a few q's on front suspension

[sluggo69]

with xr400 .38 springs going into a 03 kdx with stock valving.how do i measure preload?inches please lol. how muchand what atf oil do i put in each fork. im a little confused on the metric to standard conversion.so if any of you guys have done this please list the specs you used so i can duplicate them in my bike

thanks and any help is greatly appreciated,,sluggo

 

[canyncarvr]

Put the spring in the collapsed fork.
Screw the cap completely onto the rod.
Extend the rod.
Measure the distance from the top of the spring to the bottom of the cap.
Any spacer length longer than the measured distance will be your preload amount.

Yes, I did leave out the washers for simplicity. Measure them (around 3mm), figure them into the matter. Which is to say subtract their thickness from the measured distance.

Cut a piece of 1"pvc pipe to fit. Cut it square.

You can put in oil as a measured volume. This does not take into account how much oil you didn't get out in the first place.

Oil level works better as a measurement. Make it 110mm from the top of the collapsed fork (spring out).

110mm = 4.33", or about 3 5/16"

Take a look at CDave's site (listed at the 'every kdx rider should read...' thread at the top of this forum) for more info on fork oil level and how to measure it.

Try a search.

 

[gwhII]

Sluggo, I've got a dumb question but instead of doing Metric->English conversions, why don't you just get a metric tape measure? A metric tape will only cost a few bucks from Sears/Home Depot/Lowes/etc and a lot of them will be dual anyway. It may make your life easier because you'll only have to deal with whole numbers instead of fractions. It was easier for me at any rate. ;)

Best,
Greg

 

[canyncarvr]

Yeah.....

If there is a specific measurement issue that is at hand (maybe having nothing to do with mm, but with ml?), ask.

Well....think about it some, then ask? ;)

 

[kmccune]

Originally posted by canyncarvr
Put the spring in the collapsed fork.
Screw the cap completely onto the rod.
Extend the rod.
Measure the distance from the top of the spring to the bottom of the cap.
Any spacer length longer than the measured distance will be your preload amount.

Yes, I did leave out the washers for simplicity. Measure them (around 3mm), figure them into the matter. Which is to say subtract their thickness from the measured distance.

Cut a piece of 1"pvc pipe to fit. Cut it square. 

Best preload answer I've seen yet!

:thumb:

 

Kevin