Front Suspension on 91' KDX 200

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#1
I just recently bought a 91 KDX200. I have slowly but surely been trying to get this bike back into shape. I have been told by numerous people that the front suspension is very soft, and I have been noticing this because I seem to be spending a lot of time on the ground. I am sure that the springs are not rated for my weight that is between 185-190lbs. I need advice on some options of what I can do to make this better. I read Jeff's recommedations on the .35kg springs, but I have also been told to change the front suspension out with a KX250 forks. If this is an option then what year do I need to get, and will the old front tire assembly fit? Can I just put new suspension in its place without mods? Any advice would be greatly appreciated, obviously I need help.
Thanks
 

dirt bike dave

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#2
On my '90, Race Tech cartridge fork emulators and stiffer springs made a huge improvement.

The stock fork has way too soft a spring and too much high speed compression damping. The springs kill you on big jumps and whoops, while the excess high speed compression damping makes rocks and roots a problem.

I think around 0.38 to 0.40 kg/mm springs would work well for you.

A free alternative is to cut a few coils off your stock springs. This will stiffen them up some, but you will need to add some pre-load spacers.

IMO, it's hard to justify spending alot of money and time on a '91 KDX, as you could put that toward a newer bike instead.

However, the forks are the weak link on the bike. If you do nothing else, stiffen the springs.
 
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#3
To swap out the front end you will want to start with a '96 and up front end. Make sure you get forks, triple clamps, front wheel, front brake caliper w/mounting bracket. You need to have the KDX stem removed from your stock lower triple and pressed into the lower triple of the KX forks. If you want to keep the headlight you have to do some mods but other than that it really is quite simple to accomplish. Hey, if I can do it I'm sure you can!

BTW, if you really want to do a front end conversion, go here (http://kdxrider.net/forums/) for a more in depth explanation. Just scroll down and you will see there is a complete subforum just on doing fork conversions.


dirt bike dave said:
IMO, it's hard to justify spending alot of money and time on a '91 KDX, as you could put that toward a newer bike instead.
I have to respectfully disagree. If the KDX is just your type of bike then it is worth it IMO.

I have a '90 and love it. The power delivery is spot on for my riding style and I like the ergonomics of it better than the newer machines. I'm just finishing up a front end conversion using '96 KX125 parts. It should hopefully been done in about a week. I also plan to rebuild the engine (upper and lower) later this summer and rebuild the rear suspension as well. When I get it all done I will have a better than new bike for under $2k and that is inculding the purchase price. Is it all worth it? IMO, yes! :cool:
 
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#4
IMO, it's hard to justify spending alot of money and time on a '91 KDX, as you could put that toward a newer bike instead.
I'll also disagree, however, not respectfully! lol!

The E series KDX engine is legendary. It's hard to find a better woods engine. With some suspension work and a few mods, many riders on much newer machines will spend the majority of the time looking up your rear fender. Great bikes! My 89 is easily the most reliable, comfortable, and versatile bike I have ever ridden. I have under $2,000 total in the bike as it sits.

Stiffer springs and emulators are a good step. A KX fork swap is arguably the best mod. You can use any year KX 125/250 fork, but you will need the entire front end. You have to press the stem out of the lower KDX triple and press it into the KX lower triple, then bolt the front end on the bike.

I put YZ250 forks on mine, pretty much the same routine. There's an entire section on front end conversions over at kdxriders.net. You'll have to register to get access to the forums there.
 

dirt bike dave

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#5
I've got no problems with KDX's and appreciate the enthusiasm. It's a nice trail bike, but let's keep it real.

In 34+ years of riding, I've owned three ('84, '90 and a '91 KDX250) and my buddies have also owned many, including an '89. I've got many hours of seat time on these bikes and other KDXs, including a KX/KDX hybrid.

IMO, it just does not make much sense to spend a few hundred dollars + time finding and installing forks on a 20 year old trail bike that will be worth <$1,000 when you are done.

Most riders would be better off fixing the forks on the cheap, ride it a few years, sell it for what you can get and move on.

Hard to find a better woods engine than a KDX 200? Really? I've ridden many bikes with much better woods engines, IMO.

No way would I recommend someone get into a '89 KDX for $2,000 + lots of their own labor.

There are $2,000 bikes out there that have way more motor and suspension than an E series KDX200. Lots of 'em handle great, have superior brakes, are reliable and comfortable, too.

