2003 KX 125 Fork

Questions and comments about converting to beefier forks..
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rdsrf
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2003 KX 125 Fork

Post by rdsrf »

Just got a 2003 KX 125 front end to swap on to my 2000 KDX 220. Anybody know which years will fit it for wheel/hub/axle assmebly? I'll be using my KDX brake set-up. Is knurling required? Also, what revalve/spring mods are recomended? Are there bladders that need to be removed? I'm 5'7" 170 and I ride very tight, muddy woods most of the time. Thanks for any help!
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krazyinski
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Post by krazyinski »

I can tell you the forks will need re valving, go one lighter on the fork springs
the the spring rate calculator will call for .42 fork springs I would recommend
.40 from experience the KDX just responds better to a softer front end.

I also have a KX250 with .42 fork springs and it works and feels fine but the
.42s in the KDX and it was a jitter bug.

just my humble Opinion.

Matt
2000 KDX220 FRP Ported,plated cylinder,milled head, FRP bored carb, V force 3 reeds, FMF desert pipe, 10oz FWW, 98 KX forks and oem shock re valved by Pro Action, hyd clutch, fastway pegs, tall seat foam, gripper cover, 29" CRhigh mini bars, Cycra brush gaurds.
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Indawoods
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Post by Indawoods »

At 170 I'd be tempted to go with .38 springs. I am 215 and have .42's in my 03 KX 125 forks and they are stiff! If course that may change when I revalve them (remove 2-4 of the largest shims in each valve).

Mine did require knurling....
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jc7622
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Post by jc7622 »

I have '03 KX forks on my '05 KDX. I didn't have to knurl. We just pressed out and pressed in. Didn't use any Loctite pressfit goop or anything. I used the KX steering stem nut as a spacer then used some shim stock around the top of the stem inside the top KX triple clamp. I bought the shim stock at Hobby Lobby. It was basically a small sheet of very thin aluminum. I cut it to the right size and then bent it around the stem until it slid down into the top triple clamp hole nicely. Very easy really. I also posted some pictures of how I re-mounted my headlight in the furoms.
rdsrf
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Post by rdsrf »

Thanks guys! Krazyinski, did you use shim stock as well? Is a custom bushing a better idea? Where can I get fork springs? You guys left the valving stock and just changed springs? Anybody know what year wheel assemblies will fit the 2003 forks?
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TWMOODY
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Post by TWMOODY »

>|<>QBB<
rdsrf wrote:Thanks guys! Krazyinski, did you use shim stock as well? Is a custom bushing a better idea? Where can I get fork springs? You guys left the valving stock and just changed springs? Anybody know what year wheel assemblies will fit the 2003 forks?


I think MonkeyButt has the best price on race tech springs.
Also check out India's post on KYB's and look at the section
for the mid valve conversion.

http://www.kdxrider.net/forums/viewtopic.php?t=478
Race Tech also recommends this conversion.

*Note* Check the out side diameter of the fork tubes before you buy parts
46mm 2001 and older/ 48mm 2002 and newer
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krazyinski
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Post by krazyinski »

I used shim stock never had any problem. I do think they will perform much better with the correct valving and shims for your riding conditions.
2000 KDX220 FRP Ported,plated cylinder,milled head, FRP bored carb, V force 3 reeds, FMF desert pipe, 10oz FWW, 98 KX forks and oem shock re valved by Pro Action, hyd clutch, fastway pegs, tall seat foam, gripper cover, 29" CRhigh mini bars, Cycra brush gaurds.
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Post by thirteen »

krazyinski wrote:I used shim stock never had any problem. I do think they will perform much better with the correct valving and shims for your riding conditions.
TWMOODY,

I got the 2001 KX 125 forks and I have a 2004 KDX 220R - you mentioned the size of the 2001 and older being a smaller diameter - is this a problem?
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TWMOODY
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Post by TWMOODY »

You will need to buy for the 2001 kx which should be 46MM.
The 48mm's will not fit.
Measure the size of the fork tubes BEFORE you buy.
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