XR4 fork noise, negative preload?

mtngoat

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#1
One of my XR4s makes a subtle clattering when the fork is un-weighted. The other does not. Both have suspension work. SRC advised me that XR4s have negative preload resulting in a gap around the spring/cap area, which could make that noise. I don't understand why one does and the other doesn't. Anyone else notice this on XR4s?
 
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#2
Hello,
My '96 XR4 forks do not make any rattles. It definitely sounds as if something is loose in there. I'm not real familiar with fork guts, but that sure doesn't sound right. Get it checked out. Good luck. Keep on thumpin'!
 

TR

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#3
>>>SRC advised me that XR4s have negative preload resulting in a gap around the spring/cap area, which could make that noise <<<

Maybe you misunderstood what SRC were saying. There is no "negative pre-load". Check that the forks still have oil. If they do then the forks will have to disassemble and inspected.

Regards
TR
 
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#4
FORK NOISE

Mtngoat, my xr had the same thing happen. I increased the preload by half an inch using the good old pvc pipe method. No more noise, and the bike handles better for me, 200+ pounds. Good luck.
 

mtngoat

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#5
Thanks for the replies. I didn't mis-understand SRC. To elaborate, they explained the "negative pre-load" means that fork springs are shorter than inside tube length when fully extended, causing the "subtle clattering" when I ride un-weighted. I'm still curious why some do and some don't. I did notice looking at fork spring specs that a few years after the XR4 came out, spring length was increased about a inch on newer models, but I alwayas figured Honda did so to address the common complaint about soft XR front ends.
 
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#6
I recently replaced the springs in my XR400 with Race Tech .44 kg/mm units. The stock springs I removed definitely had what you would call "negative preload". I didn't measure it but the clearance was roughly .25 - 3/8 inch. I cut a spacer to give me 15 mm "positive" preload with the new springs. Much better ride now.