General spring question for Jeremy

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#1
Please let me know if I am re-hashing what has already been over hashed.

Over the years, I have noticed several trends.

1. MX bikes come with increasingly heavier springs (especially fork springs).

2. MX magazines very rarely mention using lighter springs on a 250 for a lighter rider, it's always stock or heavier.

3. MX magazines sometimes suggest heavier springs for light weight pros than they do for 200 pound woods riders.

For example, my bike is an '01 CR250. The magazines, with a variety of rider weights, are indicating either the stock springs or going one step heavier. There is no way that the bike sag on this bike will be under 25mm with the lighter riders and the stock 4.9 shock spring. What gives? are they just too lazy to put the right springs on for each rider, or isn't this really necessary?

I always thought that you spring the bike for rider weight and valve it for ability and riding style.

I weigh 140 pounds without gear. I have switched to a 4.75 shock spring, but still have about 33mmm bike sag with 95mm overall sag (terminology?). Per the Honda book and Race Tech, I need a much softer shock spring.

On the forks, they seem to work ok, but maybe they would work better with lighter springs. I guess I would describe the action as controlled but not plush. The front end tends to want to push in a flat corner. I have the compression 14 clicks out, and bottoming resistance is still excellent. Oil level is stock, with stock .44 springs. Race Tech suggests about .39-.40 for my weight.

Jeremy, my questions:

1. What gives on the conflict between the "experts" in the magazine tests and Race Tech/my Honda manual?

2. Do you think it would be worthwhile to buy lighter springs?

3. How critical is bike sag, does it really have to be <25 mm?

I am certain that there are many others out there with the same dilema.

Years ago, I had 250s that I couldn't reach 4" sag on even with the spring nearly all the way loose. I am wondering now if I could have unlocked more potential from the suspention with the right spring. At the time, I was happy with the setup.

Thank you in advance for your help!

[This message has been edited by kookooformotopuffs (edited 03-31-2001).]

[This message has been edited by kookooformotopuffs (edited 04-01-2001).]
 
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#2
Hey KOOKOO,
I have a similar dilema and the same confusion.
I just purchased a '00 WR400F, all stock with about 10 hours total time. I have gradually backed off all the compression setting to the minimum and it is still to stiff. I'm looking for a plush old guy ride like I had on my last bike, a '81 XR250R.

The information in my service manual and most of the information I read and hear seem to conflict significantly. The service manual says soften the springs, race tech says soften the springs and re-valve everything, the magazines say harden the springs and leave the shocks along. I don't know what to believe and don't want to spend a grand to find out.

Does anyone know a way to understand what the ride will be like after I soften both the front and rear. I'd like to test some different options before deciding what to do.

I'd appreciate anything anyone may have to say towards this subject.


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Old guy who putts around behind the KX_kid on a '00 WR400FM,
 
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#3
Dirtbikedad, it's good to hear that I'm not alone! If you decide to go with a lighter spring or springs, keep in mind that you may be able to find stock springs from another year/model and save money. The factories do a lot of spring rate juggling, and many of the springs are interchangeable other than the rates. That's what I did on my rear spring, but I think I still need a softer one.
 
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#4
KOOKOO,
Thanks for the info.

Do you know how I can find the spring rate and interchangability information I need to decide what other springs may work? Are there charts available?

Jerry

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Old guy who putts around behind the KX_kid on a '00 WR400FM,
 
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#5
I'm not sure where to find info on springs other than magazines/dealers/word of mouth. Keep in mind that you want to go at least .02 Kg/mm difference to be worthwhile (otherwise you probably won't even be able to tell.)

Today I ended up turning my fork compression all the way out and messing with the other clickers, and the forks actually worked pretty good. Still wondering if springs would help.

