Trying to get my nerve up . . . . . fork swap :)

[ihatefalling]

ALERT ALERT - fork conversion questions coming up

Hope everyone's been doing good.

I've been riding a ton of DS this summer but am lookng forward to getting back in the woods on the KDX.

Been reading up on the conversion. This is what I think I know:

Basically, pick the year KX / KXF forks & triple you want based on thier size. Bigger size is stiffer ride.

Send triples to RB, get stems swapped, get his axle / spacer kit.

Mount it all up. My KDX wheel and caliper will work. Figure out brake line and odometer cable routing. Go ride.

Am I right so far?

Then comes the part where I get really lost......don't know crap about valving and springs. I weigh 150 without gear. I ride rocks and roots. Ride hte bike as fast as it will allow with OEM forks, gold valves, 10wt oil.

I'm just spooked about the valving / springs. WOuld like to undertake the project and do all the work and get it right the first time.

Not afraid to buy newer forks if they make that much difference.

I know the pros get tired of babysitting. Do you mind helping IHF out? Feel free to let the wisdom flow

[scheckaet]

Send triples to RB, get stems swapped, get his axle / spacer kit.
I don't think he does the axle anymore, too much variation from fork to fork.

[gsa102]

I have been doing lots of digging on the same idea, trying to find the best woods forks to bolt on, since I play at racing HS. Some riders feel that conventional forks are better that any USD fork in the woods. One guy put the 87 CR forks on his 07 WR450, they are supposed to be that good. The 06+ YZ SSS forks are supposed to be awesome, if you can get them.

These are the ones that I have found some consensus on for being good for woods:

87 CR 250, 43MM conv., should fit the KDX triples, but lots of underhang.

91-97 WR/YZ 250, 43 mm USD

96-98 RM 250, 49mm conv.

07-09 CR250X, 47 mm USD

I am sure there are guys on here that have found others that work well, just not a lot of agreement on which ones are THE FORKS to get.

Check the race tech website or FRP for suggested spring rates for your weight.

[osobad]

just about any kx fork can be made to work well in the woods if revalved by competent suspension tuner and will be easier to do . Easy way is to get 99-03 kx forks and tripple, and front wheel with axle. This way you can use your same brake caliper from the kdx. you can then get the RB spacer for the top clamp and your done. Huge improvment over stock. Since you are on the light side look for kx 125 as they are the same fork but sprung lighter most of the time. When you send the tripples to RB get the spacer at the same time. I pressed my stem out and then had it knurled and pressed it in the kx lower myself.

[marrk_us]

"just about any kx fork can be made to work well in the woods if revalved by competent suspension tuner"

+!! I agree with osobad 100%.

And a "competent suspension tuner" does not mean "my buddy who once changed his fork oil and has many shiney hammers". And the whole upside down vs. conventional fork debate seems way overblown. I've converted a few kdx's to usd forks and haven't had problems with seal leakage, but i've always installed new seals and bushings before having them revalved and installed, and changed the fluid often, not just when they start leaking. But i'd also rather have properly set up conventional forks then mx valved USD's.

Just go for a set of cartridge type forks (USD or RSU), preferably adjustable for both compression and rebound. Replace the seals and bushings, then have a suspension specialist respring and revalve them for you, your weight, terrain, and ability and you'll be set.

Expect to drop a little money ($400-1000) but it'll be the best money you spend on your bike. Too many times it seems everyone is willing to spend thousands on a bike, wheels, pipes, decals, etc. but they won't spend any on their forks or shocks. Maybe because it's not blingy or doesn't shine. But i'd rather have properly set up suspension then bling.

[rbates9]

just about any kx fork can be made to work well in the woods if revalved by competent suspension tuner and will be easier to do . Easy way is to get 99-03 kx forks and tripple, and front wheel with axle. This way you can use your same brake caliper from the kdx. you can then get the RB spacer for the top clamp and your done. Huge improvment over stock. Since you are on the light side look for kx 125 as they are the same fork but sprung lighter most of the time. When you send the tripples to RB get the spacer at the same time. I pressed my stem out and then had it knurled and pressed it in the kx lower myself.

+.75

I'm not sure the 03 would accept the KDX brake but like I said I'm not sure.

Yes due to your weight you should look for 125 forks for the lighter spring rate. But if the forks have been "Done" you will have to find out what has been done to them for springs.

I think if you go with 99-01? forks RB might still do the axle mod for you but you might want to give him a call before you buy something just to make sure.

Check you local want ads for blown up or parts bikes that are complete and you might find a great deal on a complete bike so you should have everything you could need and sell the rest of the parts and you might get a free fork swap!

I used 00 KX forks on my 00 KDX and no knurling was required but you will have to turn down the upper portion of the lower triple area on the stem so the bearing will sit flush to the lower triple.

The newer the better, but by how much is debatable. Anything newer than 96ish for KX forks will be an improvement. It kinda boils down to how much you want to spend and what shape the forks are in.

For the most part the KX forks are a great improvement with few draw backs. Go for it!

[osobad]

I have 2003 forks on my kdx right now. stock kdx brake caliper and rotor(96) kdx.fits perfect. pro action revalved forks for 225.00. seals springs and bushings are a little extra. they do not just re shim, they use a different piston depending on wich type of riding you do. I have them working on a showa rear shock right now for the back.

