Showa SFF TAC forks on a 04+ KX125?

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12/5/2017 6:31 PM

Howdy folks. What would it take to fit the Showa SFF TAC forks off my '15 Kx450 to a 04+ KX 125? Would i be able to just swap the whole front end over? Do I need to swap the steering stem?

Thinking about getting kit forks for my '15 KX450 and would like to keep and use the TAC forks for the pinger.

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12/5/2017 8:55 PM

You're gonna have to take a lot of shims out, but I bet the 3lbs lighter front end can only be a good thing on a 125

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12/6/2017 7:00 AM

theycallmeebryan wrote:

Howdy folks. What would it take to fit the Showa SFF TAC forks off my '15 Kx450 to a 04+ KX 125? Would i be able to just swap the whole front end over? Do I need to swap the steering stem?

Thinking about getting kit forks for my '15 KX450 and would like to keep and use the TAC forks for the pinger.

You'll need triple clamps, axle, wheel, spacers, front brake assy, and the forks themselves.

Valving and pressures will be much different.

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12/6/2017 7:40 AM

That's all fine as i'd be pulling it all off my 450. Will the 450 triple clamp bolt up without any modification needed? In theory, could i just swap the whole front end over from my 450?

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12/6/2017 8:24 AM

Measure the stems, you may need to swap them, if possible. I think air forks are awesome on a 2t bike. I would not valve right out of the gate, rather the psi adjustments will be much lower, and throttle will be in the "fuckyea" position more often.

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Livin' the dream, two wheels at a time!

12/6/2017 8:46 AM

Stems will not have to be changed. The hardest part will be welding on a new steering stop. I give a descent step by step in my build thread, found here:
http://www.vitalmx.com/forums/Bike-Builds,46/2003-KX-125-Old-School-Build,1328902

Another example here
http://www.vitalmx.com/forums/Bike-Builds,46/05-KX250-Rebuild-and-Upgrade,1318556

Front brakes do not need to be swapped. I believe your '04 has the "CR style" front brake line routing, so you will not need a new line. You will need a front axle and wheel spacers from a new four stroke. Your 125 front wheel will work.

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Tomac and/or Anderson for 2020.....

12/6/2017 10:22 AM

BobPA wrote:

Stems will not have to be changed. The hardest part will be welding on a new steering stop. I give a descent step by step in my build thread, found here:
http://www.vitalmx.com/forums/Bike-Builds,46/2003-KX-125-Old-School-Build,1328902

Another example here
http://www.vitalmx.com/forums/Bike-Builds,46/05-KX250-Rebuild-and-Upgrade,1318556

Front brakes do not need to be swapped. I believe your '04 has the "CR style" front brake line routing, so you will not need a new line. You will need a front axle and wheel spacers from a new four stroke. Your 125 front wheel will work.

Thanks a ton, Bob!!! That's exactly what i was looking for.

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12/6/2017 11:46 PM

So i just did some measurements on my 450 and the 125.

On the '15 KX450f:
-Fork OD at bottom clamp : 59.XX mm
-Fork OD at top clamp : 53.XX mm

On the '04 KX125
-Fork OD at bottom clamp: 59.XX mm
-Fork OD at top clamp: 55.XX mm

Wondering if i can just swap the top clamp of the '15 Kx450 over to the stock '04 KX125 clamp and be fine? pretty sure the forks are the same distance apart on both bikes.

Might be too easy. Anyone try that?

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12/6/2017 11:55 PM

Worth a try dude

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12/7/2017 12:30 AM

I think it may work. I just saw this picture on ebay which appears to show a 04+ KX 125/250 lower clamp, stock '15 KX450 upper clamp with Showa SFF TAC forks mounted.

Photo

I'll try it out tomorrow after work.

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12/7/2017 9:05 AM

I just tried this the other day it won't work. You have to remember the difference in offsets, you can get one fork in but the other will not.Photo

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12/7/2017 11:37 AM

Damn, way to rain on my parade DB97! Haha. Thanks for the heads up, and for saving me an hour this afternoon trying it.

Is the offset of the KX250 clamp the same as the KX125? Perhaps a KX250 clamp has the same offset as the KX450f?

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12/7/2017 11:51 AM

The part numbers for the KX125 and KX250 lower clamp are the same. Wondering if that picture above is showing a 1st generation KX250F lower clamp, which looks similar but has a different part number.

Wish all of the offset and diameter information was published somewhere for quick cross referencing and parts compatibility.