But to each his own.
 
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#6
Hard to find a better woods engine than a KDX 200? Really? I've ridden many bikes with much better woods engines, IMO.

What, a four stroke? Blah! You can keep it. The only comparable bike I can think of would be a 200 XC. Try finding one of those in decent shape for what you can find a rebuild a KDX for. Good luck! I haven't added it all up, but I'd say I have around $1500 in my bike, and that's including new tires and every other little bit and piece including purchase price.

I have plenty of seat time on my buddies 200EXC, and while it's a great bike, I honestly prefer the comfort and tractability of my KDX. It's all about what works for you personally, right? The KDX works well for me. I have several friends riding 450's these days, and they don't stand a chance on the single track. It never fails to piss them off, which always makes me smile.

FWIW the KDX250 is a fat pig compared to a 200, even an old E series 200, so that's not much of a comparison. Great engine on the 250 though!

Telling a KDX owner not to waste any money on an "old bike", would sorta be like telling a Maico fan not to bother wasting time and money on that old 490. It just doesn't work ;)
 
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#7
julien_d said:
Telling a KDX owner not to waste any money on an "old bike", would sorta be like telling a Maico fan not to bother wasting time and money on that old 490. It just doesn't work ;)
Had bought an 86 brand new, sold it a few years ago and got an 03 220. Still have the 03 and found my old 86, then bought that back. Found another 86 for next to nothing and bought that too. Will fix it all up just like my other 86. :cool:
 

Joburble

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#9
It's not always about the money, sometimes it's just about building the bike you want, they are just two different philosophies.

Spend what you want on your bike, nothing more, nothing less. If you spend a lot on it just make sure you use it lots to make it worth it, and congrats dfanning on buying a KDX.

Spending a lot of time on the ground may not just be a fork issue, as in fix the forks and you will stay upright. There is a whole lot of bike setup you may want to try before you spend any money at all.
 
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#10
This is true. Sag is very important, and play with your clickers too. If the front end is washing, you can try raising the forks in the clamps just a hair..
 

dirt bike dave

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#11
FWIW, a steering damper is a great mod for a KDX, and can be transferred to your next bike.

The first damper I ever had was a WER on my '90. It changed a lot of crashes and front end washouts into near-crashes.
 

dirt bike dave

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#12
FWIW, here is the kind of used bike deal that would keep me from spending several C notes on a fork swap to a 20 year old KDX200.

http://www.dirtrider.net/forums3/showthread.php?t=177765&page=1&pp=20

Tricked out '03 RM265 set up for woods, ported for low end, and has the suspension already done. Asking $1,700 or a little more if you want the Rekluse clutch, spare wheels, spare pipe, etc..
 
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#13
It's a nice bike, I'd like to have it myself. But if a KDX is your thing, that RM is not gonna do it for ya.

I get where you're coming from Dave. But as I'm sure you know, you're posting in the "JUST KDX" forum. Most of us are here because we like KDX's, and are looking for ways to repair, upgrade, or modify them. NOT because we're looking for what you think is a "better bike". You might as well go in a vintage forum and tell them they're all stupid for liking an early 80's Maico 490 and see how that goes over. I don't care who you are, coming into an exclusive KDX forum and telling people their bike isn't worth spending money on is asinine.

Now If someone want's to hand me that RM for less than I spent on my fork swap ($65, btw), then I'll take it, but I seriously doubt it could replace my KDX. I can only think of a couple bikes that might do that, and either one of them would cost me an assload.
 
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#14
Very well put, Julien. :cool:
 

dirt bike dave

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#15
Defensive much?

You are reading waaaaaay more into my posts than is actually there.

BTW, after owning KDX's from 1984 - 2001, I think I'm entitled to an opnion on fork swaps, just as you are entitled to your opinion that the KDX250 is a fat pig.

FWIW, many of the set up tips that have been regurgitated on this site for the last 10+ years for the KDX250 were developed through trial and error by myself and my friend, another long time KDX owner. So it's not like I just come in here and bash, lol.

My opinion is most riders are better off saving the cost and effort of a fork swap. Clearly, you are not most riders, as most still have their stock forks and are not savvy enough to complete a swap for $65. Kudos to you.

BTW, I've ridden early '80's Maico 490's and have very fond memories of those bikes. So you are not going to find me insulting them in the vintage forum in anyway near the manner you have insulted all those fat pig KDX250 owners, lol.