[ihatefalling]

Thanks for the feedback guys.

I bought my bike (05) used and I'm pretty sure the guy put new springs in it. Gold valves and 10wt oil. SO it handles about as good as I guess it can.

I can still feel the spaghetti legs in the rough stuff and on kickers and the underhang has jabbed me a few times.

I want/need to be faster in the woods, but realize I just can't be any faster on my current front end, plus I think it can be dangerous at times.

I thought about going orange or a gasser, but just can't let my KDX go. Everything about it is good.....except for the dang fork flex.

I'm going to keep my eyes open local/ebay for some forks. I would rather drop a grand on the KDX than sell it and drop 4-5 grnd on a used KTM that will soon start leaking everywhere. I'm going to look for those 125 forks like ya'll said.

[osobad]

if you look you will be able to find good forks and triple trees for around 150.00 to175.00. and front wheel and axle for 50.00 to 75.00 just be pacient. even befor you have it revalved it will work better than what you have at speed. you will be able to ride much harder into the corners also

[rbates9]

For the type of riding I do I just removed the bladders from the forks I bought and they work very well. Valving might not be needed right away depending on what and how you ride.

[SS109]

I weigh right at 150, 170 with gear. I am running .41's in my '96 KX forks. They are perfect spring rate for aggressive riding but a little stiff when just putting around.

The MX valving was way too harsh for trail use IMO. I had them re-valved by Donny at ZR1 Suspension and it totally changed how they feel, and how hard I can ride, for the better. Getting your forks re-valved by a reputable suspension guy is worth every penny.

[heckler]

if you can turn a wrench, you can revalve.

but get the right springs first.

http://www.thumpertalk.com/forum/showth ... p?t=991787

I paid $200 for 06 KX450 forks and $100 for the wheel. Just wait long enough and you'll have money left over for new springs and maybe even someone to revalve it.

I still don't know if the revalving was absolutely needed, but the softer springs were a definite must.

I'm so happy I did it. It took a while to get everything sorted out and running right, but it was well worth it.

[ihatefalling]

Still looking for the forks.

Have seen a few on ebay but for some reason keep second guessing if I should get them.

Not finding much on craigslist.

Do I remember that the front end will ride high with new forks? Am I going to have to run bar risers so I can raise the forks in the top triple?

Also, will my H front caliper mount up to the KX forks?

I wish one of you knowlegdable fork swap guys lived down the street from me :)

[fuzzy]

91-97 WR/YZ 250, 43 mm USD

These are in fact quite good. The YZ/WR forks are valved the same I think. They suck stock in the woods, but are fantastic at speed. I have two sets. Once stock, and one pro-action valved set for the woods(scored the forks and shock revavled, and sprung for 220# off ebay!).

96-98 RM 250, 49mm conv.

I rode a RMX w/ these a while back, and they were the best forks I've ever felt. Search showa on here, and you'll see where someone swapped in a set of these big older conv showas and loved them.

[gsa102]

After a ton of research, I settled on the 49MM Showa Conventionals off a DRZ400. They are the same fork as the 96-98 RM 250, but with a bigger valve for Off-road. I may actually have to go with a lighter spring when done. On the way to what the KDX should have had stock. Now just need to find me a Showa Shock...

[ihatefalling]

I've got an '01 DRZ with conventionals up front and it hand;es better than my OEM KDX forks with springs and valves put it.

[ihatefalling]

OK guys, so I weight 150ish, looks like from the racetech spring calculator I should be OK with a set of 99-01 KX125 forks. SPring-wise I should be OK

Plus, RB still does the axle for that year range so I can use my KDX front wheel.

Question about valving..... From the sounds of it these KX forks will need to be revalved for the woods. When ya'll talk about revalving, are you talking about just getting some gold valves from racetech? (vs sending the forks off to a tuner)

The used forks I buy will probably need bushings and seals, so I could go ahead and put the valves in then.

[rbates9]

If you go with those forks it might be worth your time to read this http://www.thumpertalk.com/forum/showth ... g+bladders

I did it to mine and have been pretty happy with them. I'm sure they could be better but they work good for me.

[Tedh98]

Definitely disable the bladders if your forks have them.

This is only from what I've read - the biggest advantage to buying gold valves is that you get a chart with a series of stacks. So if you don't like what you start with, you've got a number of stacks that are firmer or softer and you know exactly what set of shims to combine.

But I'd hold off on spending the $170 for GV and try revalving yourself. There is a lot of revlave threads for those forks, so you wouldn't be starting from scratch.

[Julien D]

91-97 WR/YZ 250, 43 mm USD

These are in fact quite good. The YZ/WR forks are valved the same I think. They suck stock in the woods, but are fantastic at speed. I have two sets. Once stock, and one pro-action valved set for the woods(scored the forks and shock revavled, and sprung for 220# off ebay!).

96-98 RM 250, 49mm conv.

I rode a RMX w/ these a while back, and they were the best forks I've ever felt. Search showa on here, and you'll see where someone swapped in a set of these big older conv showas and loved them.

I defintely concur on both points. Those RM conventionals were some of the best feeling forks I ever experienced. Likewise, the 43mm YZ250 forks I am currently using are awesome when I'm hauling ass, but in the single track they beat me up pretty bad. I've been wanting to re-valve them for quite some time, but never got to it.