Jeremy, are you out there? Still waiting for a reply.
 

zsr

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#6
If I might add the weight of my experience to your argument. I too noticed how the magazines argue for stiffer springs to give a plusher ride. Being stupid, I tried it on his CR125 1n 1998. Several weeks (& crashes) later, my son could take it no longer. We spent half a day at a track with a suspension guru. How he laughed. He didn't just go back to the stock springs, he went one lighter, front and rear, (my son at that time was about 150lb and top 6 club rider) as well as revalving. The best tip he gave me was that whatever sort of riding you do, however fast you are, the suspension should just (only just) bottom out on the most demanding section.

Consequently my son learnt to turn a bike so tightly it was beyond the comprehension of those that saw his improvement, whereas before, even on the stock springs, he would constantly run wide.

Soft may not be 'cool' but unless you plan on casing a 100' double, I think you'll be quicker.

Now if only we could sort this poxy 250 !! :)

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98 CR125 01 CR250 99YZF R1

Thanks to: Motorex / D.I.D. / Vesrah / YES Helmets
 
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#8
Uhhh, if that is true and this is Jeremy's forum, could DRN or Jeremy get someone to fill in? That would be great...
 
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#9
you can find charts on what rates come on what bikes and what springs will interchange on what models in the White Brothers Off-Road catalog
 

Sage

dirtbike riding roadracer
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#10
This topic will require more typing than I can handle but I'll give it a swing, I tend to go softer on the spring and raise the oil level to avoid bottoming out, when I say softer I take a race tech spring chart and go 1 to 2 softer for your weight. if it still too soft add a bit of compression valving. for some reason it seems that everyone wants to think they need big truck springs in their forks & shock. all the suspension that I've done and redone for people that have sent them out to the "truck spring" people, no names will be said, work better for less. I like suspension to take the small stuff and the big hits and remain firm but still work. Plush not Mush, I saw that on a Race Tech add and thought it was cool and pretty much summed up what I wanted to say.

As for the mod for this forum, I've been looking for a post for a few weeks now and havent seen one? hopfully he's got so much work he can't get away, I stop by when checking my mail & try to help out as long as I don't have to type this much. Also it's hard to help out over the computer because there a lot to be said on the suspension topics. Feel free to call if you need help or advise on a long winded subject. Sage.

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Sage Wilkinson, KDX Link 1
 
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#11
Thanks for the help, guys! My cr handles pretty good for a 250, but I still am thinking that the front end isn't settling into corners like it should (heavy springs).

Until I get springs, I thouhght about cheating a little by bleeding the air out of the forks while they are slightly compressed. Has anyone tried this? Remember, back in the day we did the opposite, that is, we added air pressure to yield a heavier effective spring rate.
 

MACE

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#12
We had some fun with this subject in a previous post:
http://dirtrider.net/ubb2/Forum24/HTML/001356.html

I'm an open class rider weight wise (over 250) and all the pros say I need real heavy springs.

I'm not so sure.

Well I have my stock .44s a pair of .46s and some .48s (off an aircraft carrier catapult I think...) that I'm planning to lab rat.

If my buddy doesn't dog me, I'll try the new .48s Sunday. I'm not testing side by side right now, but I'll try to report any strong indications.

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MACE

One night I was layin' down,
I heard mama 'n papa talkin'
I heard papa tell mama, "you let that boy MOTO,
it's in him, and it got to come out..."
 

JPIVEY

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#13
I don't know if this will help but race tech
has a chart, enter your bike and weight and you can print out their recommendation

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Shaw520

Damn Yankees
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#14
Keep in mind guys, plushness starts at the top of the stroke, If your running too soft spring rate, and your riding halfway into the stroke, its not going to feel plush. JM2cents.

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Faster Bikes, Younger Women, & Older Whiskey
AMA
BRC
 

MACE

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#15
Originally posted by MACE:

If my buddy doesn't dog me, I'll try the new .48s Sunday. I'm not testing side by side right now, but I'll try to report any strong indications.

AHRRRG! He dogged me. This may be my last post because I feel like I'm about to burst into flame.....lmsdflm;lds /c