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I have question, I own a 05 KDX 220 and was wandering if anybody had high speed crashes where the front end just goes out from under the bike. This has happened to me 3 times the last resulting in a broken right leg and foot. I know a lot of factors are involved, but it seems I have read about stability issues with the front forks.

I crashed one time going at least 55 in the desert, I was in either 5th or 6th (don't remember it) and I hit a ditch and went end over end. Bruised 3 of my lower vertebra, sprained both wrists, rasberried my entire back, bruised hips, knocked the wind out me, it goes and on. Luckily though I didn't break anything, I remember flying through the air though and thinking "I really don't want to break anything...". I ended up riding another 80miles that day, PAINFUL!

I've also heard something about the KDX forks being that way, it has something to do with the rake. What I was told this morning when doing my suspension that I should lower the forks in the clamps for high speed stuff to resist tank slap. Anyone care to elaborate/correct me?

The common misconception with fork height is that if you lower the front of the bike, then more weight is placed on the front tyre and a more planted feel will ensue. What actually happens is that ground trail is reduced meaning less torque is produced upon the side of a turned tyre. This results in less grip which in turn results in the pushing of the front wheel accompanied by a very light or "flighty" feel. Raise the front of the bike and a more positive feel will be your reward.

The KDX forks are as useful as a mans nipple and you are asking to get hurt if you push their limits IMO.

The stock front forks like Kay Dee says, are nearly worthless. But I used to ride my bike occasionally as fast as it would go (a little more than 70 mph) and while it wasn't anything near confidence inspiring, it didn't feel like I was a dare devil either.

What gets you into the high speed instability is a number of things. It's partly a compromise on making a nimble steering bike for tight trails, part crappy forks (too noodly, and way too soft on the springs) nothing up there is remotely balanced, and there's no steering damper. Oh, and if you didn't lube the steering head bearings when you got the bike, they may well be shot now.

I put a steering damper on mine and it felt dramtically better at speed (everywhere else too).

I say service the bearings, spring it if you don't intend to do the right thing (swap to KX forks) and put a damper on it.

thebleakness wrote:What I was told this morning when doing my suspension that I should lower the forks in the clamps for high speed stuff to resist tank slap. Anyone care to elaborate/correct me?

For higher speed stability you want the top of your forks flush with the upper triple tree. Tank slap can have numerous contributors - If the forks are raised in the clamps (more weight bias on the front wheel) or your springs are soft in the forks (weight bias on the front wheel) or your rear shock is set up without adequate rider sag (weight bias on the front wheel) are a few. See some similarities? This is a generality but the bike needs to be "balance" more or less with the rider. Then the rider's input becomes much more effective in driving the bike though what ever the terrain is.

I'm one of those people who thought the stock forks once sprung right and with adequate rebound control due to oil viscosity were not half bad even at speed. Although "at speed" was on fire road type terrain. May not inspire over confidence but neither did it give me the willies.

If the bike is suddenly washing out and putting you on the ground without warning I would ensure the following. My forks were sprung for my weight, the rear shock was sprung for my weight and I had set the ride sag in the ballpark of where it should be, the front tire was decent for the terrain and aired up in the 11- 14 psig (IMO) range, and that I the rider was in the correct position on the bike for the terrain and speed. (I'm assuming abunch of stuff - your forks are functioning correctly, no binding issues, they are installed correctly, your shock linkage is not binding or frozen up, shock is working, clickers are set in the ball park, etc.)

If the mechanical side is good then dear friend you may need to evaluate your riding style. When is the bike washing out? turns or braking bumps, etc. What is your riding position? Over the tank, standing over the pegs, sitting on the seat more of less centered, etc. What is the terrain when the washing out occurs? Sandy, hardpack, loam, rock, loose rock, etc.

FWIW - I'm by no stretch of the imagination an expert or even a fast rider but I've had enough experience over the years to recognize signs and symtoms of improper set-ups and of course experienced and witnessed rider induced crashes.

The terrain is was riding in was different all three times I crashed. I have a set of KX 125 forks I intend on being built during my healing time. I ride standing up, I am 215 lbs so I know the stock springs are no where near the ball park, but my SAG was set right with what I had. I did notice in the second time the front end washed out it wobbled the went, I was just curious if anybody had this happen to them. Thanks

I can tell a big diff from riding my 97 KDX 200 at top of 5th and 6th gear on medium terrain/sand and then riding my buddies 03 CR250R his bike just wants to go faster and you aren't scared to with my KDX I find my self backing off because I can tell the handle bars is going to start shaking anytime

But then when we switch on the trails it is like night and day his is way to torqy and touchy on the trails and doesn't handle well on the trails, So I guess it is just what kind of riding style you do most.

