[mossman77]

I just replaced the rear spring on my '07 CRF250X with a 5.9kg/mm Eibach spring. Now it feels like the front is too soft. I haven't set my sag or even ridden the bike yet, but when I sit on it and shift my weight forward, the front end dives (understandably). I entered my numbers into the Race Tech website, and it recommends 0.41kg/mm springs for the forks, which is the stock spring rate. Do I simply need to adjust my clickers to stiffen up the compression? I currently have them set to the middle position (12 clicks?)

[JimDirt]

That is weird that it recommends that rate , i personally would suggest a 0.49 for your weight , you are about my size and i use a 0.52 , but i re-valved my bikes really soft and i am a bottom B top C rider (i am going on 56 , so slowing with age) , so slightly softer would be better for stock valving

I think you would be happy with something between 0.47 and 0.49 , what i would do is hit up the local suspension shops and see if they have any cheap pull-off stock 450R or 450X springs , you should be able to get them real cheap , and throw them in and see if you need more or less in rate , this way your not out a lot of money , and if it does what your looking for , then your good to go

Basically the springs are what hold the bike up , and allow the valving to work WHEN it should in the stroke , so with too soft a spring the bike will actually feel harsher than with stiffer springs (to a point) , so your looking for a balance between comfort and performance , your skill level makes the rate selection different for each rider of the same weight , hope that helps some

[Old Dude]

I fit your profile as well. I have 450X springs in my 250X. They work great for me. Mine is set up for desert type terrain and riding.
O.D.

[mossman77]

I fit your profile as well. I have 450X springs in my 250X. They work great for me. Mine is set up for desert type terrain and riding.
O.D.

What are the spring rates?

[JimDirt]

Stock 450X spring rates are 0.47/5.5 (fork/shock)

[mossman77]

Stock 450X spring rates are 0.47/5.5 (fork/shock)

Thanks. Hopefully I can dial in the proper amount of preload with the 5.9kg spring. I put the spring on, but haven't had a chance to set my sag.

[JimDirt]

5.9 rear , what about front ?? , if you just replace the rear with a stiffer spring and leave the front soft , the bike is going to handle like crap , its going to dive into every corner and the rear will get less traction than with the stock spring , because all the weight of the bike will be pushed forward because of the stock/soft fork springs , versus the stiffer rear spring holding the rear of the bike up ....follow ??

[mossman77]

5.9 rear , what about front ?? , if you just replace the rear with a stiffer spring and leave the front soft , the bike is going to handle like crap , its going to dive into every corner and the rear will get less traction than with the stock spring , because all the weight of the bike will be pushed forward because of the stock/soft fork springs , versus the stiffer rear spring holding the rear of the bike up ....follow ??

I follow, but the same calculator I used that gave me 5.9kg for the rear, gave me 0.42kg for the front, which is stock (0.409kg to be exact, so I rounded up). Got lucky I guess.

[JimDirt]

I would personally suggest getting at least 0.47 , or don't bother putting the rear spring on , , you would be better off with a 0.47 and the stock shock spring than the other way around , .... just my opinion

[mossman77]

So the Race Tech calculator must be WAY off???

[JimDirt]

I don't know what to say about that , it has always been "fairly" accurate for me , or in the searches i have made on it , but the 250R/X are sprung for a 155 +/- 10 lbs rider from the factory , and 450R/X are sprung for a 185 +/- 10 lbs rider , so you can take it from there , and for "Trail Riding" you can fudge a bit on the springs and still be ok as long as your maintaining lower speeds and not bottoming out everywhere or getting kicked in the rear (high speed desert riding , will yield less forgiveness to improper spring choice)

I use 0.52 fork and have 0.46 , 0.47 , 0.49 ,0.50 ,0.52 springs laying around to choose from ,(rear i have 5.3 ,5.5 ,5.8 )but found i prefer the 0.52/5.5 combo on my X and 0.52/5.8 combo on my R , but i re-valved my bikes (myself) really soft (using Race Tech kits) , so i need a slightly stiffer spring to hold the bike where it should be in the stroke because of the softer valving , i should have a 0.49/5.9-6.0 , i run 0.52/5.8 on my 450R with a Pro Moto Billet Link (i also ride this bike on the track so spring choice is more critical) and 0.52/5.5 on my 450X , with a Kouba Link (have not changed the rear spring , yet , because for the type of riding i do with it , it works ok *no big jumping*, but i will stiffen it up on the next tear down) , you should be around 0.46-9 / 5.7-6.0 (variance by skill level , faster rider = stiffer suspension)

