320mm oversized rotors

ELCouz
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Re: 320mm oversized rotors

14 May 2010 16:01

EBC guy told me that a Vulcain 1500 98-03 REAR disc are 320mm and bolt-on on the GPZ750 82. BUT the disc thickness is 7mm they need to grind down to 5mm. These rear disc are overkill omg for a real wheel!

I don't have any reply from the guy since 2 days hope he still want to do them!

Regards,
Laurent

1982 KZ810-R1 GPZ with hindle 4-into-1 pipe

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PLUMMEN
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Re: 320mm oversized rotors

14 May 2010 17:48 - 14 May 2010 17:49

#367980

The Fish wrote:

JMO,
If you are custom making a hub, you can have it made to work with any brake disc you want.

Another JMO,
If you are making a hub, I can't see the advantage of making a (dimensionally) identical hub to one that is already offered (stock KZ). Custom make a hub to work with a disc and factor in the (disc)offset in the fabrication of the hub.

The old (KZ) discs are what are considered wide band rotors. They use the height of the brake pad to contact the "wide band" of the rotors. The newer discs are considered narrow band rotors. The use the width (front to rear)of the brake pads to contact the rotor.
Using a narrow band disc(newer disc) with a wide band (stock KZ) caliper usually have the brake pad contacting the buttons on the rotors. I would strongly advise against cutting the brake pads for clearance (they may contact the buttons when the pad wears down). I have seen 1 person do it on the CB 750 message board, and(a 3rd JMO) is a disaster waiting to happen.

my thinking was it would be easier to get parts if need be.he told me he could make it look basically like the stock hub but it would have the holes located to bolt stock sportbike style rotors on without having to modify things everytime you changed a brake rotor.
like ive got enough time to finish anything ive already started! :laugh:
another reason i was modeling my idea after the stock hub was to avoid issues finding spokes the right length

Still recovering,some days are better than others.

Last edit: 14 May 2010 17:49 by PLUMMEN.

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The Fish
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Re: 320mm oversized rotors

15 May 2010 04:18 - 15 May 2010 05:55

#368066

Have your machinist make a hub to disc adapter instead. I think it would be easier.(another JMO)

As used on this bike.

www.randakks.com/CBX%20Farkles.htm

Here's a link showing the hub to disc adapters being made for the CBX.

s111.photobucket.com/albums/n130/dgfisch...?albumview=slideshow

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Last edit: 15 May 2010 05:55 by The Fish. Reason: Because

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ELCouz
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Re: 320mm oversized rotors

17 May 2010 16:10 - 17 May 2010 16:11

#368578

Nice post guys,very interesting...

The Fish,
BTW, i have only access to a waterjet cutting machine( no mill or lathe). I know the cutting doesn't generate heat thus no distortion whatsoever.Is the warping of the adapter critical? What is acceptable for the tolerances?

I might go with your idea but I'm afraid to loose my money. Rotors on eBay are frigging expensive too! The guy at EBC confirmed me a bolt-on rotors at nearly the same price as the Chinese rotors.

look at a GPZ wheel...

The rotors are hold by bolts that are nearly at the braking surface and most rotors on ebay are held by bolts at nearly the middle of the hub... This mean a HUGE adapter need to be made...right?

Hope to hear from you guys...soon!

Best Wishes,
Laurent

1982 KZ810-R1 GPZ with hindle 4-into-1 pipe

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Last edit: 17 May 2010 16:11 by ELCouz.

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The Fish
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Re: 320mm oversized rotors

18 May 2010 04:51

#368692

The guy at EBC told you that the Vulcan rear disc would bolt on to your wheel. That would be the best place to start. Buy a used Vulcan disc and see what would need to be done to get it to work.

As far as I can tell, you would need to have the Vulcan disc shaved down to 5mm. Since the disc is supposed to bolt on, it would make no sense in making an adapter for the disc.

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