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2001 KX125 forks

Posted: 10:45 pm Jul 20 2018
by morganid
I never thought I'd be doing a fork swap. But here I am. (My bike: 2003 KDX 220)

I bought a 2001 KX125 roll-well, dragging chassis. I call it a dragging chassis because I don't have any rims. Here is what I do have.

Frame
Sub Frame
Swing Arm
Most of the suspension linkage (no rear shock)
Forks
Tripple clamps
Front and rear axels
Front and rear hubs (no rims)
Front caliper and brake line. (No lever or perch)
Clutch cable
Ignition system and wires

Q1: I thought I read that the triple clamps will work IF the KDX stem is pressed into the KX triple clamp. Is that true? In my research, I found a thread where someone just machined a bushing to take up the extra room above the frame, under the top triple clamp. I assume they are using the KX steering stem.

Q2 If I use the KDX stem, the bearings should be OEM size bearings, right?

Q3. Will ANY rim work with the KX hub? I assume it's the hub that makes a wheel compatible/incompatible with a set of forks. I have the KX hub, but not a rim/spokes.

Anything else I should be aware of when doing this swap?

Re: 2001 KX125 forks

Posted: 11:09 pm Jul 20 2018
by KDXGarage
One cannot use the KX stem, as it is thicker and won't for the KDX bearings.

I would suggest the KX run for the KX hub.

Re: 2001 KX125 forks

Posted: 11:48 pm Jul 20 2018
by morganid
Do you know if the KDX stem will press into the KX clamp?

Re: 2001 KX125 forks

Posted: 06:54 am Jul 21 2018
by KDXGarage
I think the diameters are the same, but I can't guarantee it. I remember using 0.025 " shim stock inside the KX upper clamp hole to take up the difference on that area.

There are a ton of threads on here to read through, though.

Re: 2001 KX125 forks

Posted: 12:33 pm Jul 21 2018
by tropicoz
morganid wrote:Do you know if the KDX stem will press into the KX clamp?
When I did a fork swap, mine pressed in perfectly without an issue. Some others have had to knurl the stem to get a tight fit.

Re: 2001 KX125 forks

Posted: 01:03 pm Jul 21 2018
by morganid
What year of kx tripple clamps did you use?

Re: 2001 KX125 forks

Posted: 05:45 pm Jul 21 2018
by tropicoz
morganid wrote:What year of kx tripple clamps did you use?
I used a complete front end from a 2003 KX125

Re: 2001 KX125 forks

Posted: 07:51 pm Jul 21 2018
by bufftester
IIRC: Q1: you can press the KDX stem into the KX triple, as mentioned somehave had to knurl it, others haven't. The bushing you read about actually takes up the slack in the KX upper triple clamp as the KDX stem has a smaller diameter than the KX stem. Also as mentioned, lots of threads on here about that including one I saw that had the measurements of the bushing.

Q2: If you use the KDX stem then use KDX bearings

Q3: You can use any 21" rim with the KX hub, just have to get spokes and lace it up. Easier is to find a KX front rim of the right years. The KDX front brake will work on the KX forks (that's what I used on my 2001 KX hybrid). I have also seen people use the KDX wheel with custom spacers (I believe RB sells them on his site)

Re: 2001 KX125 forks

Posted: 09:23 pm Jul 21 2018
by morganid
Thanks for the help guys. I'll do some more digging through the threads. Since my last post, I found a guy selling 2000 KX250 rims with no hubs. :supz: He wants $50 each. He said he'd sell me the front rim, tube, and use tire for $40. I'm tempted to buy the rear rim/tube/tire also but I don't really have a need for another rear wheel. The rear rim he is selling is a 19" and I have the stock 18" on my bike. If I do buy it, I'll need to buy a second set of spokes. Spokes are friggin expensive. RMATVMC has a set for $70 ish. That'd be $140 for front and rear spokes. In an ideal world, I'd like a second set of rims for street slicks. Then I'd need to buy a whole other wheel so I have 2 KX fronts and 2 KX rears. Boy this adds up fast.

Re: 2001 KX125 forks

Posted: 04:10 am Jul 22 2018
by doakley
Yes, you press the kdx stem into the lower kx clamp and you’ll have to shim the upper clamp. Use kdx bearings.
Much cheaper to just go on eBay and buy an entire kx front wheel assembly. I found mine with brake disc for $50.uour kdx caliper will work fine but not your kdx disc.

