Rotor conversion question
- SWest
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- 10 22 2014
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Re: Rotor conversion question
28 Nov 2014 08:39steell wrote: If you are trying to loosen a tight bolt, do you use a 4" long wrench, or the 2' one?
It's all about leverage, the further away from the axle a caliper is, the more leverage it has against the rotating tire/wheel assembly, the easier it is to stop. The bigger the rotor diameter the better the brakes. Buell takes it to the logical maximum with it's peripheral brake rotor and small caliper mounted on the inside of the rotor.
Single disk KZ models use a thick disk, dual disk models use two thin disks. If you use two thick single disk rotors in a dual configeration, you will notice the difference. It takes longer to stop.
Two 1980 KZ1000 drilled dual disk rotors and a pair of 83-85 GPz750 calipers on the front of my 79 KZ750 twin. It stops so hard I wonder if the handlebars are going to bend forward or the rear wheel come off the ground. :laugh:
That's a good way to shear bolts.
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
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- floivanus
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Re: Rotor conversion question
02 Dec 2014 11:03
Yeah, with the stick ltd rotors fitting the calipers without a giant ugly conversion bracket was a giant pain in the ass; the katana rotors would have required a big ole ugly bracket; no dice, gave the front end to the guy who bought my 78 A2 (he had a katana on the trailer as well, so what the hey?)
As it is, I had to weld shut the top mount hole, jig it up and drill/tap then saw out a bracketfor the lower mount and weld it up, took three passes(one on front and two on the back to get full penetration on the 1/4" bracket with the MIG but it should work, got both sides done now.
New grade 8 hardware, and as you can see the caliper JUST clears the top mount lug, crappy pics I know.
As it is, I had to weld shut the top mount hole, jig it up and drill/tap then saw out a bracketfor the lower mount and weld it up, took three passes(one on front and two on the back to get full penetration on the 1/4" bracket with the MIG but it should work, got both sides done now.
Attachment image_2014-12-02.jpg not found
Attachment image_2014-12-02-2.jpg not found
New grade 8 hardware, and as you can see the caliper JUST clears the top mount lug, crappy pics I know.
my bikes; 80kz1000(project), 77 gl1000, 74 h2 (project)
Past; 78 kz1000, 83 kz550
Andrew
Past; 78 kz1000, 83 kz550
Andrew
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- PLUMMEN
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Re: Rotor conversion question
02 Dec 2014 11:18How much room on the inside between calipers and rim?floivanus wrote: Yeah, with the stick ltd rotors fitting the calipers without a giant ugly conversion bracket was a giant pain in the ass; the katana rotors would have required a big ole ugly bracket; no dice, gave the front end to the guy who bought my 78 A2 (he had a katana on the trailer as well, so what the hey?)
As it is, I had to weld shut the top mount hole, jig it up and drill/tap then saw out a bracketfor the lower mount and weld it up, took three passes(one on front and two on the back to get full penetration on the 1/4" bracket with the MIG but it should work, got both sides done now.
Attachment image_2014-12-02.jpg not found
Attachment image_2014-12-02-2.jpg not found
New grade 8 hardware, and as you can see the caliper JUST clears the top mount lug, crappy pics I know.
Still recovering,some days are better than others.
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- floivanus
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Re: Rotor conversion question
02 Dec 2014 11:34
It's just a two piston caliper, should be enough room when i switch to spokes, I've got a half inch with the ltd wheels. These are lighter than the stockers with a little more piston area. Should be a big improvement with the new master and stainless lines. I believe I am just leaving the stock rotors alone. To get these lightened by windowing them it would be $100 a rotor for a 2lb total weight savings.
my bikes; 80kz1000(project), 77 gl1000, 74 h2 (project)
Past; 78 kz1000, 83 kz550
Andrew
Past; 78 kz1000, 83 kz550
Andrew
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- PLUMMEN
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Re: Rotor conversion question
02 Dec 2014 11:46
Id get a set of undrilled rotors and have your own pattern drilled in them,then have them surfaced to the specs for dual discs.
They'll be much lighter that way.
They'll be much lighter that way.

Still recovering,some days are better than others.
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- floivanus
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Re: Rotor conversion question
02 Dec 2014 11:53
I've got a set of undrilled but I'm sitting on them for right now, don't feel like spending on machining costs; might as well buy a mini mill and do it at shop rate costs. I've still gotta get the shock mounts welded in my swingarm and I just ordered shocks and a gasket set, etc. and I gotta cover the seat and did I mention I wanna finish my 75 wing?
Then the H2?
Then the 76 ltd?
Then my wife's 80 ltd.
Then the 67 barracuda.
I think I have a problem here.
Then the H2?
Then the 76 ltd?
Then my wife's 80 ltd.
Then the 67 barracuda.
I think I have a problem here.
my bikes; 80kz1000(project), 77 gl1000, 74 h2 (project)
Past; 78 kz1000, 83 kz550
Andrew
Past; 78 kz1000, 83 kz550
Andrew
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- PLUMMEN
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Re: Rotor conversion question
02 Dec 2014 16:04
You can have them surfaced by any shop that surfaces flywheels,usually $10-15 each.
As far as drilling them Ive always just used a drill press to do them.
As far as drilling them Ive always just used a drill press to do them.

Still recovering,some days are better than others.
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- SWest
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Re: Rotor conversion question
03 Dec 2014 05:13floivanus wrote: It's just a two piston caliper, should be enough room when i switch to spokes, I've got a half inch with the ltd wheels. These are lighter than the stockers with a little more piston area. Should be a big improvement with the new master and stainless lines. I believe I am just leaving the stock rotors alone. To get these lightened by windowing them it would be $100 a rotor for a 2lb total weight savings.[/quote
Why go to wire wheels? 1/2" should be enough clearance. I miss my Lester Mags. I like the look of the drilled rotors but that can be done any time.
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
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