Again , there is no if you weigh this , you use this spring , its all subject to rider input/feel and skill level and weight , a 185 lbs pro will run a 0.52 fork , where a novice 185 lbs rider will prefer a 0.46 , as the stiffer spring will beat the novice rider to death and be almost UN-rideable , but the pro rides faster so they need the stiffer spring because things happen so fast and the jumps are farther and and things are hit faster , etc

[mossman77]

The Race Tech calculator gave me 0.42 kg/mm fork and 6.0 kg/mm shock, so hopefully it's right. I already put the 5.9 kg/mm spring on and as I said earlier, the stock forks are 0.42 kg/mm. I spoke with Race Tech on the phone and asked why their calculator results said I need a much stiffer shock spring but the fork springs are same as stock, and they said because the stock shock on the Hondas is typically way undersprung. I also spoke with Eibach, and they recommended the 5.9 kg/mm rear spring (compared to 6.0 kg/mm from the Race Tech calculator), so that is consistent information. I'm gonna be pissed if it isn't right. I'll be measuring my sag this weekend.

[JimDirt]

lol , i was editing my above post when you were posting ....

The sag will be your guide as to what spring to get , but you need to balance the front to the rear or you will not be happy

[mossman77]

I put in trails/enduro, novice, and 215 lbs and the calculator spit out 0.41 kg/mm (rounded to 0.42 kg/mm) and 5.8 kg/mm (rounded to 5.9kg/mm), so this should be balanced combination, correct?

[JimDirt]

Not in my book , but who am i to say why they come up with that combo , i would say , more like 0.49/5.8 , if i were using a 0.42 fork i would want a 5.3 shock and valve accordingly , but with stock valving , i would want stiffer in the front to keep the bike from diving in corners and beating you to death in rough areas (for off road)

Think about the valving this way , when your riding thru/over rocks , ruts , logs , you want a compliant front end so it does not deflect and beat you to death in the process , you don't want it to drop into a hole on the trail and throw you over the bars because it dives

Now add a stiff spring to the mix (rear) , now you just added to the deflection , diving , and over steering because the front is way softer than the rear , in off road riding you tend to ride forward a lot , so the majority of your weight is over the front of the bike (this is of course while standing)

Added to the fact that the valving is designed to work at specific levels of compression and rebound , so certain parts of the valving (mid stroke , etc) are meant to be used when the fork is in its "Mid Stroke" , hence the term , Mid-Valve , as well as the initial part of the stroke is meant to deflect objects as well as keep the bike tracking straight and not diving into a rock or hole that would ultimately throw you over the bars , or at the least make you get a face full of dirt

So if you have too soft of springs in the forks , the forks are now already compressed into the mid stroke of the travel before you even hit the trail , so now when you are riding thru chop , you get whats called Mid Stroke Harshness , which is mostly caused by the bike riding in the mid portion of the stroke when its supposed to be in the upper part of the stroke when hitting objects , , so when you get to the end of the stroke you are still hitting stuff and the suspension has no where to go but back up , so you get beat to death in the process of trying to ride thru a rough section because the valving is not opening when it should in the stroke because from your weight with a soft spring the bike is already into the stroke before you hit anything .....make sense ???

Basically you want to keep the bike up in the stroke till its supposed to compress , going STIFFER on the spring will make the ride SOFTER because you are now riding in the proper place in the stroke for the obstacles you are hitting .... follow ??

Also , as you get faster , which if the suspension is set up properly , you will , then you will again require stiffer springs , so with stock valving , you actually need stiffer springs to soften the ride up if your not in the 155 +/- range , at the very least i would go with 0.46 or 0.47 (stock 450R/X fork springs , i think you will be much happier with the outcome


You can (up to you) , use the 0.42 , and go for a decent ride , then get a pair of 0.46 , and install them without making any other changes (you may have to readjust your sag) , and see if you like it better , i have a feeling you will not be putting the 0.42 back in after riding it with the 0.46 ...but again , this is just my opinion , i know if i put a 0.42 in my 450X , i would be hitting the ground more than i would be going forward and my shoulders and wrists would be killing me after every ride