KDX220 handling

[KDXGarage]

You need to compress it one inch, then see how much force is needed to compress it one inch (from 1 to 2). Measuring from zero to one is not an accurate way to measure spring stiffness. If you have the equipment, measure from 2 to 3 also to confirm the 1 to 2 measurement.

400 mm is way too low if you are measuring it properly.

[vchris]

For the 400mm i was just eyeballing with a tape on the outside with the forks slightly lifted.

As for measuring spring rate, I'm having a really hard time finding how tos. I have basic tools. I used a bathroom scale. Possible to point me to a good resource?

[KDXGarage]

Do you have any workout type weights?

I can explain how I used to do it.

[vchris]

I have my gf 2-5-8lbs dumbbells. I have general tools but no dirt bike specific.

[Goofaroo]

What is the complaint with the handling other than “it doesn’t feel like a KLX300”?

Does it wander or seem hard to steer? Have you checked the steering head bearings? Do they feel rough, loose, tight, or indexed in the straight position?

Does the shock seem to have proper dampening or is it basically a pogo stick?

Do the forks have oil running down the lowers?
Proper static sag when installed or at least in the ballpark of around an inch under the bike’s own weight?
Most importantly are you frequently bottoming the forks while riding?

Your bike is not a KLX and will never be a KLX. However it should be a great handling bike and a helluva lot of fun even in stock form. If there’s something wormy about how it rides it ain’t the fork springs or tire pressure.

Are you bottoming the front end routinely when you ride?
Have you checked the other things I asked about?
I have a feeling you have a combination of issues.

[Goofaroo]

Have you checked the wheel bearings? There should be no slop if you try to wiggle the wheels.

Also, do you have a work stand? Could you put it on the stand and send us a front view and side view of the bike with the front wheel aimed straight ahead?

If you don’t have a stand it might still help to send us some pics of this bike.

[KDXGarage]

OOPS! I must not have clicked the Submit button on my previously typed up reply.

I used a broom handle, a measuring stick, workout weights with a hole in the middle and a vise (to hold the stick steady and aid in measurement. Measuring from zero to one was poor. Measuring from one to two was accurate. Measuring from 2 - 3 was nearly identical to 1 -2.

[Goofaroo]

What is your riding experience? You said you bought this bike two years ago. Was it your first bike? Have you only ridden 7 times?

A two stroke like your KDX is much more abrupt than a four stroke like the KLX. It is also lighter. One way to describe it is that you’re riding a gas engine and 4 stroke KLX is a diesel. A two stroke revs in a hurry. Even modern four strokes don’t have the majestic,wheel spinning, right now, instant pep that a two stroke has. That is not to say that one is faster than the other. They’re just different.

Anyway, your bike should be a blast to ride. And so will a KLX. I have an 85 XR350R that I’ve owned for 26 years and an 87 KDX200. I love the pep and playfulness and flickability of the two stroke but I also enjoy kicking back on the XR and letting it pull me through the woods without all the throwing roost an sliding around.

Again, I know nothing about your riding experience but there’s no comparison between the two bikes.

My advice? Get the KDX dialed in. You’ll
love it! Then buy a KLX and keep the KDX.
lol

[vchris]

@KdxGarage Your method seems very similar to mine. So basically use a bathroom scale and press on it from 1-2 inches and check lbs pressure on scale right? What's the formula? I have a feeling the springs have been changed since they look so new. Might not be my issue. Maybe one thing I could try is click it up a few times to increase pressure and see if that changes the front wheel washout feeling when cornering?

@Goofaroo The wheel bearing looks fine, no play. Forks don't have any weird feeling. It's winter now here so it's been a while since I rode it but the feeling is kinda like it's gonna wash out on every turn I take so I have to slow down so much so that I'm left behind.

[vchris]

Just compressed fully the suspension with my jack and measured 7 inches from top is where the oil is, no spring. That would make the front forks pretty soft no?

