Jump to content
Sign in to follow this  

kx450f washing out in corners...please help

Recommended Posts

Iv got a 08 kx450f with 2012 suspension.. I am a 150lbs rider.. I am having a realy tough time get my suspension right.. when im ridin my front end always washes out on me in any turn. I have the front forks up in the stock clamps at the second line below the cap. My rear sag is set at about 100mm.my front compression clickers are set at20 clicks out and rebound is at about 12 clicks out.. rear high speed it one turn out.comp is about 11 clicks abd rebound is about the same maybe a few more out... the front end is realy shakey at high speed and corners rhe front pushes out and makes me fall.. someone help me out please!!!

Share this post


Link to post
Share on other sites

I can tell you just by looking at the clickers that since they are 20 out that your front end is too soft. Try a more normal setup like 10 comp and 10 rebound.

Share this post


Link to post
Share on other sites

Understeer (front end pushing, washing out) is a problem for most MX bikes because of the shallow head angles needed to deal with the outrageously rough ground they have to run over.

To start with, when cornering, move well forward on the bike...all the way up front. Next, you say you weigh 150. Whether that's with or without gear, that's light for your stock springs if you are still using them. You have said that your sag is 100mm, and I'm guessing that's rider or race sag, with you on the bike. What is your STATIC sag (bike on the ground with no one on board)? If your springs are too stiff for your weight, the front will not settle as far as it should in corners, and it will push dirt instead of turning.

Share this post


Link to post
Share on other sites

i am about 150lbs with no gear... i got the bike from a guy that was 210lbs about a month ago... as for the springs... the rear looks stock and i have no clue if the fork springs have been changed.. i have set up my sag with a normal tape measure. when the bike is on the stand.. from the swing arm the a spot on my fender it reads 26 1/2 in... when the bike is on the ground without me on it drops to about 24 1/2in.. when i get on it, it drops to about 22 1/2 in.. what do yall think??

Share this post


Link to post
Share on other sites

i am about 150lbs with no gear... i got the bike from a guy that was 210lbs about a month ago... as for the springs... the rear looks stock and i have no clue if the fork springs have been changed.. i have set up my sag with a normal tape measure. when the bike is on the stand.. from the swing arm the a spot on my fender it reads 26 1/2 in... when the bike is on the ground without me on it drops to about 24 1/2in.. when i get on it, it drops to about 22 1/2 in.. what do yall think??

Sounds like your springs are too stiff

Share this post


Link to post
Share on other sites

The rear spring is too stiff at least. If the fronts match it, so are they.

Here's what your info tells me: There are two sag dimensions you can use comparatively; Rider sag (race sag, loaded sag) and static sag (free sag, unloaded sag). The rider sag is adjusted first to specification, which is normally around a third of total travel. You have something like 12 inches of rear travel, so we use 4" for that. Then, to determine whether the spring rate is correct, we can compare this to the static sag. "Correct" static sag is a little less of a solid number, but it hovers around 1-1 3/8" (25-35mm). You have a static sag of 2". Why?

You have an excess of static sag because the spring is too stiff for you. That means that it did not need to be preloaded to its normal amount to support your weight at a 4" sag. Because it's not preloaded enough, it lets the bike sag too much under its own weight. If the spring were too weak for you, the opposite would be true.

It's easier to visualize if you reverse the adjustment and do the static sag first. What would happen if you have a too stiff spring and you set it to 1" of static sag. You sit on the bike, and what? Not enough race sag, right? So you lower the bike to the right race sag, but now where's the static sag set? See?

Try the same measurement with the fork. With the rider in place, the fork should settle "roughly" (there's more than a little discussion about this) 25% of travel, so about 3". If it won't, you need front and rear springs to match your weight, and that will very likely make a major difference in the handling overall.

Share this post


Link to post
Share on other sites

what springs should i get for my weight being a 150lbs rider?? front and rear??..... right now money is tough soo is there anything i can do to fix it for the time being to feel a bit better untill i get the money to re-spring it?

Share this post


Link to post
Share on other sites

Around about .45-.46 kg/mm in the front, and a 5.1 kg/mm in the rear. Yes, both ends. Yours are a lot too heavy by the look of things, even if they're stock.

Nothing you can do short of respringing is going to really fix this problem.

Share this post


Link to post
Share on other sites

To get you by for the weekend. Since you are out 20 on comp. Go to your rebound on your fork and slow it a bit. Just go 2 clicks to see

if it helps.

jw

Share this post


Link to post
Share on other sites

ok fellas.. i have 2012 kyb AOS suspension on my o8 kx 450f... i am about 150lbs.. i just got 5.2 rear race tech spring and 46 kyb springs for the forks...i have already put the rear in.. i have my front forks off and i was woundering if you pull the forks apart the same way as a regular fork... correct me if im wrong.. loosen the top cap, drain the oil from the tube.. unscrew the bottom, hold the push rod and finish unscrewing, pull the inner tube from the outer with the spring, put the new spring in and oil and im good...do i have to change the inner tube oil or can i just put new oil in the outer tube... how much oil do i put back in??? please help..

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×