drill pattern front duo disc roters

Im re ferbing a couple rotors from an ltd 900 and was wondering about the drill pattern would be the best for durability and stopping power

I prefer smaller 1/8" holes myself,get yourself a straightedge and a pencil and just start laying out different patterns till you find one you like.

HERE'S THE Z1R FACTORY PATTERN.
HELPS TO FIND SOMEONE WHO HAS ACCESS TO A CNC MACHINE, AND CAN KNOCK IT OFF AT LUNCH OR BREAK TIME.
I SURE MISS BEING RETIRED. I MISS THE PARTS ROOM AND MACHINE SHOP.

Here's a early KZ disk. They were on LTD,KZ and KZP's. I never understood the odd spacing. Once I wave them turned, they'll be on my bike.
Steve

swest wrote: I never understood the odd spacing.

I also noted the weird drill pattern, on many of the stock disks, a few decades back. I wonder if it's not a weight balance thing? ...but no way to confirm or deny.

swest wrote: I never understood the odd spacing.

I have a theory that it's to reduce the noise from the pads running over the drill holes. The Z1R rotors make very a noticeable "fizzzzzzzzz" sound when braking.

I was thinking that an irregular spacing between holes would spread the sound frequencies around and make the noise less noticeable. They do this with blower fan blades to make them less annoying, by making each blade a slightly different size and shape. The idea is that the overall sound level may be the same, but the noise is spread out over a range of frequencies instead of one single frequency, so it's less annoying. More like white noise as opposed to a single tone.

I have no idea if this is why Kawasaki used the odd spacing... it's just my crazy idea.

!Seymore wrote:

swest wrote: I never understood the odd spacing.

I also noted the weird drill pattern, on many of the stock disks, a few decades back. I wonder if it's not a weight balance thing? ...but no way to confirm or deny.

I've had them on twice. I thought about balance so I tried to off set them. The way they're drilled, it is impossible to get them 180% apart. It might have to do with harmonics. Maybe someone can find out.
Steve

I dropped by a friends today and brought my disks. He has a machine shop in his garage. I showed them to him so he put one on the lathe and checked it out. Seems the disks have high spots sure but the problem was the hubs. They were out .004-.010 due to some type of shock. It's funny I didn't notice it when I put a clamp on a fork to measure the run out but there it was. He turned them and I installed them. The high spots are nearly non existent. I'll try some emery cloth on a block to see if I can smooth them out while spinning the rim. As it is now, I can hardly feel anything on my lever. We'll see.