Hi All,

Just picked up a set of second hand 07 OEM front and rear brake disks for $80.00AU.
I did this as I have a very slight pulse on my front brakes due to possible warping and as the guy accepted my offer I thought why not as a possible resolution?
He is going to use his 07 ZX-14 as a street AND track bike and bought new after market disks and carbon rims to save around 30kgs of weight.
Although they look great with minimal use to the eye, there is of course every chance there is an issue with them such as warping.
Unfortunately I don't know history or kms of the bike they came off as I foolishly didn't ask.
I know I know, not the smartest move I have ever made but if there is an issue its not the end of the world as it was only $80.00.
The guy did seem decent, genuine and knowledgeable about 14's so I'm kind of confident all is cool.

Is there any way I can check if they are good without taking to the Kawasaki guys?

1. What you need is a dial indicator. Very hard to find a place to set the needle with all the air holes.
2. I find the front fork jack that goes under the forks, holds steady the front end. Here's the problem.
3. I'm going to use a pencil with sharp point. Use a coat hanger. Use some pointed object as the indicator.
4. I have to have my front forks not move at all. I have the point at the outer edge of the first disc.
5. My pulse is one disc lets say. Lets say we park the other used one and find the one on the bike first.
6. The speeding wheel and a moving fork is to abort that move as you'll see and the more you bring the point closer is to see one warp and the other straight... OR...
7... I'm going to place a tiny screwdriver under a pad and run it back so I can place one business card under that pad.
8. I am going to move to the other side of that same caliper, wedge my driver under and back that pad so I place the next card under that pad.
9. I now grab the brakes and bite down on the lever. I release and pull the cards out of the caliper.
10. I spin the wheel and is there a sheee-sheee-sheee is warped.
11. I place the business cars on the other caliper, hit the brakes, pull the cards, spin the wheel I hear jack shit.
12. I found the warp via some business cards or pointer with wheel still on bike.
13. Park the other disc for the next warp.

_________________________________________________________________________________________
Why did my disc warp?

1. I haven't changed oil in the brake system and it's every 2 years times my year of bike is when?
2. I have this boil occur and in that bubble is h20/oxygen/vapor/is heavier than oil.
3. I now settle under the square quad-ring and displace the oil, for I am water now at the lowest point.
4. I crystallize and raise the rubber ring against the piston.
5. I should have returned into that square round cut in the caliper as I squish oil out of that groove.
6. I have memory and when you release the lever, I relax, reenter that machined square, push the oil out, pull the piston back.
7. I should not be dragging on the discs when I am released. The pads dangle free and the piston is not that far back you pull the lever and it's instant, correct?
8. I now press on the front lever and feel if my discs feel free or they sort of drag [do it now].
9. I drag, I cannot pull away from the pad. Wherever that piston stopped is where it is and cannot move back.
10. I therefore heat the disc all the time I am rolling. I may need to rebuild my calipers if the flush does not release my discs or here we go is ruin the good used one(s).

Wheel axle sprocket and brake disk inspection

You can use the bike and axle instead of a wheel stand..but if you got that far, might as well just ride the bike to see if the rotors feel warped. The dial gauge will help confirm the rotor is warped and pinpoint which of the rotors is warped and how much.

Sorry guys.
Should have mentioned that my original brake disks are still on front and back as the pulse is minimal at this stage but wanted to know if there was a way to check the ones I just bought that are not installed.

The ZX-14 (as well as C14 which are the same) front brake rotors have a tendency to warp. I'm sure hub's explanation covers some but others seem to warp spontaneously. But the best way to check for warping is with a dial-indicator. These are inexpensive. One method is to just raise up the front wheel on a stand and test it. Use the steering lock if your front stand allows the forks to turn while raised.

The Service Manual has the maximum runout allowable. If you're within that, the pulsating is not from rotor warping.

My ZX-14 front brakes are smooth but I also have a C14 and the front brakes "shudder" when braking hard at high speed, say about 60 mph of so. I checked them for runout and they are fine. I also checked for varying thickness and they are within spec. If you look at them carefully there is an area the size of the brake pads that is slightly discolored and I suspect that there is some corrosion or something caused by long-term contact with the pads. I bought my C14 used and the PO had left it sitting for 18 months without moving.

A worn front tire will act the warped disc: once you grab the brake and can tell the difference. Low speed lever pulse is going to show if the disc is the problem or if there is no pulse, the tire is next. How old/miles on the tire?

Tyres are Michelin Pilot Power 3 and around 6-7kms.
Front is still okay but rear is gone and is to be replaced.