Newbie fork Q.

[Mountainman650]

Hey guys
I read so much about the KX fork conversion.
I was wondering why/what exactly benefits are you getting
from this conversion ,are the KX forks just "beefier " to
take more abuse,or do they have more adjustability???

I have a '93 KDX 250, which has the USD, 43mm forks on them.
I 've read that the same year KDX 200 had the 41 mm., are the 43mm
the same as the 93 KX?? If so ,how well do these hold up, compared to the newer KX forks?

Was also wondering why Kawi switched to the current (non-USD),
forks? Problematic?, price?...
Sorry if this has been covered before . I'm fairly new to the KDX world
and ,just want to know more....This is such a fun bike , I wish I had bought one years ago.
Thanks
Dave in Pa.

[cmot]

Hi M.M. I dont have much input to give as your KDX250 is not covered much in KDX talk circles. But it should be interesting what kinda info you get from this post. I will keep an eye on it. I've allways wondered what the 250's are like.
I will check and see if youv'e posted any pics of your bike. Good luck

[Indawoods]

I changed mainly due to fork underhang. It put me down last year and about put me down several other times. Just plain got sick of it.

The newer USD's have both compression and rebound adjustments too. A plus for sure. They are stiffer and feel great.

I always wanted the KDX250 in my stable... someday I will get one.... Your forks should be fine as long as you get them sprung right for your riding style. I wouldn't change 'em if it was me.

[m0rie]

Internally the USD forks that are on your KDX250 are pretty much identical to the conventional forks that are on the 95+ KDX's. The only real advantage they offer over them is a bit less underhang and a bit less flex due to the design of the USD forks.

Modern USD forks are much more adjustable (rebound and compression like Inda mentioned) and as they tend to be larger (some bikes have 50mm forks!) flex much less, which helps when your spending a lot of time in the air, or taking a pounding on the trail. You could get a fairly nice boost to your existing forks by respringing them and tossing in some Racetech Gold Valve (cartridge valve replacements). Converting to KX forks will cost more than that but will offer more adjustments. Either way, your in a good place to start!

-Maurice

[skipro3]

Stock kdx forks flex so much I could acually see them deflect against the direction the wheel was pointing!!! Not Good!

Compression and rebound adjustment, more travel, less underhang, etc. make this a mod worth doing in my opinion

[canyncarvr]

Newer KX forks are 46mm (in the '98-'04 range I believe). May be the same on current models. I haven't gone to the trouble to look up current specs. The BuyKawi site has that info if you want to check a specific year. You have that?

Heck........
!CLICKY!

Note: This is NOT the front page of BuyKawi..but the info/parts lookup page.

RE: Why did Kawi switch the KDX setup?

I don't know. They didn't tell me. Don't know the why of that either.

I would be surprised if it was NOT a price issue.

I'm in the middle of the conversion (quite a long one, 'eh folks?). My reason is single..underhang. My oem KDX forks have been revavled by MX-Tech and sprung to suit by myself; they work just fine. Very well, actually.

Having not run USDs on this bike, I don't know to what extent flex is an issue that a set of KX forks will fix. I've seen many a USD bike's forks get real tweaked after relatively mild contact, my forks have never slipped a spec from where they are set in the clamps. With that in mind, I don't quite get how rigidity of a USD setup is much of a good thing.

Wouldn't be the first thing I didn't get that was still a fact.

'Newer' KX forks are known to have problems related to the bladder fork setup. General consensus by far is to defeat the bladder system cuz it stinks. My KX forks ('99 KX250) have already had it removed.

There is a product available that reduces stiction..Forkslyk or something like that. It's a topically applied slippery stuff. Skipro has used it.

Any USD setup is going to have a hard life in the woods. Fork guards and seal savers are probably a good idea.

