The International CBX Owners Association

OK note in this post I was doing a 400F fork, and NOT a CBX, so there may be differences. Don't get fooled!

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These little copper sealing washers are NLA from Honda and besides, it's easy enough to re-anneal them, so we did. Pulled them off the bolt by sneaking a razor knife in the edge to pop them free...




Heat them till red hot with the MAPP gas torch, no more than 5 seconds.




...and drop them into cold water to quench them.




Touch them with the wire wheel to get the scale off, and they are good to go.

Again, note that this is a Honda CB400F fork, some of this wlll not look like a CBX fork:

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I think these are called "oil control rings" and they sit in that slot on the damper rods. Old one at left. Replaced these...




Blast the fork legs and new fork tubes clean one last time, drop the damper rods into the fork tubes with the new oil rings, wiggle them through the bottoms, and then use the fork spring to hold them there while pressing on that T-shaped piece that sandwiches between the damper rod and the fork leg.






Now, carefully slide the fork tube down the leg, once gain using the spring to hold pressure on the damper rod. hold the assembluy upside down on the bench, pressing the spring against the damper rod, install the damper rod bolt and the re-annealed copper washer, and tighten. Turn it back over, remove the spring.



Chuck it up on the soft-jaw vise, clean the tube one more time, slide the seal onto the tube, and install it with a seal driver. I raided my hardware store's cut-offs bin for a half-dozen different sizes of PVC pipe, found one of them a perfect match for this seal, cut it square with my miter box, sanded it smooth and deburred it. Worked well.



Sorry no photos of driving the seals, but I had to wail on it to get it all the way in there and expose the clip groove.

Did I mention that this is not a CBX fork pictured?


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Grab the GoldValve and adapter stack, slide it together into the fork tube and try to slide it together down the fork tube using the spring, on it's side. Easier than it sounds.





With the spring and Gold Valve installed, extend the fork all the way, and measure/calculate the distance that will be from the bottom of the fork cap to the top of the spring, then add 5-10mm for spring preload per Racetech, and cut the PVC spacer material to length. 30mm in my case.



Smooth and deburr these well, you don't want PVC chips floating around your fork.



Now is a good time ti install the fork oil. I went with Honda SS8 (10 wt) at 160cc. Pour it in slowly and carefully pump the fork a little to pump the air out from the bottom.




...

Everybody say it with me here now: "This is not a CBX fork! This is a Honda CB400F fork!"

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Home stretch - drop a washer in on top of the spring, then the spacer, then another washer, then the fork cap.

Install the dust seals:




Get rid of your greasy fingerprints...




Declare victory.

Next!

Nils, an excellent tutorial but are you sure those are CBX forks?

AAAAAAIIIIEEEEEEEE!

Nice job, Nils. looks really easy when you do it.

We understand that these are not CBX forks.
Clearly tHey are Honda CB400F forks.
I just don't understand why you are putting them on your CBX bike.









Barry

barryadam wrote:Nice job, Nils. looks really easy when you do it.

We understand that these are not CBX forks.
Clearly tHey are Honda CB400F forks.
I just don't understand why you are putting them on your CBX bike.





Barry

They're probably a nice upgrade in the handling dept.

This is a nice write up, thank you nils!
I spoke with the guys at race tech and they had suggested that the spring is most likely not their as their is shorter.
Which fork did you use? Stock or their fork? What is the improvement?
I ordered washers and spring clips and it will take few days for them to arrive, everything takes a week to get for this bike.
Race tech turn around is 2 weeks for fork rebuild and that is too long to wait
Thanks

I am so Jealous !!
I still only wish for a nice CB400F :-(
Great tutorial Nils, thank you.
Best,
Phil

Two weeks IS NOT too long to wait for these things. I've said it a million times - take your time, don't rush and do it right the first time, 'cause if you don't, you will eventually.

Dave

cross wrote:This is a nice write up, thank you nils!
I spoke with the guys at race tech and they had suggested that the spring is most likely not their as their is shorter.
Which fork did you use? Stock or their fork? What is the improvement?
I ordered washers and spring clips and it will take few days for them to arrive, everything takes a week to get for this bike.
Race tech turn around is 2 weeks for fork rebuild and that is too long to wait
Thanks

Thanks for the bon mots fellas, my pleasure.

Sasha, not sure what you mean by 'which fork did I use?'. On my '80 CBX I had powdercoated my lowers, my tubes were good, and that time I sent the whole shebang to Racetech and let them do the install - at the time it was a whopping $75 plus the parts. I think it's higher now, Syscrush (Phil) just looked into that I think. $200?

The damper rod forks are a really primitive design, the entire damping action is limited to forcing oil in and out of those holes in the damper rods - no valving, no nuttin. The Gold Valves work by first bypassing the damper rods (by drilling them out and letting oil flow freely), and then installing a new damping circuit in the form of that gold valve. The damping is what prevents the fork from simply pogoing up and down when you hit bumps and imperfections. Better damping = better control of the front end and a more stable and settled chassis that isn't introducing lots of weird steering inputs as the bike rises and falls.

The Gold Valves are a 'better than nothing' solution to improving the primitive front suspension, however the Traxxion cartridge inserts that Syscrush just installed ought to be the cat's ass.

FalldownPhil wrote:I am so Jealous !!
I still only wish for a nice CB400F :-(
Phil

Phil: I know someone (Doesn't everybody )who has two CB400Fs, a blue and a red one. Both impeccable. He was going to sell one, Preferably the red one. This was in November.
I can ask him if he still has it.

Mine is going to be nice

Nils,

What I meant was which "spring" did you use, stock or racetech?