KDXer wrote:

The KDX forks are as useful as a mans nipple and you are asking to get hurt if you push their limits IMO.

What a bunch of CRAP!

A 200+ lb man and stock springs are like oil and water. You WILL crash at any speed because, regardless of preload, your springs are already way too far compressed to provide the correct ride height and terrain response under varying loads. Loading the front end for a turn must be a joke.
I agree with IdahoCharlie, even the stock forks, if properly set up with the correct springs and oil height, are usable at any speed -

kawagumby wrote:A 200+ lb man and stock springs are like oil and water. You WILL crash at any speed ,

WTF?

again (see above)


Make it sound like, no matter what, you are gonna crash

I'll admit the bike won't handle that great but "crashing at any speed"


Smells like cow poop to me

Ah, Mr. Wibbens.....read closely and you will note that I referenced a 200+ lb man riding a bike with the stock sprung forks... and yes, UNLESS you are riding only in a straight line, on level ground, centering your body carefully so as not to disturb the delicate balance of your precarious perch, on carefully prepped soil of at least 95% relative compaction, containing no projecting rocks greater than 1 inch in diameter, nor cellulose debris exceeding 6 incbes in length, nor animal matter, such as cow poop that has been allowed to harden.... If you dare exceed these riding condition parameters, yes, you WILL eventually crash due to bike suspension setup. This has been demonstrated by careful field experiments done at the University of Kawasaki Heavy Industries testing site by a team of dedicated world-renowned scientists fully funded by an independent public broadcasting system affiliate. I can get you the URL for the report if you like.

What's that URL?

Ummm, sorry, but I've had problems getting it from the Library of Congress website. Evidently, the Bush Administration has had it reclassified to a higher security level.
I'll keep you guys posted when I get to the bottom of this.

Read closely,

I poop the equivalent of +200 lb guys everyday

I rode my KDX a long time on the stock suspension

Can't think of any crash in particular that would have been avoided with proper suspension, usually they were all rider error and occasionally alcohol may have been a factor too



Don't make me show the lower half of this photo!

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Clearly, even that carefully censored photo gives away an athletic frame that could easily give you an edge when it comes to riding prowess, possibly explaining your different perspective on this matter.

There was a mention of riding fast, sounds like, just goood old under hang grab.

I think the 'what a bunch of crap' in response to what KAYD said comes from Mr. Wibben's evident superior point of view of the use of a man's nipple.

...uh..that IS what he said, right? Really...he even showed a pic of one to make his point!!



Maybe I missed something...


The KDX OEM frontend is usable..it's just not AS useable as a better frontend.

IC named a bunch of things relative to 'washing out'. Add tire choice and inflation, too. Two psi makes a noticeable difference. Unfortunately, there isn't a perfect setting for all terrain..and most rides will get you into something that would ride better if the front inflation was different.

Other things being equal, a bike with a rebound control function will outperform a bike that ain't got none'a that.

I could take a bike with the best front end known to man and STILL lose the frontend!

My two-cents.....

1. Riding above your ability (too fast?)
2. Not paying attention
3. Riding behind someone with better suspension
4. Thinking your stock KDX suspension is the same as #3 above
5. Drunk
6. Lack of steering stabilizer (Damper)

I've done all 6 above. Removing 1 - 5 above, I find I can ride and keep up with anyone. I've spent considerable time getting the clickers right for the terrain I ride, and the spring/sag. I used to 'crash' often on my XR4. Since I got the 220 (year & a half), I haven't crashed in, well, a year & a half (stopped tippin' the bottle, too). Stock springs, forks high in the triple-clamps (for tight turns), heavy oil (forks), sag set, no crashes. I put on a Scott's stabilizer this year as well, and it's saved my butt more than once. Good investment. I rode 80 miles, tarmac & dirt, on Saturday, top speeds around 65mph (I DO have a 51T rear FCOL), and no head-shake.

Stop blaming the suspension, and look in the mirror. Tough love. I blamed everything in the book, and realized I wasn't as good of a rider as I thought. I now learn, I now follow, I now get better, every time I ride.

95% Rider, 5% bike.

No disrespect intended, but if you ARE crashing due to the bike, go through it, top-to-bottom. Find out if it's something serious. We want you around!

-- C.J.

(Flame Protection On, not that it matters. I'm just tired of everyone complaining. STFU and ride it - it's not a La-Z-Boy, it's a dirtbike )

95% rider, 5% bike

You know how adages come to BE adages?.....'cuz they're true most of the time.

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Mr. Wibbens wrote:Don't make me show the lower half of this photo!

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