replace them myself.
I can't spend $600 on EBC or similar setups @ this moment.
Are there alternatives?
P.S Once I get replacement, I will start my "project" to see what is and isn't possible with OE rotors.


Cheers...

« Last Edit: March 31, 2018, 06:40:27 am by RoadKillHeaven »

Offline GIant81

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Re: Rotors
« Reply #18 on: April 06, 2018, 01:02:23 pm »
Are there reasonably priced full floating setups for the ZX14r/ZG1400? 

and by reasonably priced I'm hoping for not much more than OEM rotor price. If it's going to be like 2x OEM price because it's 'racing' level then I'm out. 

Offline NYbiomed

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Re: Rotors
« Reply #19 on: April 06, 2018, 06:45:07 pm »
The Chinese rotors from Ebay are pretty good, BUT...you will have to shim the ABS sensor with a washer or two, as the hub thickness is a bit thicker than OEM and will hitt he sensor and create moderate pulsation not exactly fixing your problem. I have been using them for the last 5k miles and seem pretty good. I'm happy with them and would purchase again, IIRC, they run about $180.00/set.....

I think they are these:

https://www.ebay.com/itm/Front-Brake-Disc-Rotors-For-KAWASAKI-Ninja-ZX6R-636-2013-2017-ZX10R-ZX14R-08-17/183117050876?hash=item2aa2a073fc:g:NRMAAOSwsFVaogL9&vxp=mtr
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Offline GIant81

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Re: Rotors
« Reply #20 on: April 06, 2018, 07:30:00 pm »
I put an offer in on a pair of these

http://r.ebay.com/wzwMnO

I figured they looked the closest to stock. 

Offline JDSCO

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Re: Rotors
« Reply #21 on: April 06, 2018, 09:00:17 pm »
I always use EBC pads for OEM replacement but have never replaced rotors
I've never encountered these "shimmy" problems with my Kaw's
but I'm not a motoGP guy like you guys are
I do "exercize" the buttons on the '08 and my '16
They don't freely rotate but do rotate with minimal torque

This is going to be my "special" project. I am going to modify OE brake rotor to utilize new buttons with "stock" spring washers to make pseudo full-floating rotor.

 
If I understand correctly your going to remove the buttons and replace then with  slightly longer ones? Thus creating less spring pressure. If that is your intent please do keep us informed. I've considered this in the past but never really saw the need/benefit as being great enough. Do you plan on making your own buttons?
Yes. I'm very interested in seeing how you do that!

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Offline MAN OF BLUES

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Re: Rotors
« Reply #22 on: April 06, 2018, 09:31:04 pm »

30 YEARS OF KAW.....Rich R. (the other one..)  COG 5977  JUSTAMEMBAHNOW

Offline GIant81

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Re: Rotors
« Reply #23 on: April 06, 2018, 10:43:12 pm »
I always use EBC pads for OEM replacement but have never replaced rotors
I've never encountered these "shimmy" problems with my Kaw's
but I'm not a motoGP guy like you guys are
[...]

I don't run even close to MotoGP but I'm pretty sure I bent it while doing my own tire change.  The one rotor is so out of true enough that I can visibly see the wobble with my naked eye when I spin the front wheel.

Offline RoadKillHeaven

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Re: Rotors
« Reply #24 on: April 07, 2018, 04:17:22 am »
Google is your friend...

http://thediscdoctor.co.uk/Bobbins.htm

Postage state side is ridonkulous , otherwise I'd be getting fancy with bobbins...