Z1 OEM dual discs

Hey folks,

Did the dealer installed dual front disc option on Z1 (and Z1A and Z1B) have the thick rotors? I just took the calipers to my "thick" single disc rotor and mic'ed it at 0.28" (~7mm). All of the Z1 6-bolt rotors I ave are the same thickness and I know on later KZ1000s with dual discs, the disc thickness is much thinner.

Also, what did the dealer option call for in a master cylinder? Did they bore the 1/2" single disc MC out to 5/8"? Did they have a different MC for the dual disc kit?

Thanks!
Mark

AS far as I know...and it may be wrong. The dual disc option had the same "thick" disc, it was all they had then in the way of genuine parts at the time.
I'm sure there was a genuine 5/8 MC to go with them.

the kit contained the second disk, the right handed caliper, the pipe, hose and replacement splitter, plus the 5/8" master cylinder.

So while we are on this topic. Why are the dual disc calipers behind the forks vs. the single disc caliper is in front of the forks?

kaw-a-holic wrote: So while we are on this topic. Why are the dual disc calipers behind the forks vs. the single disc caliper is in front of the forks?

They're not.

Most people flipped the front forks around. Look for the little fender mount tab.

kaw-a-holic wrote: So while we are on this topic. Why are the dual disc calipers behind the forks vs. the single disc caliper is in front of the forks?

Because ma kaw realized they looked better starting on the 76 900ltd! :woohoo:

because some bikes tended to handle bad with the calipers hung out there instead of inside ...

trianglelaguna wrote: because some bikes tended to handle bad with the calipers hung out there instead of inside ...

A likely excuse. lol

Read a great article on this subject just recently where they compared brakes on a Z to brakes on a Ducati back in the 70's. Can't find it here at work. They found that the brakes out front of the fork leg made for poor handling because of their mass location in relation to the rake angle. That's fairly intuitive but they did the experiments to prove it. The bikes were fairly evenly matched (believe it or not!) when the fork legs were turned around so the Z calipers were behind the legs.
As to why they put the calipers out front, there was no real reason given, they figured the Japanese just thought it looked better. Some discussions I've had with guys who were active in racing back then raised a few theories. The calipers stayed cooler, there was less chance of interference with other parts of the bike (?) they were easier to get to, it showed off the new, simple designed calipers to poke the finger at HD, and finally, they didn't think it would matter.

Gentleman's Express: Some good reading about the reason we do some of the mods that we do...

All the Z1, (K)Z900 & Z1000A1 models wether single or dual disc had front mounted calipers fron the factory. The first model to have the rear mounted calipers was the Z1000A2.
Also some people like to retain the 1/2" master cylinder when doing a twin disc conversion. Although it means you have to pull the lever in futher they say it give you more "feel". Don't know if I am convinced though.

Using a 1/2" bore master cylinder on a dual front disc setup is NOT safe. The 1/2" piston doesn't push enough fluid through the system.

I'm curious as to how Kawasaki fixed this problem. Did they ship out a new 5/8" bore MC?