[KDXGarage]

Mountainman650, all the people on this site that converted from KDX forks to KX forks went from the conventional forks (right side up, if you will) to USD forks. Out of the few of us that have stock KDX USD forks, I know of no one who has converted to KX forks. It seems most folks have reduction in underhang as one of their main reasons to convert from their conventional KDX forks to KX USD forks. Underhang is the part of the forks that goes below where the axle is. Some people have the underhang part to catch in ruts, which I can imagine would be no fun.

The 1991 - 1994 KDX250 had 43mm USD forks and the 1993 and 1994 KDX200's had 41mm USD forks. The 43mm and 41mm refers to the inner tube diameter. You have the best forks that ever came stock on a KDX released in the USA. The 1991 - 1994 KDX250 forks are all either exactly the same or close to it. The 1993 KX forks are definitely more advnaced than the KDX250 forks. Without boring you to tears with the technicalities of the differences, just let me sat that the '93 KX forks are more advanced in design and parts-wise.

My guess is that cost made Kawasaki switch back to conventional forks. They meet a price point before building a bike.

From your comments:

Sorry if this has been covered before . I'm fairly new to the KDX world
and ,just want to know more....This is such a fun bike , I wish I had bought one years ago.

If you are considering a KX fork swap, unless you have money burning a hole in your pocket, you may want to try to maximize what you currently have first.

I hope all this helps.



Just for the record, here are some KX fork facts.

Before 1988 = damping rod style, 1988 and on, cartridge style

conventional
1982, 41mm
1983 - 1987, 43mm
1988, 43mm
1989, 46mm

USD
1990, 41mm
1991 - 1995, 43mm
1996 - 2001, 46mm
2002 - 2005, 48mm

[skipro3]

Good chart Jason!

If you can find a buyer for your stock forks and wheel to offset the cost of conversion, the upgrade is comparable to KDX fork mods. Keep in mind if you require someone to tune the moto-x out of the KX forks to make them woods friendly, then it does get pricey.

My stock forks would point my bars and wheel in different directions every time I fell down. (often) and I would have to grab the front wheel between my knees and the bars in my hands to torque back. I don't know why they did this so easily, but with the KX set up, I've sent my bike, endoverend and flopping like a fish, snapping levers, bark busters, brake lines and throttle cables. The front wheel, bars and forks were never knocked out of alignment. It's strong and with the Scotts dampner, it will drive straight over just about anything the front tire can get a knob to grab hold of.

[KDXGarage]

For what it is worth, USD forks of "X"mm diameter are going to have less flex than conventional forks of the same diameter.

In my opinion. no need for a newbie to come up with hundreds of dollars to convert from USD forks to USD forks. If you feel you must have knobs to twist and click, buy an old radio from a thrift store.

skipro3, I think the idea is not to crash in the first place. JUST messin' with ya.

[skipro3]

My motto is: If you ain't crashin' then you ain't learnin'

It's made me a better skiier and I hope a better rider. I know it makes me hurt more!!!! But I love it!!!! Nothing like a good crash story to swap with your riding buddies. And they do seem to appreciate the entertainment value. Just ask FarmerJ, he got a front row seat at a crash of mine. I think he scored me an 8 out of a possible 10. Would have been more, but I only rolled twice.

[KDXer]

Would have been more, but I only rolled twice.

AND it wasn't caught on camera for us to laugh at !!!

[Mountainman650]

Hey guys
Thanks for all the great responses, I was mainly just curious.
I plan on sticking with my stock ones .I haven't even gotten in much riding time on the KDX yet. Shortly after I got it , I took the forks off to have the seals replaced and just got her back together after a three week "down time".
Plus I've been busy with some dual sport rides on my DR 650. I wish I could get the KDX street legal in Pa., it would be a blast on some of these tight rocky trails
that the big DR is hitting.I like the DR but it does wear you out alot quicker wrestling that heavy bike around the trails all day long.Which is why I got me a KDX
Catch ya later
Dave in Pa.

[KDXGarage]

You're welcome. If you ever need any suggestions on improving the stock forks, ask away.

I have a friend with a DR650, and he is wanting a KDX.