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2010 KX250F spring rate advice needed

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Hey guys, after hardly riding my 2010 KX250F for the past year, I've decided to get back in to training and riding more regularly and putting it to use.

I weigh about 170 pounds WITHOUT gear, and am an A level rider, the stock suspension seems to be somewhat stiff on the small bumps, and there is not enough bottoming resistance for the bigger jumps and G-out sections of the track. It would seem i should go up on the spring rates, what spring rates do you guys recommend i try?

The race-tech calculator recommends .46 fork springs (stock is .44), and they recommend the stock 5.4 rear spring. But is that calculator truly reliable?

The calculator also says the the WRONG stock springs for my bike :smirk: . ??

Any help here is appreciated! Thanks in advance!

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4.2 n front 50 n rear that's for 75kg to 80 kg unkitted. You should be ok on rear spring try what's your sag

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4.2 n front 50 n rear that's for 75kg to 80 kg unkitted. You should be ok on rear spring try what's your sag

Thanks for the response but your recommending i go softer on the springs, they are too soft already it seems, when im charging aggressively it blows through the stroke and bottoms in sections that it shouldnt, which makes for erratic handling, it gives the sensation of feeling stiff since its bottoming, but the forks are too soft, at least that is my feeling.

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So no one on here in my weight range has tried stiffer springs on this bike?

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I currenly help tune an a riders kxf250. You want to go to a stiffer front spring and revalve on the fork leg. Pro circuit has a decent setup for these new forks.

Al

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Oh sorry, I did not see the 2010 listing scratch that.

those bikes in that year tend to push alot in corners

mid rangr harsness in the factor there.

A revalve for your riding abuility shoud do the trick.

make sure you set the rear sag 100-105 mm then check the front sag, it should be 1/3 stroke of range.

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Oh sorry, I did not see the 2010 listing scratch that.

those bikes in that year tend to push alot in corners

mid rangr harsness in the factor there.

A revalve for your riding abuility shoud do the trick.

make sure you set the rear sag 100-105 mm then check the front sag, it should be 1/3 stroke of range.

What do you think about trying 0.46Kg.mm fork springs which are slightly stiffer than stock??

Thanks for the response btw, i dont want to ship my stuff out for a revalve since i am not in the US and when i did that last year for my previous bike the shipping was too expensive.

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it's more a valving problem than springs your springs are right

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it's more a valving problem than springs your springs are right

IT seems i get them to bottom too regularly though..which is why i thought the stiffer fork springs might be good to try :smirk:

I dont want to ship my suspension out its very expensive so from where i am, what do it yourself kits would you recommend?

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there is a thread on here about the same bike as yours in terms of valving , you don't need expensive kits

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Hey guys, after hardly riding my 2010 KX250F for the past year, I've decided to get back in to training and riding more regularly and putting it to use.

I weigh about 170 pounds WITHOUT gear, and am an A level rider, the stock suspension seems to be somewhat stiff on the small bumps, and there is not enough bottoming resistance for the bigger jumps and G-out sections of the track. It would seem i should go up on the spring rates, what spring rates do you guys recommend i try?

The race-tech calculator recommends .46 fork springs (stock is .44), and they recommend the stock 5.4 rear spring. But is that calculator truly reliable?

The calculator also says the the WRONG stock springs for my bike :ride: . ??

Any help here is appreciated! Thanks in advance!

I've got the '10 KX450 and tried several different set-ups, including spring rate and valving, starting with Factory Connection, and ending with Dave J at Smart Performance. I'm 170#'s w/o gear, Vet B rider. For spring rate - tried every rear spring from 4.9 to 5.5, finally settled on a 5.1 to get the sag set correctly - 102-106mm. Factory Connection recommended a 4.9/5.0, but everyone else recommends the stock spring for someone our weight, however, I could not get the correct sag with that spring, and I tried a couple 5.4's to make sure that the first one I tried was not really a 5.4.

As for valving - I highly recommend you talk to Dave J. He has the '10 KX 450 set up absolutely dialed. I was unhappy with FC's set up.

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there is a thread on here about the same bike as yours in terms of valving , you don't need expensive kits

mind posting the link to that thread? ive searched but couldnt find any advice relating to my situation..thanks

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I've got the '10 KX450 and tried several different set-ups, including spring rate and valving, starting with Factory Connection, and ending with Dave J at Smart Performance. I'm 170#'s w/o gear, Vet B rider. For spring rate - tried every rear spring from 4.9 to 5.5, finally settled on a 5.1 to get the sag set correctly - 102-106mm. Factory Connection recommended a 4.9/5.0, but everyone else recommends the stock spring for someone our weight, however, I could not get the correct sag with that spring, and I tried a couple 5.4's to make sure that the first one I tried was not really a 5.4.

As for valving - I highly recommend you talk to Dave J. He has the '10 KX 450 set up absolutely dialed. I was unhappy with FC's set up.

:ride: We just finished a 10 kxf 250. I believe we got this setup dialed too with the Dell taco 3rd. Generation. This was for a Vet A racer at 160 lbs without gear.

To the OP, If you bottoming harshly you can try raising your oil level height 5 ml at a time until you stop bottoming. Of course you might be get some harshness. The stock mv is ugly on this fork.

You may need to go up 1 rate on the front. If your blowing through the stroke everywhere, you need help with the mid valve. IMO.

jw

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james, i told him to call dave, im not bottoming the new set up. i just lowered the oil ht. a little. this is with stock springs

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Run a single stage stack in those forks instead a two stage

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