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12/7/2017 11:55 AM

No problem. I'm doing the same thing right now leaning towards a shim so I don't have to modify anything. Photo

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12/7/2017 12:41 PM

From what i gather, here are the stock offsets:

13+ KX450F : 23mm
03-05 KX 125/250: 25mm

The next closest i can find is a 09-10 stock lower clamp (23.5mm offset), but the steering stop posts are not the same style as the 03-05 KX so its the same situation as the stock '15 450 clamps.

Not looking good unless we can find an aftermarket lower triple clamp that's a 23mm offset, has the same steering stop posts as the stock 03+ KX lower clamp, and accepts a 59mm OD fork.

I was also thinking of contacting that ebay seller and asking what lower clamp that is.

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12/7/2017 12:49 PM

One other possibility. Why not just drill and tap into the stock lower KX450 clamp and add a bolt there that will butt up against the stock KX125 steering stay? Crude drawing below. The red obviously being the bolts added.

Photo

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12/7/2017 12:54 PM

Here's my pinger that i'm trying to do this on smile

Photo

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12/7/2017 12:55 PM

I thought about that too but I think you would want to use billet clamps instead of cast would be stronger. I found these pictures last week of stops like you described. Photo

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12/7/2017 12:58 PM

theycallmeebryan wrote:

Here's my pinger that i'm trying to do this on smile

Photo

Nice man looks good. Mine is in a million pieces still lol

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12/7/2017 2:01 PM

So i contacted the ebay seller and they are telling me it came off a 2004 KX250. DB97 what year bike do you have? Maybe the offsets of the 250 clamps are different than the 125?

Photo

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12/7/2017 2:15 PM

I have a 05 kx125 and I was using 16 kx450 clamps and forks. It's really close and you could force it but it's not right definitely putting pressure on the tubes.

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12/7/2017 3:19 PM
Edited Date/Time: 12/7/2017 3:20 PM

Do the kit forks require a new set of clamps?

Are you able to use the stock 2015 clamps as a whole set of triple clamps? If so, just remedy the steering stop issue and ride on.

An option is: Make a new steering stop for the frame and have it welded on.

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12/7/2017 3:38 PM

I'm trying to avoid having to do any fabrication that will prevent me from going back to stock.

Changing the stock steering stop on the KX125 frame means that i wont be able to use the stock clamps ever again.

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12/7/2017 4:07 PM

Same here and I powder coated my frame already before I found out the stock forks were hurting. Another thing is from what I've read the 125 has good handling in stock form I really didn't want to affect it by using different offset clamps.

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1/6/2018 1:46 PM

My buddy finally had the time to make the spacers. Works great and zero modifying of frame and I keep stock clamps. Photo

Photo

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1/28/2018 3:34 PM
Edited Date/Time: 1/28/2018 3:34 PM

DB97, any chance your buddy would make an extra set? I'd be interested.

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1/28/2018 3:47 PM

theycallmeebryan wrote:

DB97, any chance your buddy would make an extra set? I'd be interested.

He's a machinist so I'm sure he will, I'll ask him this week.

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11/5/2018 4:24 PM

Ehi! Going back to this post cause I’m doing the same thing but with the Showa 49 of a CRF 250 2017!
DB97 do you confirm me that you are using fork with Stock clamps just adding that spaces? ? please tell me yes ??

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11/5/2018 4:42 PM

SteGallo4 wrote:

Ehi! Going back to this post cause I’m doing the same thing but with the Showa 49 of a CRF 250 2017!
DB97 do you confirm me that you are using fork with Stock clamps just adding that spaces? ? please tell me yes ??

Yes I'm using kx 125 clamps (PC now) with kxf forks. Photo

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5/10/2020 9:02 PM
Edited Date/Time: 5/10/2020 9:03 PM

BobPA wrote:

Stems will not have to be changed. The hardest part will be welding on a new steering stop. I give a descent step by step in my build thread, found here:
http://www.vitalmx.com/forums/Bike-Builds,46/2003-KX-125-Old-School-Build,1328902

Another example here
http://www.vitalmx.com/forums/Bike-Builds,46/05-KX250-Rebuild-and-Upgrade,1318556

Front brakes do not need to be swapped. I believe your '04 has the "CR style" front brake line routing, so you will not need a new line. You will need a front axle and wheel spacers from a new four stroke. Your 125 front wheel will work.

Bob, blowing he dust off this one for a question: what is the easiest ways to get CRF routing on a 2000 KX fork? I have to buy a line and fork guards already FYI.

Also, do you know the stock offset on the 2000 KX?

BP

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