xr400 spring swap with 2004 kdx220r

[sreich]

Okay so I've read all the threads and hopefully I didn't miss something but I'm trying to replace my springs with 99 xr400 springs. I'm also trying to document the process with pictures as much as I can so I can post later. I've got eveything apart. Not a big deal. Now ready to put the new springs in. the question is they are 70mm longer then my existing spring. I have a spacer that is 90mm long do I need to modify the spacer to accomodate the longer spring or is it just an even swap?

 

[css_elfers]

http://dirtrider.net/forums3/search.php?searchid=222391

That should help ya. Or do a search in the forum called "preload spacers"

ELF

 

[Mark W]

Spacer

In a nutshell you need to make new spacers. Use 1" schedule 40 pvc. To determine the proper length, put springs in fork tubs and put the farok cap all the way. Measure the distance between the bottom of the fork cap and the top of the spring. Now add to this measurement any amount of preload that you want. I used 4mm but it is a preference thing.

Finally, and this is no joke, make sure that when you put everything back to gether you hold the fork cap in place and twist the fork tube against the fork cap to tighten. Some who have just tightened the fork cap had clicking noises in the forks when complete. The thought is that by only screwing in the fork cap puts tension on the spring.

For what it is worth.

Mark

 

[John Harris]

Everything you have been told above is correct. Preload depends on personal preference based on rider weight, ability (speed), and spring weight. Some, including me have used 10mm of preload which should give you about an 1.5" spacer. The 4mm mentioned above is about a minimum preload for you don't want the spring jiggling around loose in the fork. So that said, anything you choose between 4 and 10mm preload should give you a great ride! Easiest and best mod you can do for the money!! Ride safe - this mod will help you do that- John

 

[seancza]

don't forget to use a torque wrench on the axle cap nuts or you may snap the studs off

 

[Mark W]

Da!!!!

Yeah, don't be stupid and read the manual specs as foot pounds instead of inch pounds as is written. Who would be dumb enough to misinterpret the manual. Some idiot.

Mark (the idiot who can't read the manual)

 

[sreich]

Do I have the correct springs???

So I've finally gotten around to putting the new springs in and when I measure from the top of the spring to the bottom of the fork cap(while pulling up on the fork cap) I have 3-4mm of space does this sound right so if I want 7mm of preload I make 9-10 mm spacer??? when I put the spring old and new side by side the difference in length is that the xr400 springs are 67mm longer that original space that was in there is 90mm...HELP!!!!

 

[sreich]

Found the Answer

After more searching I found that the spring lenght is correct. I was seeing several posts referring to the new spacer as about 1.5 inches but either I read it wrong or something else was going on. I found this post "Did I build my forks right" which was very helpful

 

[canyncarvr]

There is one thing missing. Assuming you put the oem spring-centering washers back in (the cupped/flared washers that were on either end of the long metal oem spacer?), you have to figure them into the equation.

If you have 4mm of space when measured as directed, if you use both washers (about 3mm) and want 7mm or preload, your spacer would be 8mm. 8+3-4=7 You will be happier (IMO) with a good deal less preload than that (considering your spring rate choice to be correct in the first place), say 3-4mm.

Make sure the spring seat that came out with the old springs (it's clipped to the bottom of the spring) gets secured to the new springs. Well...to start with..make sure the things came out in the first place! If they didn't, get 'em out.

Consider a lower oil level. 100mm is considered 'normal'. It's a matter of personal choice...mine is 115/120.

Do yourself a big favor. Buy a set of MotionPro (or other brand of your choice) bleeders. Use 'em often (3-5 times on a day's ride).

 

[billc]

spacers

I made 7/16" (11mm) spacers and all is well. I weigh 170 without gear.