Stripping Down XJ900 Forks - 26 Pics

Yup I've been at it again....

Later model forks than my bike with no Anti-Dive system....

 

Nice job, good pics.

They looks like XJ900F forks (ca. 1991-93) - I have stripped mine down more than a few times trying to get em stiffer.

On mine, these seem to work better than the set with anti-dive.

 

The forks I have on now have the anti dive and I'm hoping that these ones (once back together) are a whole lot better than what I have now

 

Alive,

What was the outcome mate? I have a 83 XJ900 and the front forks are terrible. I haven't decided whether I'm better rebuilding the current ones or looking for a replacement.

Cheers

 

I redid the Front Forks on my 1983 XJ900RK (USA Model)

The Damper has a different Oil Lock Piece than I'm seeing in your Photographs. I replaced the Slider and "Shimmed" the Nylon Bush.

I Pressed a 10-thousandths Piece of PlastiGuage down to .0015 in my Micrometer. Slip the "Shim" behind the Slider and the Front End (along with Progressive Springs and and additional 2.5 cm of pre-load) is Fabulous over the Road and lessens Vibration)

The Anti-dive's are Simple to Overhaul.
The Anti-dives are Difficult to Strip.

The O-ring secured Top beneath the Circlip is a BEAR to get moving out.
Once it comes free ...
You only need to refinish the Inside Diameter of a Nylon Bushing to Allow the Cylindrical Piston to have "Travel" again ... and they work beautifully!

 

So where did you get that neat little socket tool? There is going to be some interest in that. Nice pics of how those look when they start to leak. Rust and crud that you couldn't even see takes them out.

 

Haven't finished them yet... Got put on hold when the weather started cooling down and we went on holiday, then shifted... Sometime soon I might actually find the time to finish them off

 

Great pics ..... planning to do the seals on my XS this weekend (if my parts come in)

 

What is the socket on the end of the extension bars?, my forks are very similar and I'm presently trying to pull them, the bottom allen bolt
just spins.

 

Found it, it is a splined recessed bolt, a 21ml allen key fitted.

 

It's a multi socket tool I bought from a local bike shop...

Similar to this

http://cgi.ebay.com/ebaymotors/SPORTBIK ... _776wt_939

 

were the seals you took out upside down ?

 

No... Why do you ask?

 

shouldn't the open side of the seal with the spring go towards the oil
and the flat side where the numbers usually are go up towards the air?
or am i not seeing something right

 

These seals had hollow undersides... the numbers were facing up on the rim just below the spring... They were unusual.

 

ok, i guess their all different here is a excellent article on the topic, you might like the one on kidney belts too
:wink:

 

Awww man you really know where to find all the good oil... *wanders off to do some "READING"*

 

That's a good tool, can't find it in Australia though. seller does not post international.

 

This one does

http://cgi.ebay.com/ebaymotors/Motion-P ... 27b0e78e65

So does this one
http://cgi.ebay.com/ebaymotors/Motion-P ... 27b0e779fd

and this one
http://cgi.ebay.com/ebaymotors/INTERNAL ... 19bb062424

http://cgi.ebay.com/ebaymotors/Tusk-Hex ... 27ab0d1241

And then there's the one in Australia

http://cgi.ebay.com.au/Motorcycle-front ... 43a0ffe12f

I searched for "hex axle tool"

 

@polock I was checking out the kidney belt link about half way through I forgot what I was looking at. In other words good link ;-)

 

Excellent pics. They are the same forks as on my XJ900. I rebuilt mine with parts from Chacal: new bushes, Progressive springs etc. The old springs were so sagged they sat about 25mm below the top nuts.

To reach the damper rod, I made a tool with a hexagon nut that was 22mm across the flats and welded it to a long piece of 20mm RHS.

 

Got one of those tools coming, only wish I'd found it before I bought the two Allen Keys I needed.
My 85 XJ 600 forks are the same construction type as these.
The images were very useful,

Thanks Alive

 

You're welcome

 

Great information I will be ordering that hex tool here shortly. I have forks to rebuild thanks for everybody being so helpful and willing to share

 

Polock once again thanks for posting!!! I think now I will go back and read your post on the forks

 

Did you notice she carried out the compleete operation without getting her gloves dirty, amazing. 8O

 

Alive, youare a genius, a life saver and a mind reader.

I am new to bikes and I have been lamenting about the forks on my XJ750s. I have been desperately looking for some new inner tubes in Aust without much success. On two of the bikes the inner tubes appear tobe salvageable and I was this very afternoon login in to ask for some pictures on how to dismantle the forks ....and presto, you have already done it. Great photos and it helps a lot.

Thanks.

Wiz, I take you point about the gloves, but I somehow missed it. I must have been concentrating too hard on other aspects of the pics

 

Gloves??? What Gloves?

 

Dookus, who did you order through. I looked at one which was $29 and would you beleive $49 for freight!!!!
Which part of OZ are you in?

 

I bought mine from a local bike shop

 

Hiya,

What size Allen Key do i need to undo the fork top cap bolt pictured below ??



Cheers,

aPoPhus

 

One that fits

Sorry, I don't have a top cap to hand nor can I remember what size it was, but what I used instead of buying a huge allen key I'd only ever have used for the fork caps, was a bolt with the right head size, turned upside down & slotted into the cap. with a couple of nuts locked together on the bolt I then used a spanner on the lower nut. Once it was loosened I just unscrewed it the rest of the way with the ball of my thumb (that way I had it under control when it reached the end of the threads...)

EDIT-: I have a feeling it was a 15mm headed bolt I used...

 

front wheel spindle fits with a couple of Extension drives, and your two locknuts. :wink:,or it may have been the rear engine bolt through the footrest casting,i'll check in the Morning.
EDIT
Rear engine bolt undoes cap with locknuts as you say ,with extension drive it will also remove damper rod assembly from fork tube if it rotates when you try undoing allen bolt at the bottom of the fork tube.i remember now......

 

ok guys, why did i not think of that lol

Cheers,

Rain Man

 

That'd make it 17mm then :? Hmm, I must check now, sure my top caps were 15mm and the damper rod was 17 as you say...

 

I've just discovered my fork legs are of uneven spring rates, so had to take them apart to find out what was going on. This thread was very useful, thanks.
Oddly, both springs are the same length, and when roughly floor pressing them they seem the same, but one was poking out the top of the leg by 15mm or so more than the other. Both legs contained 250ml of oil, and without springs slide freely and evenly. Looks like there may be an unexpected spacer down the bottom of one.
The mystery deepens.
Oh, for a top nut driver, I found a threaded rod coupler works fine. It's for coupling together two lengths of threaded rod, believe it or not. Basically, it's a long-bodied 10mm nut of 17mm across flats.

 

Well, that's the oddest thing - nothing found in either fork leg that makes it any different from the other. I put them back together and they're now both behaving identically. The fork seals aren't all that old and it's possible the PO (or whoever did the work) didn't properly fill the oil into one leg and as a result it had an air lock, although I can't see how it would happen as the oil should just displace air as it goes in. There was a good old gurgle in one leg when I filled it, and I made sure to work each one up and down to dispel any air before the springs went it.
All sorted now, back killing me, ride it tomorrow.