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

[Larry Zimmer]

Outstanding - both concept and workmanship.

[Jeff Bennetts]

Very nice, love your skills!

[RC 166]

512tr, Thanks!
Yes, I will use a main stand on it. It will be custom so it can take the 180 rear tire and use an upper stop, independent from any exhaust pads.

Dave, Thanks!
And if you look at the headlight again, please notice that the rubber hose, used at the lower clamp for the headlight rods, slid down before I clamped it. Should be up there fully covered by the gold clamp bar. doh...

Rick, Thanks!

Larry,Thanks!


Jeff, Thanks!


Rear wheel:

I have done a huge amount of measurements and CAD drawings in order to get this project as spot-on as possible.

For the rear wheel I could use all important OEM parts as designed except:

-Sprocket side wheel spacer made narrower.
-Cush drive. Sprocket studs shortened 2.5mm to clear the left shock mount.
-New caliper bracket for the OEM ZX-9R caliper to match right shock mount with integrated caliper guide web.
-New custom rear sprocket adapter that moves the rear sprocket inwards (needed for correct chain alignment) and thereby avoiding shaving the cush drive. And, the 18T front sprocket is flipped so chain path is moved out from engine.
-New custom made sprockets from sprocket blanks.

20231106_084941crop23 (2).jpg

20231113_115521crop26.jpg

20231113_122430crop27.jpg

20231103_114306 crop17.jpg

20230925_124221crop (2).jpg

I also have Ohlin shocks for this build.

DSC02869.JPG

Cleaned brake discs. I loosened the stuck bobbins on front discs so now they are really semi floating discs.

20231113_141243crop29.jpg

20231202_120023crop42.jpg

20231202_120120crop43.jpg

20231202_120158crop48.jpg

[RC 166]

Part of fitting a 180 rear tire instead of the OEM 120 tire is proper chain alignment. Luckily the front sprocket is an easy one, as it is offset by 6 mm and I just flip it so the teeth face outwards.

20231109_111024 (2).jpg

As I am still plenty busy completing the rolling chassis, I need to check the chain alignment as soon as I fit the rear wheel. The engine will however not be mounted until it has been overhauled so I pulled a new trick to get around that. I CNC'd a simple sprocket bracket to fool the frame to believe that the engine is mounted with rotating sprocket and all. This is carefully measured and the sprocket position is exactly where it gets later on the engine.

20231114_174424crop31.jpg

20231114_174520crop32.jpg

20231114_194418crop33.jpg

20231114_194554crop34.jpg

[steve murdoch icoa #5322]

Great idea on the stand-in front sprocket.
Spectacular skills, Peter.

[Larry Zimmer]

You, sir, are near incredible. This is a fantastic project to follow. Thank you for the sharing.

[Jeff Bennetts]

Great idea on the stand-in front sprocket.
Spectacular skills, Peter.

It sure beats the string or masking tape method!

[steve murdoch icoa #5322]

Great idea on the stand-in front sprocket.
Spectacular skills, Peter.

It sure beats the string or masking tape method!

You and your fancy methods. I remember the after six beers "that looks straight to me" alignment.

[RC 166]

Thanks Steve, Larry, Jeff!


Front End - Triple Tree:

Like most custom builders here, I also found it necessary to use the OEM steering stem which works very well.

20230105_101815crop97.jpg

A bushing has to be made due to diameter differences at bottom yoke stem bore. This bushing also serves as an axial spacer between
the stem flange and the ZX-9R bottom yoke.

20230105_101826crop101.jpg

I did not want to modify the CBX steering stop, so all changes were made on the ZX-9R bottom yoke. I milled off the two stops and designed a new bracket/stop post to exactly mimic the OEM CBX bottom yoke. This part then mounts right behind the brake line coupler on the ZX-9R yoke.

20230104_115723crop99.jpg

20230104_123717crop100.jpg

Unfortunately the drop-down top yoke interfered with the gas tank so I had to modify my steering stop to decrease the steering angle.
Hope this will not be a problem when driving.

20230213_133437crop104.jpg

20230215_085937crop103.jpg

Complete triple tree assembly. Later I also changed the CBX top nut to a chromed M24 x 1 nut, think it was from Suzuki GSX-R1100 '92 (more bling).

20230105_103050crop102.jpg

[RC 166]

OK, got forks with 46mm stanchions. Any risk for wobbling at speeds over 85mph now?

Anyway, I have a traditional (long) WP steering damper that was used on a Suzuki GSX-R1100 '92 in its OEM mounts. At the fork leg it looks OK, but is very ugly at the rear outside of the tank, protruding out from the bike and then poking out the damper rod on top of that. I also looked at the small Moto GP type dampers, but thought it would involve more work to attach (under the headlight).



Decided to use my long WP unit but hide it so you barely can't see it. Works beautifully, only a few mm side movement while operating between steering locks. I need to move the ignition coils around a little, but promise it will be tidy. The clutch &throttle cables cleares OK though.

20230406_162842crop106.jpg

20230406_163517crop107.jpg

20230406_163443crop109.jpg

20230406_163526crop108.jpg

20231202_115941crop110.jpg

The exposed, moving damper rod is a hazard under the tank as it can catch wires, hoses etc and cause steering lockup and/or damage to vital components under there. So I made a protecting sleeve that covered the end so nothing can get catched by the rod.

20230413_171202crop 111.jpg

20230413_171121crop.jpg

20230614_163704crop112.jpg

[512tr]

Will you be able to fit the coils with the steering damper that way?

[RC 166]

512tr,
Not OEM position. I will move them around a bit, but it will be nice and tidy.

[512tr]

It will be a tight fit.

The oil cooling hoses… wire harness, throttle cables, choke wire and clutch wire go there and move a little when you turn the front wheel... same with the steering damper.
The installation of the carbs, installation of the throttle and choke cables, syncing of the 3/4 carbs will probably be a little more challenging with a setup like that. But I’m sure you've thought off all that

Are you disabling the possibility to adjust the stiffness of the steering damper with that tube over the damper piston?

On my bike I used a short steering damper, from the fork tube to the oil cooler bracket, it works and looks ok.

[RC 166]

512tr,

I am mostly worried about the throttle cables coming up on the left side where my damper is. I will probably have to mount the damper on the right stanchion instead. That's no problem since my brackets are symmetrical (flippable). As for the other cables, wires, hoses I think they are flexible enough to tuck in. The clutch cable is already there and will be OK.

As for installation of carbs, throttle cables, choke cable and syncing 3&4 carbs, no problem. If the damper interferes, I just simply drop the rear end from the frame bracket and swing it out of the way.

No, I don't intend to disable any possibility to adjust the stiffness of the steering damper. One way is to drill 2 holes axially in the knob so i can use a simple tool to turn the spindle.

[512tr]

As I thought, you have it all figured out
Looking forward to following the rest of the build.