Jump to content
Sign in to follow this  

Setting sag in forks 2005 KX250

Recommended Posts

Hey all,

I'm short and 130 pounds without gear. I'm trying to figure out a set up for my front forks. Yesterday I called PR2 and it surprised me that they recommended only one level lighter of a spring, at .42kg. Yet the rear spring was calculated at 4.8 So...

I do exclusively woods riding and hillclimbing. And up front in feels very stiff. I've already ordered a 4.8 spring for the back. Can I get away with the stock rate front springs? I was hoping that there's a way to adjust the sag, but I don't believe I have preload adjusters on this bike.

Suggestions? Sorry if this has been dealt with ad nauseum but I searched and couldn't come up with any answers. In fact, very little written on the sag issue. I also apologize for my very little experience in suspension. I'm still learning, but only by what I've read so far.

Thanks in advance.

Edited by Bron-Yr-Aur

Share this post


Link to post
Share on other sites

K tech chart says 0.39 and 4.5

Yeah that's where it gets confusing for me. PR2 said .42 and Racetech online calculator said .37. I hope that I didn't mess up ordering a 4.8 rear. Of course, anything has to be better than what I have.

Here's the situation (sorry I ran out of lunch break on my first post):

On a gentle flat landing from a jump, both front and back are nice and plush. But just cruising down a gravel road with occasional rocks, it seems like I can feel every little rock, from the front in particular. PR2 said possibly too much preload in the forks. But how do I adjust it?! I know very little about these cartridge shocks. I know conventional pretty well, but that doesn't help here, eh?

So .42 didn't seem like a big enough step to warrant $130+ shipping. Whereas going to a .37 or .39 would.

Clickers are out on compression and rebound. I'm thinking back in a little on rebound? But that still (I think) doesn't get to the root of the problem.

Edited by Bron-Yr-Aur

Share this post


Link to post
Share on other sites

You can measure fork sags ,you can alter preload on modern forks but it requires machining ,generally you need first to get the correct springs ,your std ones are way too stiff ,for mx expert speed 150lb you could use them ,for you I would say k tech is right and race tech is close PR2 imo is way off

Share this post


Link to post
Share on other sites

Thanks mog. I called Racetech this afternoon and ordered the .38 fork springs. I don't feel like messing around and trying to paint a turd.

I'm still mixed on revalving, mostly because of the cost. I know it might be worth it, but this is just a hobby. I thought about doing it myself, but it looks like it would cost nearly as much to go that route as to pay someone. I'm sure I could do it, but the investment in tools also comes into play.

I also hear that when the races are in town, Pro Action is there and can do it for less money than their usual. So I might explore that in the Spring.

Share this post


Link to post
Share on other sites
On 1/16/2016 at 1:31 PM, Bron-Yr-Aur said:

Thanks mog. I called Racetech this afternoon and ordered the .38 fork springs. I don't feel like messing around and trying to paint a turd.

I'm still mixed on revalving, mostly because of the cost. I know it might be worth it, but this is just a hobby. I thought about doing it myself, but it looks like it would cost nearly as much to go that route as to pay someone. I'm sure I could do it, but the investment in tools also comes into play.

I also hear that when the races are in town, Pro Action is there and can do it for less money than their usual. So I might explore that in the Spring.

Bron, any good feedback ???

Share this post


Link to post
Share on other sites
Bron, any good feedback ???

Hey buddy. Well, I bought a KTM (sorry! I almost feel guilty about that, but that's another story) So I only put about 4 hours on the bike with the newer springs before I put it up for sale. (Still have it too :() To be honest, it did help. But not nearly as much as I had hoped. My experience is exactly as I had read many times - springs are for setting sag, and valving is for the ride. Although they let the bike sit a little lower, which helped with my short legs, the ride was only slightly softened. I truly love the 250, but my 200 XC just fits my riding style better.

The KTM forks felt quite harsh too. Not surprising, since they are also closed chamber forks. But I did have them revalved and lowered, and the improvement is quite noticeable.

Had I stuck with the KX, I most likely would've swapped someone for their '04 and earlier open chambers. I just think they'd fit my riding (woods) style and light weight better.

Wanna buy a KX250??? 😉

Share this post


Link to post
Share on other sites

A 2005 KX250 ridden in the woods definitely needs a revalve. Even with the compression at full soft and the springs too soft for my weight, it still beat me to death in the woods.

  • Like 1

Share this post


Link to post
Share on other sites

Mines been revalved. Not bad except small choppy bumps, so wondering if springs will help. But I've just discovered my forks are slightly binding so initial park of the stroke is kind of dead/sticking.  Going to redo the pinch bolts etc and recheck it. If all good I'll test ride then, probably need to recheck my sag too 

Share this post


Link to post
Share on other sites
Mines been revalved. Not bad except small choppy bumps, so wondering if springs will help. But I've just discovered my forks are slightly binding so initial park of the stroke is kind of dead/sticking.  Going to redo the pinch bolts etc and recheck it. If all good I'll test ride then, probably need to recheck my sag too 

Sounds like the stiction you're getting is what's causing the problem. Don't mean to offend you, but I don't know you, or your knowledge: do you know there's an order for tightening the bolts and nut for your front axle? If not done properly, you'll get the stiction that you're experiencing.

That being said, I've come to just accept that for smallish rocks etc. the harshness of the CC forks is just something I'll live with. I'm getting use to it. Not much of a compromise tbh.

Share this post


Link to post
Share on other sites

Yep, and I thought I had installed it correctly but I reckon I didn't check it properly once done.  I've not done it very often but found a good post to follow this time around. I'm leaving today for a work trip overseas for two weeks so I'll sort it on my return (hopefully !). 

Share this post


Link to post
Share on other sites
On 3/25/2017 at 9:47 AM, KDXGarage said:

A 2005 KX250 ridden in the woods definitely needs a revalve. Even with the compression at full soft and the springs too soft for my weight, it still beat me to death in the woods.

what have you done so far on the KX in terms of improving the forks?  According to Kawasaki the stock 0.44 springs are good for my weight (170) but I suspect that is for MX racing not woods.  i'm thinking of going down to a 0.40 which RaceTech recommends.  I was trying to research the ICS but too confusing so far... some people seem to say go softer and others say to simply sort out the main spring only

 

my front sag is only 50mm, whereas it should be 65-75 from what i've read?  that's what lead me to this post, and i am wondering about the softer springs

Edited by Chris Gibbons

Share this post


Link to post
Share on other sites

50mm is a bit low for woods 65mm would be better

Share this post


Link to post
Share on other sites

65mm total sag from on stand to with rider , almost half what the rear sag is

Share this post


Link to post
Share on other sites
On 3/26/2017 at 4:53 PM, Chris Gibbons said:

what have you done so far on the KX in terms of improving the forks?...

I bought a YZ250. :ride:

 

If you are in the woods, then they will need to be revalved.

 

Share this post


Link to post
Share on other sites

I'm not going to watch it as I have measured tons if fork sags and 45mm for crazy fast riders, 55mm for most mx riders, 65mm for woods

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  

×
×
  • Create New...