Re: 2001 KX125 forks

Posted: 09:59 am Jul 22 2018
by morganid
I have both the KX and KDX Caliper. Is the KX any better than the KDX? I realize both will work, just wondering if one is better.

Re: 2001 KX125 forks

Posted: 09:22 pm Aug 04 2018
by 6 Riders
morganid wrote:I have both the KX and KDX Caliper. Is the KX any better than the KDX? I realize both will work, just wondering if one is better.
IIRC the kdx caliper is better, but the kx master cylinder is better. I'm using a kx master, with a kdx caliper and my brakes are pretty solid. Whichever you decide to use, rebuilding is more important than which models part you use.

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Re: 2001 KX125 forks

Posted: 10:06 pm Aug 12 2018
by morganid
So. Why do you say the KX master is better than the KDX? I thought the caliper would be the part that makes one better than another. Does it matter which line I use?

Re: 2001 KX125 forks

Posted: 10:46 pm Aug 12 2018
by 6 Riders
I don't remember where I read that the KDX caliper is better, and I'm not sure it makes sense, since they are the same P#. As far as the master cylinder, I've always had better feeling brakes using the kx masters.
Brake lines are mostly preference imo. There are some set ups that you HAVE to use one or the other, but not many. Once you figure out which brake line works the best, consider replacing it with a new one.

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Re: 2001 KX125 forks

Posted: 11:18 am Aug 13 2018
by morganid
Ok. Thanks.

Well, I've been slowly aquiring parts as money and time permits. I'll start posting my progress soon.

2001 KX125 forks

Posted: 12:18 pm Aug 19 2018
by Malibu406
I just did this coversion and posted it a couple days ago. Be careful in buying parts. Relacing wheels and ensuring rims are good can lead to blowing money. I referenced the online part fiscs everytime i made a purchase to make sure of interchange. There is no reason to use the kdx hub and a kx rim, then you would still need the rb axle. Kx wheels through many years are the same, it is the axle that must mAtch your forks. I used a 94 wheel and 01 axle for 01 forks. I got an excellent wheel for $40. The kdx stem presses right into 01 triplepresses right in to 01 triples. Best modify the stem like i did or rb does and the rb spacer is nicer than using shim stock and old kx nut as a spacer, but by all means you can. If you buy and make some stuff yourself you can do the basic swap for $150.

Re: 2001 KX125 forks

Posted: 12:30 pm Aug 19 2018
by Malibu406
Oh, remember saving money on ebay is all about the research you do to find what years interchange. If you only focus on the year of your forks, yes it will fit, but you are greatly limiting yourself only to those auctions. Also dont believe what the posting says, get part numbers or dimensions. I had to retirn a set of 96 kx500 forks that were listed as 97, i wanted 46mm not 43. Thats when i learned to ask for dimensions. And that kept me from buying other parts listed wrong. These were all honest mistakes that happen when guys have thousands of parts from hundreds of bikes. Mistakes are made.

Re: 2001 KX125 forks

Posted: 01:49 pm Aug 19 2018
by morganid
Thanks for the heads up. I saw your post. The forks came with a KX hub. I bought some rims (no hub) from a guy on the local classifieds. The rims happen to be off an 02 kx 250. I laced it up and dropped it off at a shop to get it trued up. If I had more time, I'd try to true it myself. But right now that's not an option. But I'm getting charged $85 an hour to true it... The next wheel I lace I might make the time to true it... We will see how much the final cost is.

I bought the RB spacer, but the next step is to figure out the bearings. The info is out there, I just haven't taken the time to research it yet. I'm working 40 hrs on Swing Shift and have 3 kids that wake up between 7 and 8 am no matter what time I go to bed. :shock: I'm steadilly making progress, but it'll be slow as time/money is available. (Oh and I'm back in school I n 2 weeks....)

2001 KX125 forks

Posted: 02:04 pm Aug 19 2018
by Malibu406
Know the deal got 3 kids too. I reused the kx lower bearing. It is same bearing number as kdx. Then i reused top kdx bearing. I try to get stuff so i never go to a shop, like truing the wheel. I just waited until i saw on for sale the had a spin test video.

Re: 2001 KX125 forks

Posted: 02:34 pm Aug 19 2018
by morganid
What kind of handlebars are you using? The triple clamps I have did not come with the top pieces to clamp the handlebars. I am thinking about going with fat bars. I'm wondering if it will put the bars too high with the height from the adapter for the bars and the height from the KX forks/t. clamps.