!998 220 with KX upside down forks..

[NoBs]

Considering purchasing a 1998 220 that supposidly is in great shape but with the KX upside down forks. Is this a upgrade, downgrade or just a sideways issue ? The originals are not availble. Anyone know what the difference would be in tight single track or any riding conditions really.... older rider that occasionally goes too fast for his age asking questions.. any info would be appreciated. He's asking $ 3500.. I'd be more receptive to $3K.

[kdxdazz]

It will all depend on how they have been revalved and set up, Motorcross forks in the woods are generally unbearable for older riders including myself unless revalved. Stock forks are actually quite good when set up well
USD forks only offer an advantage in ridigity which as you can imagine is a good thing when speed increases, if you went to the other extreme no trails bikes run USD forks because there is no speed

[Chuck78]

The stock forks are extremely heavy in comparison to most other forks as they are 1988 technology, and their longer travel versus medium ride height in a right sude up format gives that excessive underhang which can get caught on roots rocks and ruts. That being said, when valved and sprung properly vs stock settings, they will work quite well in the woods although lack external rebound adjustability and make the bike more top heavy.

As already stated above, the modified (re-valved) KX forks can be vastly superior, but inverted forks in general, when ridden around mud, will require more frequent seal cleanings and seal/bushing replacements than right side up "conventional" forks. The inverted forks will be substantially lighter (1/2 lbs to 4.5lbs lighter), but the big issue is they must be revalved for woods/trail/singletrack riding if you want to continue using the KDX for its designed purpose of woods/trail riding. Race Tech makes this fairly easy with their Gold Valve kits and online digital valving calculator software guidance. You will need to find out what year the forks are off of, and what model. It can be determined after the fact but can pose some difficulty and uncertainty in determining exactly what model / year they are

[SS109]

Since I have been running this basic setup for years, '90 KDX200 w/'96 KX125 KYB 46mm forks - '98 KDX220 w/ '06 KX250F Showa 47mm forks, here's my .02.

To answer your question, yes, USD forks are a serious upgrade if done right and they are revalved for off road and your riding style. The USD forks are way better at speeds above 20+mph and when taking the big hits. That said, the stock forks can be made to work great. I actually prefer them for super slow technical riding and when riding deep sand. That said, they absolutely suck, no matter what you do to them, when speeds get up there (+20mph) over rough/choppy ground IMO/IME. Reason being is that they just have too much flex. The USD forks eliminate this problem and any KX forks will also have better adjustability.

Now, on that price, I hope that is one primo bike for what he's asking!

[billie_morini]

I'm on board with SS109's comments above: "at said, the stock forks can be made to work great. I actually prefer them for super slow technical riding and when riding deep sand. That said, they absolutely suck, no matter what you do to them, when speeds get up there (+20mph) over rough/choppy ground IMO/IME. Reason being is that they just have too much flex."

I use the stock KDX 220 forks. My riding is predominantly in slow-speed technical terrain. I have a little less flex because I shortened the stroke on front and rear to lower the bike while retaining original geometry. When I shortened the suspension stroke, the springs were replaced for my weight and riding preferences. For tuning, oil type & quantity, clicker settings, and sag were systematically & thoroughly adjusted. I'm very, very pleased with the result and also pleased I saved big money by making the stock suspension perform optimally.

[NoBs]

Since I have been running this basic setup for years, '90 KDX200 w/'96 KX125 KYB 46mm forks - '98 KDX220 w/ '06 KX250F Showa 47mm forks, here's my .02.

To answer your question, yes, USD forks are a serious upgrade if done right and they are revalved for off road and your riding style. The USD forks are way better at speeds above 20+mph and when taking the big hits. That said, the stock forks can be made to work great. I actually prefer them for super slow technical riding and when riding deep sand. That said, they absolutely suck, no matter what you do to them, when speeds get up there (+20mph) over rough/choppy ground IMO/IME. Reason being is that they just have too much flex. The USD forks eliminate this problem and any KX forks will also have better adjustability.

Now, on that price, I hope that is one primo bike for what he's asking!

Yeah, I agree on the price. Problem is, a lot of the bikes are just too far ( 4 hrs to 10 hrs one way ) to take a look at. You rely on pics and info you get from the seller which is some cases is like playing dentist pulling teeth.. Amazing how negligent sellers are sending a couple of pics or a short video at least confirming it runs.. Very frustrating. Asking prices for whatever the reason even the GND's war on 2 strokes and lack of E start seems to be higher than a few years ago.. Now, there are many KTM's that can be had for the same or less.. Rented a couple of 300cc KTM's in the Mojave desert a few years ago, great fun but never got to see how it was in slower technical off camber wooded trails.

[NoBs]

Finally heard back, seems the guy has the stock forks and triple tree. The present UDF are set up for 180 lb rider which is about right for me. Seems he had the frame powder coated purple as is the seat. Looks like a good job but not that enthused over purple.. but it is what it is.. Gnarly Rev pipe ( does that make a real difference over the torquer version ? ) and stock rear silencer. It's a Vermont registration, no title per se if I understand correctly. I'm sure it could be had for less than $3K but probably not much less. Did I hear correctly that the Vermont work around is no longer valid ? Some pay to ride areas require reg and insurance but not inspection.

[NoBs]

Actually, forks are set for 200 lb rider.. Anyone know if the 2001 KX forks are taller than stock ? A little height impaired here.

[Chopperpilot]

I don't know for sure about 2001 KX forks, but I just set up, weighed and measured 3 front ends (triple trees, fork tubes, axles, wheels and tires) from a 2001 KDX, 1993 KX250, 2003 YZ250. The USD setups were at least 4lbs lighter, and lighter up top where it matters more. I put all the front ends (on 21" tires) on the floor and stood the fork tubes up straight and compared them. The MX USD setups were pretty even to each other, they were both about 1" taller to the top of the fork tubs than the KDX. Now how exactly that translates to ride height is up for a little debate. You can lower them in the trees a little.

[Chopperpilot]

my $.02 on USD forks vs stock. I don't particularly care how slow I'm going, I couldn't stand the flex in the stock forks. I like the bike to go where I point it, no matter how slow I'm going. Putting on the 93 KX250 forks was well well worth the effort to me.