2004 kx 125 Triple clamp/ Fork Swap

djp48
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11/5/2021 9:15am Edited Date/Time 11/12/2021 11:04am
I have a 2004 Kx 125 and I'm in the market for some wheels and a suspension overhaul/revalve. Before I decide which wheelset to go with I need some help sorting out the suspension details.
What I am debating on is getting into the newer generation of fork body which involves swapping triple clamps. I understand the stop has to be modified.
Is there anything else of concern just with the swapping of triple clamps? I don't want some janky cobbled up front end.
I'm looking at 13-18 kx250f applied racing triple clamps mainly because they offer a wide variety of offset including what is stock to my bike. How concerned should I be with the offset? Should I consider changing it? The bike seems to handle well enough although I've only rode it 3 times. (New to me)
Lastly, am I missing something here? Is there a better way to get into the newer gen fork or is it going to mess up geometry some where else? I.e. front axle, fork length, bottoming?
I like nice stuff, I don't mind spending a little money. My suspension needs springs and valve job being it is not set for my weight or abilities. Its an 04 so everything is a little battle scared (fork tubes) but overall the bike is pretty nice. Going to hang on to the bike for a while.
Thank you for any positive input, Dan.
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DJV804
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11/5/2021 3:27pm
I would look for some of the older kx450 dual spring forks. Length is the same and same lug offset so you won’t mess with anything there.

As far as clamps it kind of depends what you want do, I have current 250f/450 Pro Circuit clamps that are 23.5 offset and it seems to like that. The more modern forks have better holdup than your stock ones do so it seems to like a little less offset, or maybe it’s just my style/preference.

Another big swap worth doing imo is getting a different shock adjuster from technical touch that has high and low speed. It makes the shock work substantially better. Don’t waste your time trying to retrofit a different shock into the bike, people do it and it works but it’s not the best way to do it.
djp48
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11/5/2021 4:55pm
I appreciate your input.
By lug offset do you mean the mounting point for the front axle?
What years are the older dual spring kx450 forks you speak of?
With the clamp offset is more offset more vertical?
By current clamps what years clamp are you running and are you aware of any differences in fitment between model years?
Where there any surprises with the clamp swap or is it direct other than the steering stop?
Thank you on the tip for the rear shock The rear shock was next on my list for research. That is awesome and I'll definitely look into the adjuster. Also appreciate the tip on the hold up for the forks.
DJV804
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11/5/2021 5:18pm
Any triple clamp 2006-2018 will interchange and all you need to do is the steering stop. I’d recommending matching your clamps to the gear of fork you buy so you know they’ll fit, the outer tube diameter has changed a bit here and there. I believe you’ll want 06-12 kx450 forks. They’re Kyb AOSS spring forks. Unless you want air that’s what I would tell you to get.

I have Showa a-kit forks on mine and specific PC clamps for the Showa a-kit fork(not bored out production clamps) so they aren’t a specific year, just 23mm offset and for the kxf.

Lug offset is the centerline of forks to the parallel center line of the axle. To my knowledge that hasn’t changed on the Kx/kxf bikes at all.

Triple clamp offset is the fork centerline to the parallel steering post center line. You’re essentially making the chassis longer or shorter, then sliding your forks up or down in the clamp with change your steering angle and weight in the front of the bike.
djp48
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11/5/2021 5:49pm
I really appreciate you taking the time. Cleared a lot of things up for me. Cheers!

