Forks breakdown

[Nice_One_Son]

Hi All,

I am just about to start to take the forks apart. I have the Clymer manual, but it doesn't seem that clear.

Any tips before I start please?

Cheers

Chris

[Bob_Roller]

About the only problem areas are getting the wire circlip out of the top of the fork tube to begin the dis-assembly process .

You need to push down on the top plug, while trying to remove the circlip, sounds a lot easier than it actually is !!!!

The other is getting a 13 mm socket down inside the fork, while using an allen wrench on the bolt at the bottom of the lower fork tube, to get the damper assembly out .

I take the forks off of the bike and place a couple pieces of wood in the jaws of a vise to hold the fork during dis-assembly .

[Rob Valdez 79 R65]

There is a lot of information on here about rebuilding the forks.
Here is a post of mine with two relevent links: http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1270506405/5#5

And when it comes time to refill them, you might find this tool, from Mike's XS supply to be useful:
http://www.mikesxs.net/products-7.html


Fork Oil Level Gauge for adjusting the oil level on all XS650 forks.
Adjustable ring measures oil levels from 0-300mm. in 50mm. increments.
60ml. capacity syringe adjusts fluid levels.   $15.00 USD Ea

I went to Tractor Supply and bought a huge syringe for livestock, but I couldn't find a tube that fit over the end quite tight enough, and the syringe leaked air, which didn't help.
I now have one of these waiting for my next fluid change.

[montmil]

A 13mm 1/4 drive socket on about fourteen-inches worth of extensions will reach the bottom on the for legs. Helped will hold an Allen wrench in the fork lower to keep the damper rod from revolving, revolving, revolving...

The circlip in the top fits into a machined groove in the upper fork leg. Get a helper. Have said helper push down on the upper fork leg cap bit. You may then use a small, flat blade screwdriver to catch an edge of the wire clip and turn it perpendicular to the axis of the fork leg. Then, grab it with needle-nosed pliers and pull it out.

Sounds difficult. Easy with three hands.

The fork spring will want to come out so be careful with sensitive body parts, such as eyes and teeth.

Monte

[mimmo66]

I have two sets of front ends and rebuild them every year alternatively as to keep a set  ready to install at hand.

Some of the lessons I've learned on the 81 onward model:

Use a vice to hold the lower as you undo the retaining allen screw,  it helps!

Do not use any choke cleaner in the lowers as it will melt the damper rubber at the bottom, guess how I found out?

You can make an easy jig that bolts on the upper triple and screw in/out the top nut as you remove the top circlip, very easy to do and effortless, just need one hand!

Upun rebuild use thread sealer and some loctite blue on the bottom allen screw and let dry before refilling, otherwise leaking might be a possibility.

Bump up the fork oil level to 280/300cc with 7.5weight and if you have good stock springs it will work great, same as having progressive springs from my second set.

When remounting the forks ( this might be the time to install gaiters)   make sure they are aligned.
The axle (slightly lubed) should go through the whole assembly with little to no effort,
it helps if you leave the double triple bolts securing the fork tubes a little loose as you're refitting the whole assembly, don't forget to go over all the bolts to make sure they're tight once done!

Hope this helps
Domenico

[Rob Valdez 79 R65]

Yes, those top caps that have to be pushed down whilst digging out the circlip - I didn't have a seal-puller (I think that is what some have used), and as I do most of my work in the middle of the night, I couldn't call on my neighbor.  

After some frustration, I decided I needed more weight on my side.

This is the tool I came up with.  That is the handle to my impact screwdriver:



Here are some photos from my 1979 forks.  I'm not sure, but '81 internals may have differences.
http://www.pbase.com/tomfarr/gallery/forks

[Barry]

Bump up the fork oil level to 280/300cc with 7.5weight and if you have good stock springs it will work great

Domenico

That's a pretty radical increase from the stock 190cc (or a little more if the forks have been rebuilt).

I might try it  Do you know what level that gives you using the dipstick method (normally 20 - 50mm above the damper piston top)

Do not use any choke cleaner in the lowers as it will melt the damper rubber at the bottom

I'm curious about which bit of rubber you found. Unless my forks are missing something there is nothing made of rubber in the lower fork leg (except the seal). There is only the topping out bush in the fork stanchion and the new ones I bought are more like polyurethane.

[Nice_One_Son]

Guys,

As always a big thank you.

I'll let you know how I did...

Cheers

Chris

[suecanada]

Is it wise to use some duct tape or something to make sure the rachet extender and it's 13mm socket stay together and not come apart inside??

[mimmo66]

I'm curious about which bit of rubber you found. Unless my forks are missing something there is nothing made of rubber in the lower fork leg (except the seal). There is only the topping out bush in the fork stanchion and the new ones I bought are more like polyurethane.  

Barry,

The part I am referring to is called Support for Damper Pipe #18 as listed in the attached picture, whatever it's made of it melts with carb cleaner guaranteed.

My oil quantity of 280cc is just a subjective information as I've tried 220 cc to 250cc with very little difference than the reccomended oem level.

This considering I'm about 170 lbs. fresh stock springs, no preload spacers, and about 20 lbs of dead weight from miscellaneous items I carry at all times. When touring I easily add up to 50/60lbs of extra load.

Just like any other aspects of tuning, forks have many variables that can be changed to attain different results.
If you're not satisfied with your current setup try play with it till you get it to where you like.

Ciao,
Domenico

[Rob Valdez 79 R65]

Is it wise to use some duct tape or something to make sure the rachet extender and it's 13mm socket stay together and not come apart inside??

Only if your ball & spring on the connections is not tight, I would say.

[Barry]

The part I am referring to is called Support for Damper Pipe #18 as listed in the attached picture, whatever it's made of it melts with carb cleaner guaranteed.

Item 18 does support the damper rod or at least centre it at the bottom of the fork leg but they are more commonly known as an oil lock piece. It's purpose is to provide a hydraulic bump stop as the slightly tapered top hat shape enters the lower part of the damper valve body during the last few mm of fork travel.
 
Mine was made of metal and I thought they all were on R65's but you live and learn.

[nhmaf]

I've found that ~230cc of 7.5 weight oil seems to work pretty well for me with a full drain/rebuild in each fork leg.

[R65Guy]

You can make an easy jig that bolts on the upper triple and screw in/out the top nut as you remove the top circlip, very easy to do and effortless, just need one hand!

Domenico,
Any chance you have any pics to share of your jig.  I am getting ready to build one before diving into my fork rebuild project this winter.  No need to reinvent the wheel, errrr I mean jig, if I don't have to!  I did it once before without a jig and told myself - not again!
Thanks for all your input.
Neal

[nhmaf]

Neal !!

Long time, no see!

It sounds like this fixture/jig could be very helpful to all of us who sometimes can't get a helping hand in the garage..