Is it possible to shim the XTZ 660 front fork? The springs don't have enough preload for my weight + loaded tank bag + full tank. I am thinking a 20-40mm shim would be the beez kneez.

If this is doable, are there aftermarket shims that will work on this fork, or will I have to macgyver something myself?

edit: It's a 1994 model.

Wilbers sells aftermarket progressive springs for around 70euro a set, on the german ebay. I can highly recommend them!

Or a stack of fat washers !!

__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

But will they improve preload? Also, is Wilbers better than Wirth?

Either way I will try shimming first -- I am quite happy with the suspension (not an advanced rider, to put it mildly).

Yes they will, the bike will sit up more straight, and dont dive so much when braking.

As stock, theres a spring and a big pipe that acts as a spacer. The new springs are so long that you dont need the big ass pipe/spacer, so you get a much more functional suspension.

Havent tried wirth, but theres not much difference price-wise, so I went for wilbers, as did my friend. We know they would work, makes no sence to gamle for a few bucks

Allright, is it an involving procedure to change the springs? Do I have to take the fork legs off, or is it sufficient/possible to take the cap off the top and pull the springs out?

Maybe I should take a look in my repair book before posting more newbie brainfarts on this topic (:

you can get away with just removing the caps, but I would suggets to do it "right" so you can empty all the dirty oil, and poor fresh in aswell.

The stock springs ARE progressive anyway. The others are just stiffer if im correct ???????????

I really would try adding more preload with spacers/washers before spending money. Although, depends on your budget.

I put some hefty washers in mine and it made a drastic improvement. Worked perfectly all over South America and the bike is still there now doing just fine !

__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

They werent on my buddys 1992 xtz660.

Adding spaccers is fine, but then you wont use al of the fork travel, making it worse for offroading. If it's bottoming out, something is worn, bad, og not enough oil.

peaople tend to use more, and thicker oil, cause whats already mentioned. Just get the spring and be done with it.


Sidenote: The springs on my 2003 xt600e was progressive, but not as much as the wilbers, and because the wilbers springs are longer and you can loose the big pipe-spaccer, you get much better suspension.

Its a real shame that i cant find the pics of the difference, its one of those "a picture is worth a thousand words" thing.

**** me, I found the pic, this is the 1992 xtz.

You tell me what ya thing works best:

Holy crap! Well that settles it then.

Is it correct that the following Yamahas use the same types of spring? (excerpt from Zietech on ebay.de, these are Wirth springs)

Also I called my local motorcycle repair dude for a quote on changing springs, seals and oil -- £300 for the job! (parts not included!) Yikes! Maybe I should check some prices in Sweden.

Im sure we can guide you, i did the job and have som pics for the operation.

Its really simple, no small parts and small springs popping out from everywhere. Pleeaaassee...???

Wish granted!

The part that freaked me out at first when I did the seals on my USD forks was the way to pop out the old seals..

on mine it said to take everything out of the forks and as much oil as one can and then take the dust seal out, then the the seal spring.

To take the dust seal out be VERY CAREFULL not to damage the chrome part! use a blunt screw driver and do it calmly!

Then came that freaky part... using the fork as a sledge hammer... "compressing" the forks a bit an then give it a go and pull it out with some steady blows lol

On the first fork I had to do it about 15 to 20 times to pop out the old seal because I was afraid to damage anything lol

The second one was easy 3-4 times..


One thing one should always do after refitting the new oil seals is to press and decompress the shock about 20-30 centimeters on the travel NOT THE WHOLE WAY DOWN! and check if it is all smooth with no tight spots!

If there is any tight spots, take the seals out and repeat the process!
Also, you should use your old seals to fit the new ones into place! cut the old ones in two pieces and fit the pieces nicely over the new ones so you don't damage the new ones with the seal drive tool (you your's is a selfmade tool!

(I did my drive tool... small piece of PVC tubing of the same ID size of the fork and a cut through it so I could fit it around the USD fork and tightened with those metal braces)


The only two differences I can foresee here with the convencional forks is you won't need to cut the old seal in two parts nor is there any need for you to cut the PVC tubing like I did because these two can come out from the top of the fork


OHH and to clean your forks interior, use petroleum and use a air compressor gun that has that bottle on bottom or top like a normal painting gun and let it dry off!!


Sorry for the long text!

Vando

AND DON'T MIX PARTS FROM EACH FORK!!


Vando

Bacardi, he doesnt need to change his seals, so the operation is very simple.

-Put the bike on a stand.
-Remove the speedocable from the front wheel.
-Remove the brake by unscrewing to bolts. Twist the caliber back and forward, and remove it by sliding it backwards.
-Loosen the 4 nuts on the lover part of the right leg. After that you can take out youre front axle, do that.


-Loosen the upper mounts for both the legs, 2 bolts on each side.
-Now do the same for the lower ones, theese are 2 bolts and 2 nuts on each side.
-Loosen the top "cap" of the forks, just loosen them a turn or so.
-Slide the legs down, they are now off the bike.
- Take the top covers of, remember you loosend them before, now they're easy. If you can, put some weight on them to save the threads a bit.

-When you get them of, you will se the spacer, then a washer, and then the spring. Remove that, and set the leg upside down in a bucket. Pump the leg up and down to get all the oil out, and let it drip of.

-You're now halfway done, i usualle poor one cup of oil down the legs again, pump the leg up and down a bit, and then turn it upside down, and pump it again,. and let i drip of. Thats just to get all the dirt out.

-Now, compress the leg, and poor oil in it to 18-16cm from the top, depending on how hard you want it. You need 550ish ml to do that.
Just use some 10W fork oil for the job.
-Now its all backwards, remember to put the new springs in correctly. The end which is tightest together should face up.

It kinda sounds like much, but it isnt. You're jsut removing the front wheel, taking the legs of, and take the springs out, and change the oil.

Making sence?