The Shop

Phillip_Lamb
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11/6/2021 7:33pm
my brother has an 04 kx125. he swapped a SFF fork and oem triple from a 12 kx250f. its a huge upgrade over the old kybs. he hasnt revalved and resprung for a 125, he hasnt had issues but its recommended
djp48
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11/7/2021 5:40am Edited Date/Time 11/7/2021 9:43am
I'm going to do the swap.
I'm going to get in touch with some triple clamp manufacturers and see if they have any input on the clamp offset and any other changes in dimensions between model years.
Trying to decide whether to go with air (tac) or spring (aoss)
I'll probably stay away from the sff spring fork.
Have to also see if there are any changes in fork length to consider.
Don't know much about the air forks. I like the idea of the weight savings but see a lot of people have issues with tuning and some say they are great.
Either way I go I'm going to do a revalve.
Thanks for the input.
gristle568
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11/7/2021 11:43am
Put a set of 2011 sff off a 2011 kx 250f on a 2004 kx I rebuilt a couple years ago. You need the triple clamps, forks, and the trick eng steering adapter. Forks are a little longer so you need to run them 10mm up in the triples. wheels and brakes will bolt right up but I used a set of take offs from a newer 250f.
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djp48
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11/8/2021 8:36am
Nice bike.
Do you know what offset and name brand triple clamps?
Where you able to just put your stock brake rotors on the 250f wheels and good to go? Is the pattern for the rear sprocket the same?
Thanks
gristle568
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11/8/2021 11:22am
djp48 wrote:
Nice bike. Do you know what offset and name brand triple clamps? Where you able to just put your stock brake rotors on the 250f wheels...
Nice bike.
Do you know what offset and name brand triple clamps?
Where you able to just put your stock brake rotors on the 250f wheels and good to go? Is the pattern for the rear sprocket the same?
Thanks
They were the scar racing clamps, I found them on eBay brand new for like $200. I actually have a stock set off a 2015 kx I was planning on using but the fork diameter was smaller on the 2011 forks and they wouldn’t work. I had the wheels complete so the rotors were already on them. Any wheel from 04-18 should bolt right up. You may need an adapter for a bigger rotor is all.
djp48
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11/9/2021 3:49am
DJV804 had mentioned keeping with the same years fork and clamp. Thanks for confirming that. Looks like some years interchange but it also looks as if clamps very even from the 450 to 250 for different year.
As far as I can tell you need to decide what fork your running, 250, 450 and year. Then make sure you are getting the clamp for that year and model fork?
Cool with the wheels. Something definitely to consider.
DJV804
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11/9/2021 5:27am
djp48 wrote:
Nice bike. Do you know what offset and name brand triple clamps? Where you able to just put your stock brake rotors on the 250f wheels...
Nice bike.
Do you know what offset and name brand triple clamps?
Where you able to just put your stock brake rotors on the 250f wheels and good to go? Is the pattern for the rear sprocket the same?
Thanks
Rear wheel is exactly the same 2003-2022, everything will interchange but I’d recommend sticking with a 125/250f 1.85” rim.

Front wheel the 99-05 kx125 has the old p/n, anything 4-stroke 06+ will bolt up but you’ll need the axle and wheel spacers from 06+ as well as a brake disc.

Oem rotor size was 250 I believe up through 2016 so you won’t need a caliper bracket unless you wanna do a larger rotor(which I would recommend anyway if you’re going through the trouble).

2019-2022 and 21-22 kxf front wheels won’t fit, unless you get that year of forks or have the lugs bored out. They have a larger diameter axle.
djp48
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11/11/2021 3:51am
Does any one know if the fork length or lug offset changed for the 2019 + Kxf forks?
How about the upper tube diameters? Just trying to figure out what may have changed as far as triple clamps go. Probably the same issue to address as far as the steering stop goes.
I understand the bore for the lugs has changed and I assume you would need to use the current front axle, spacers hub and possibly front brake mounting brackets.
What other issues might be foreseen?
DJV804
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11/11/2021 6:54am
2019+ Kx450 And 2021+ 250 clamps will not work. Steering stem length changed. Forks should work if you can find clamps with the right clamping diameter.

Imo if you’re gonna spend the money for that new of stuff just find some 2-3 years old a-kit forks. However Anything newer is a step up from the stock ones.

No matter the year, you don’t need caliper brackets, just corresponding axle and triple clamp. don’t overthink this. It’s really not that complicated and there’s probably 100+ threads on here how to do it if something hangs you up
11/12/2021 11:04am
For shock you must change this parts and 99 or 2000 kx shock be used.

My fork is à 2011 kxf, clamps for 2011 kxf ( wheels and brake ans wheels kx 250 )

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djp48
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11/13/2021 4:29pm Edited Date/Time 11/13/2021 4:52pm
Let the spending begin. 2019 kx 450 forks are on the way.
With a lot of research and help from members on this sight I believe I have a game plan.
It will be a while before I get parts gathered to make this happen but will try to update everyone interested on how the conversion goes.
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