2010 spring rate questions here

[adamdf]

Hey guys, i am 170 pounds WITHOUT gear, and am an A level rider. I haven't ridden my 2010 KX250F much in the past year, kinda took a break but am planning to be riding as often as possible once again.

The problem i had with the bike from the start, is when charging hard or coming up short on bigger jumps, the suspension bottoms a bit too much, too regularly. The suspension also seems a bit harsh in the initial part of movement (over small bumps). I think for my weight and skill level i am going to need stiffer springs.

I want to test different rates for this reason. Any of you guys with the same or similar characteristics as myself tried stiffer springs either front/back or both?

And out of curiosity, what sag numbers have some of you liked the best on the 2010?

Thanks in advance everyone!

[Kx_Ryan21]

These are the numbers racetech has for you and your bike.

Modifiers:

Riding Type: Motocross

Age: Standard Age - Up to 44

Skill Level: Dirt Amateur

Height: Standard Height

Weight: 170lb

Gas Tank: Standard Gas Tank

FRONT FORK SPRINGS

Recommended Fork Spring Rate: 0.449 kg/mm (use closest available)

Stock Fork Spring Rate: 0.45 kg/mm(stock)

REAR SHOCK SPRINGS

Recommended Shock Spring Rate: 5.2 kg/mm (use closest available)

Stock Shock Spring Rate: 5.1 kg/mm (stock)

Looks like your forks springs are perfect and your rear spring in only a little light. Get a good revalve and you will be golden.

[adamdf]

These are the numbers racetech has for you and your bike.

Modifiers:

Riding Type: Motocross

Age: Standard Age - Up to 44

Skill Level: Dirt Amateur

Height: Standard Height

Weight: 170lb

Gas Tank: Standard Gas Tank

FRONT FORK SPRINGS

Recommended Fork Spring Rate: 0.449 kg/mm (use closest available)

Stock Fork Spring Rate: 0.45 kg/mm(stock)

REAR SHOCK SPRINGS

Recommended Shock Spring Rate: 5.2 kg/mm (use closest available)

Stock Shock Spring Rate: 5.1 kg/mm (stock)

Looks like your forks springs are perfect and your rear spring in only a little light. Get a good revalve and you will be golden.

Race tech calculator is off, they say the stock spring is a 5.1 when its 5.4:bonk:

Thanks for the post but lets discount race tech for now:thumbsup:

[Kx_Ryan21]

Huh, my apologies. I have always found race tech to be spot on.

[DMauro]

they are both wrong is a 5.2 kg, the 2010 has very little pergresion in the fork valving i felt the same thing. i wt. 162 with out gear and use stock springs. you would need a revalve. just helped dave from smart performance with a new set up for this bike that resist bottoming well. we are still working on the shock.

[DMauro]

r u sure race tech didnt say 51 N mm, thats a 5.2 kg

[Kx_Ryan21]

I copy pasted it directly.

So youre looking at what it said, I made no changes to it.

[DMauro]

yes i ment race tech is wrong, my manual says 5.2 and Fc and others said the same. maybe the other guy with the 5.4 is a europian model

[adamdf]

yes i ment race tech is wrong, my manual says 5.2 and Fc and others said the same. maybe the other guy with the 5.4 is a europian model

Lets not get confused here, i have a US model 2010 KX250F, according to motocross action and mx-tech, the 2010 model has a 5.4...

dont you have a 2010 as well dmauro?

[adamdf]

Ok guys my mistake, the manual says the 2010 spring is a 51 N.mm which is a 5.2kg.mm , but why does mxteck and MXA list the stock rate at 5.4 Kg.mm? whats going on here?

[DMauro]

i dont know why? but the stock rate is close for you. are you bottoming front and back?

[adamdf]

i dont know why? but the stock rate is close for you. are you bottoming front and back?

In G-out sections and hard landings i feel it bottom, i dont think its the shock, i think it is the forks, which also tend to transmit a harsh feeling at times on square edge bumps etc which tells me i could be riding them in the wrong part of the stroke, maybe i should try the 0.46kg.mm springs in the front? What ya think Dmauro?

Once again, even though i may be in the target weight range, i am an A rider so im going to push the suspension more than the average B or C rider which is why i'm thinking i should try stiffer springs up front, but i know you have done some testing with this bike already and you may know better than me.

I am trying to do this myself because i dont live in the US and sending my stuff out to RG3 last time proved to be too expensive shipping there and back, if anything i would rather a do it yourself kit from Smart performance or the like.

[DMauro]

you could go softer on the ICS spring, and increase your oil ht from stock 360cc to 370-375 for the bottoming. the smart performance fork kit i have now is stiff and would be good for an a rider. but with stiffer suspension you wll feel some in your hands there no way around it. as far as the fork spring WT the manual says .45 but FC tells me there a .46 and the manual was never changed. like i said earlyer the shim stack has no pergression to it. maybe someone else can sugest a stack for you.

[adamdf]

you could go softer on the ICS spring, and increase your oil ht from stock 360cc to 370-375 for the bottoming. the smart performance fork kit i have now is stiff and would be good for an a rider. but with stiffer suspension you wll feel some in your hands there no way around it. as far as the fork spring WT the manual says .45 but FC tells me there a .46 and the manual was never changed. like i said earlyer the shim stack has no pergression to it. maybe someone else can sugest a stack for you.

The manual says its 4.4N.mm, darn i wish i could just get the stock spring rates correct! haha...anyway, i am not an expert at working on my own suspension but i think i would like to try out the Smart performance kit, can you elaborate on what it offers? I would go with the DIY kit, any special tools i will need? I have some friends who always work on their own stuff that can help me with the install process as well.

[DMauro]

4.4 nmm is 4.5 kg so its right. the new smart performance kit is for faster riders as it stays up in the stroke better than before and is stiffer. compared to stock it has a little less inital harshness but like i said wit stiffer suspension you have to feel sommething or you would just not be able to ride fast. ont thing i can say is the last time out i over jumped a table with a 10 take off and flat landed all i pictured was my wrist breaking and i servived. without harsh bottomimg. as far as tools you dont need much but i had someone put it in for me and now i dal directly with dave. give him a call 408-406-2089 and tell him dean mauro sent you and you want the new stuff i have for my 2010 kxf

[adamdf]

4.4 nmm is 4.5 kg so its right. the new smart performance kit is for faster riders as it stays up in the stroke better than before and is stiffer. compared to stock it has a little less inital harshness but like i said wit stiffer suspension you have to feel sommething or you would just not be able to ride fast. ont thing i can say is the last time out i over jumped a table with a 10 take off and flat landed all i pictured was my wrist breaking and i servived. without harsh bottomimg. as far as tools you dont need much but i had someone put it in for me and now i dal directly with dave. give him a call 408-406-2089 and tell him dean mauro sent you and you want the new stuff i have for my 2010 kxf

Is the kit you have the Del taco kit? And does he have a solution for the shock? Or will the fork kit alone most likely compliment the shock in this particular instance?

BTW, thanks again for all your help, truly appreciate it!

[DMauro]

its the new third generation del taco, we are still in testing with the shock on a new set up that i like.