CBX '79 With Kawasaki ZX-9R & Yamaha FZR1000 suspension

[RC 166]

Hi everybody,

My way overdue CBX Z project gets rolling....

I am about to update my CBX with essentially ZX9R '99 (C2) chassie parts. The various gathered parts have been laying around many years due to all kind of other "everyday life issues" that came up all the time. However I at least kept planning and engineering the project in the mean time.
I have also made a lot of parts needed for this upgrade during those years thanks to access to CAD, CAM and CNC facilities in my small 1-man CNC-shop that I run. And now I have started to build the whole thing together.

I bought this some years ago. 46mm stanchions !!!

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Then, one year later I saw this, so I thought I must be on the right track. A '79 rat bike with ZX-9R '99 parts. Yes, it has a Blake turbo kit. The most popular bike at the 2007 CBX Euro-meet.

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The Turbo kit produce some nice power (hence the oil cooler), especially torque. look at the tiny rear sprocket. This one has single shock suspension and the ZX-9R swing arm which I didn't like (also too long).

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Well, lets look at the project, starting with the rear end. Like many of us, I bought a lot of different front ends and swing arms to check which suited best for the CBX.

GSX-R1100 '92, Fireblade '92 in, CBX '79. Both were too long.

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Then I found the Yamaha FZR1000 '95 swing which turned out to be a perfect match with minimal changes.

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Only minimum changes at swing arm pivot axle. I milled 2mm off each side. Then I cut down the hollow 20mm Yamaha pivot axle to L=248mm and drilled it from 12.5mm to 14mm to accept the CBX 14mm OEM axle. I also had to machine off a little on the outside of the pivot tube to clear the engine cases.

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As I decided to keep the twin shocks, I need to make shock mounts. Stay tuned...

[Jeff Bennetts]

Looks wonderful, looking forward to seeing the finished product! I’m always interested in the way people address the twin shock mounting system, inboard on the the swingarm or outboard on the frame shock mounts or both, just depends on what rim and tire combo you’re going to run.

Kawasaki ZRX front and back are popular swaps too.

I’ve seen this solution a few times.

Keep us posted!

JB

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[steve murdoch icoa #5322]

Great start, Peter!
I am interested in your shock mount solution.

[NobleHops]

Great project!

[RC 166]

Thanks all,

One more pic of the Yamaha Swing arm. I also checked some geometrics.
Swing arm length (between axle centers when rear wheel is at front stop): CBX '79 =475mm, Yamaha FZR 1000 '95 = 505mm.
Wheel base: CBX '79 = 1495mm, with Yamaha FZR1000 '95 swing arm and ZX-9R '99front end = 1515mm (measured when rear wheel is at front stop and with wheels off ground).
Trail: CBX '79 = 120mm, With ZX-9R '99 front end and 17" wheels = 115mm.

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More pics, story later tonight...

[RC 166]

I did not want to make weld-on shock mounts, so designed some rock solid bolt-on ones.

Preparing the swingarm was easy, just 4 x M8 x 20mm tapped holes.

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All CNC'd alu parts were sent out for gold anodizing (same color and supplier as for Ohlins).
Here mounted on swing arm. Note the "safety flange" on inside of swing arm. Once clamped between the swing arm and wheel spacers,
there is noway they can come loose even if I would remove the M8 bolts.

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[Jeff Bennetts]

Very slick, look good too!

[steve murdoch icoa #5322]

So tidy and trick looking.

[512tr]

Very nice, what chain adjusters will you use?

[RC 166]

Thanks a lot Jeff, Steve, 512tr!

Chain adjusters are stock Yamaha FZR1000 that came with the '95 swing arm. (bolts with lock nuts). I had to make new adjuster blocks to accomodate the ZX-9R rear axle.

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I want this baby to be pretty, so I removed the paint off the rim outer edges and then polished before sending them off to the paint shop.
Gold suites a red bike much better than blue, right? Chosen colors are Toyota Gold for the wheels and a fine grain Toyota Silver for the swing arm.

This is how I sanded/polished the wheels.
I removed the paint traditionally by wet sanding and then buffed them with a 6000 rpm dye grinder
while rotating @ 30rpm on the lathe

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The finished Kawasaki ZX-9R '99 wheels ready to go on the chassis, 120mm tyre on front and 180mm on rear.

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[RC 166]

Made a proper chassis rig so I can build the bike without fear that it will fall off the lift table.

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The front support can be used both as a frame support while assembling the triple trees, or as a triple tree support while assembling the rest of the bike.

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[RC 166]

The CBX fork is 45 mm longer than the ZX-9R's. I made a custom "step-down" top yoke to handle that.
The top yoke is complete with handle bar clamps, ignition switch bracket and instrument bracket that holds the OEM units in exact original position.
I just remove the brackets if I choose other options.

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I CNC'd all alu-parts and had them anodized. The ones with non matching colors are my bad. I listed all as alu 6082 when I ordered the anodizing.
Should have separated different alu types so they could process them accordingly. The more "orange" ones are aircraft grade alu 7075.
I will make sure to strictly use alu 6082 for all parts in future.

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[512tr]

Impressive work!
Will you be able to fit a main stand with that swing arm?

[daves79x]

Amazing! I love the detail you put into the front end to be able to use the stock gauges/headlight, etc.

Dave

[Rick Pope]

Bravo!!!! Nice work!!