Author Topic: KX250 rear supension  (Read 5125 times)

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Offline GRARA

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KX250 rear supension
« on: January 29, 2015, 01:11:59 AM »
Quick question here.....the rear end of my 99 KX250 seems to be sitting a little lower than usual,i can lift the bike(from under the seat) when its on the ground about an inch before the wheel comes of the ground.Is this a problem with my shock? or is this normal?

Offline Foxx4Beaver

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Re: KX250 rear supension
« Reply #1 on: January 29, 2015, 01:42:54 AM »
a properly set-up rear shock will/should have roughly an inch of free sag.
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Offline Foxx4Beaver

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Re: KX250 rear supension
« Reply #2 on: January 29, 2015, 01:51:18 AM »
more importantly, have you ever "set the sag" before?....if no, this can make such an improvement in how it handles and soaks up bumps and hits if you take the time and set it with a buddy to help.
you may find you need a different spring for your weight/riding skill...but it'll all be money/time well spent.
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Offline sandblaster

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Re: KX250 rear supension
« Reply #3 on: January 29, 2015, 02:39:26 AM »
Excellent advice Foxx, that's where I would start.
If you have already checked your sag and it's still a issue, you will need to check your swingarm and Uni Trak bearings.
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Offline umberto

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Re: KX250 rear supension
« Reply #4 on: January 29, 2015, 11:04:38 AM »
The swingarm bearings can get pretty bad if they have never been replaced, and can cause a lot of slop in the rear suspension. A buddy of mine had a 2000 KX 125, and it had a clunk in the rear end that was about an inch or so of the travel.  The bearings were roasted and missing a lot of the needles.  The bike itself was in decent shape, but I guess the bearing had not received any attention since it was new. 

Do you hear any noises when you lift the bike up that inch or so?  If all you hear is the shock decompressing, I would start with the sag.  If you hear a pop or clunk, I might try pulling the bearings just to have a look.  If they are in good shape, you can re-grease them and check that off the list.
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Offline GRARA

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Re: KX250 rear supension
« Reply #5 on: January 29, 2015, 07:04:34 PM »
THanks for the input guys,the sag was set last summer so no problems there,there is no clunks or squeaks and there is no play when the rear is off the ground.
It also seems a bit soft back there...either ive put on a few extra pounds over the festive period or there is something wrong lol

Offline Foxx4Beaver

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Re: KX250 rear supension
« Reply #6 on: January 29, 2015, 10:23:15 PM »
It also seems a bit soft back there...either ive put on a few extra pounds over the festive period or there is something wrong lol

sounds like a stiffer spring is in order....and, if you've never had it done yet, it wouldn't hurt to have the shock rebuilt/re-valved for your weight, skill, and type of riding you "usually" do....that'll cure your "soft" feeling. :-)
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Offline Hillclimb#42

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Re: KX250 rear supension
« Reply #7 on: January 30, 2015, 01:14:37 AM »
I have been rebuilding shocks and forks for a short time. It's very important to charge the shock with nitrogen. These other suggestions are all very good. Spring check is definitely first. Sag being right is definitely a priority. Linkage frIction is also a real issue that is hard to realize. The best way to do sag that people often overlook is to consider your linkage friction. Push down on the seat a few bounces. Measure the point that it is there. Then lift the seat and let it return and measure. The difference between those two is the actual point to measure. Also the clickers, they need turned all the way in and then the setting is how many clicks out. Know how many clicks are in your adjustment range. It's easy to lose track of and be all the way soft.

Offline don46

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Re: KX250 rear supension
« Reply #8 on: January 30, 2015, 08:47:19 AM »
When was the last time the oil was changed in the shock? We we raced MX I would change oil at least 3-4 times per year and recharge, the oil does break down over time. I use Redline and have good success, I recently bought a race tech shock bleeder, it sure makes the job easier and does a better job than the manual method. I think the rear suspension is the most overlooked part of a bike. New Kawis have little to no grease in the bearing, that is the first thing that gets done on my new bikes, then ride the crap out of them a couple of times and then set the suspension, which is an ongoing process.
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