[KDXGarage]

compress it one inch, then zero the scale (or make a note that the shown value is really the start). You need to compress it one more inch, then measure that, then go from 2 to 3.

pounds per inch can be converted into Kg per mm. 19.558 pounds per inch is the stock rate. In a perfect world, you would need about 58.674 pounds of pressure to compress it 3 inches.

If the oil level was 7 inches, then did it leak out? I bet it was plush. (WOW)

[vchris]

I guess I could add the scale below my jack and try it. I never saw any oil leaking or streaking on the forks. I guess that would explain the feeling while cornering?

[KDXGarage]

Are the forks fully compressed or just jacked up as high as they would go?

[vchris]

Jacked up as high as they go before lifting the bike. Look at the pics in my previous post.

[Goofaroo]

They’re fully compressed in the picture. As I recall the useable range is listed as 85 to 100mm. 85 will be more firm due to the lower amount of air volume which compressed quicker.
But check the numbers for your specific bike.

Ideally you would pull the fork legs off the bike and hold them straight up to measure the level. You can also thoroughly drain them with them off if you’re changing the fluid. 5wt is most likely standard. You may prefer 7.5 or 10 but for now you just need to get it within the operating limits.

[SS109]

I'm gonna throw my two cents in here.

IME most front end problems tend to be caused by the rear end setup. Sometimes adding a click or two of compression on the rear will help keep the front end planted in a turn. You can also increase rear spring preload 1mm to have a similar effect. Plus, you can always slide the forks up in the triple clamps 1-2mm.

See, all three of these adjustments help keep more weight bias on the front tire which helps keep it planted. However, like all things dirt bike suspension, everything is a compromise and you have to find the balance that works for you.

What are your sag numbers? Where are the forks set it the triples, flush or ???

[Goofaroo]

@KdxGarage Your method seems very similar to mine. So basically use a bathroom scale and press on it from 1-2 inches and check lbs pressure on scale right? What's the formula? I have a feeling the springs have been changed since they look so new. Might not be my issue. Maybe one thing I could try is click it up a few times to increase pressure and see if that changes the front wheel washout feeling when cornering?

@Goofaroo The wheel bearing looks fine, no play. Forks don't have any weird feeling. It's winter now here so it's been a while since I rode it but the feeling is kinda like it's gonna wash out on every turn I take so I have to slow down so much so that I'm left behind.

You won’t answer my question about frequently bottoming the forks. That would be nice to know but you obviously
don’t want to tell us so let’s move on.

You say you’re getting left behind. Trade bikes with one of your riding buddies and see if they get left behind. If so ask them what they think is wrong with your bike.

If you are still left behind the mystery is solved.

[Goofaroo]

And have your buddies check your steering head bearings.

[Goofaroo]

I'm gonna throw my two cents in here.

IME most front end problems tend to be caused by the rear end setup. Sometimes adding a click or two of compression on the rear will help keep the front end planted in a turn. You can also increase rear spring preload 1mm to have a similar effect. Plus, you can always slide the forks up in the triple clamps 1-2mm.

See, all three of these adjustments help keep more weight bias on the front tire which helps keep it planted. However, like all things dirt bike suspension, everything is a compromise and you have to find the balance that works for you.

What are your sag numbers? Where are the forks set it the triples, flush or ???

I asked him if the shock even had any dampening or if it is just a spring but he wouldn’t say. Actually, we know very little about his bike. It looks to me like he just needs to dump some more fluid in the forks and toss the springs back in. He wouldn’t say if they leaked.

If he actually has a problem I am guessing in order:

Rider skill
Steering bearings
Something he won’t tell us about the forks
Shock is a pogo stick

[vchris]

@Goofanoo I answered all your questions in a previous post, read up. I ordered some 5wt and we'll see how it feels this spring.

@ss109 I think you're right. I can't ride now, just got 15 cm of snow. But I remember the rear being somewhat squishy when sitting.