Im new to suspension so please bear with me....

[Irish MXer]

I own a 00CR250 and I am 6'5 250lbs. I ride on stock suspension and I need some help setting it up for me. I know that I am way above the target weight for this bike but I need some better setttings. The clickers are at stock settings, can yall give me some advice on what I should do to make it stiffer, and more resistance? I come off a 89KX125 so no matter how bad the suspension cannot feel harsh to me, so give me any advice, although I am limited if it requires any dissasembly.

Thanks for your time,
Irish MXer
00'CR250

 

[avlehtine]

If you want to get it anywhere near good, you _will_ need stiffer springs. If you want to do your best with what you have, first set sag (many threads on this forum, you will have to put more preload on the spring than is healthy).

You also want to increase compression damping, I think you have the fork compression at the bottom of the forks (screws), so screw them in a whole bunch of clicks (about 5 to start with), and the compression on top of the rear shock reservoir. Screw in the large nut-like thing at least half a turn and the screw in the middle again a lot of clicks.

The suspension is NOT meant for a 250 lbs. guy. To get it somewhere perfect you will need a revalve in addition to the stiffer springs.

All in my opinion, of course.

 

[Irish MXer]

Like I said I am a suspension newbie. I dont really have any problems with the fork, I am just looking to ajust the rear, I dont know how many clicks I should turn the screw on my suspension, I dont really know what it does except make it a little stiffer when I turn it clockwise. Any help would be appricated.

Irish MXer
00'CR250

 

[JTT]

I agree with avlehtine, you will definitely need springs, I am 190lbs and I had to go stiffer on both ends of my '00 CR250. You will find that the ride is MUCH more plush with the right spring.

As for settings, the small screw on the top of the shock is the Low speed compression, the larger, hex nut in the same place is the High speed adjuster, the rebound is located at the bottom of shock (down by linkage). Check out Jer's site (MX Tech) for tunig details, it's quite good, at least to get you started.

JTT

ps. You can turn the screw as much as you want, and should, you can always return it to original position.

 

[Irish MXer]

Thanks for the help JTT, I will look into stiffer springs, How much will that end up costing me? Also wich company offers springs for someone as big as me? I have a feeling this will be like bubba needing ford light truck springs

I see all these differnt rates, wich one is right for me?
Thanks guys,

Irish MXer
00'CR250

 

[robmann]

Irish MXer,
I would recommend .47 to .48 for the front and 5.4 to 5.6 for the rear

Rob Mann

 

[Irish MXer]

Thanks rob, How much am I looking at to have my local shop do this for me? If I do the back spring will it effect the way the bike acts in the air? Will I want the front redone after the back? Wich is more important?

------------------
Irish MXer
Mike McCasland
00'CR250

 

[robmann]

Irish MXer ,
You should contact your local dealer and they should be able to give you a accuate price to install the fork springs, the rear you should be able to do yourself. In your case I would do both at the same time, to keep the bike balanced.


------------------
Good Luck
Rob Mann

 

[Jeremy Wilkey]

Irish,
.48 is too light. I would go with a .50 and the 5.8 in the rear.(Your a big guy and you will need that rear spring to keep the extra weight (That will be placed farther back on the bike up.) Get what you need the first time and you will be happier for it!
Regards,
Jer

 

[robmann]

Jer,
What weight do you consider the stock springs good for?
Also would you consider .01 kg/lb a good estimate for the slope of a rear spring curve? If not then what do you consider a good estimate.

 

[Jeremy Wilkey]

Rob,
Are you laying in the weeds trying to prove your big "engineering Degree".??. Nice...
I don't even know why I waste my time..

As for the slope, the linkage on a CR requires a .008 slope. I'll let you put your engineering skills to work so you can do the math...(Simple y=mx+B )will work but point slope form is handy)O yeah I add .2kg/mm for a rider over 6 foot 2 inches..

Have a good one!

Regards,
Jer

 

[yzguy15]

Can you guys please stop fighting? I like it here with two suspension experts. Both of you know your stuff. BTW, those formulas aren't stuff you learn in Engineering, that's just algebra (I learned it last year).

Now to my real question. If I'm 5'10" and 210lbs., do I need stiffer springs? Also I'll throw this curve in at ya: I like my suspension a little softer since I only ride in the woods and don't jump much. Does this factor into your response? and Does that mean that I need to change my springs at all?

 

[robmann]

Jer,
I just wanted to see what your reasoning was that he needed a 5.8 thats all, my curve has a slope of .0065 but for quick and dirty calculations I use .01, I just think that 5.8 will be to stiff.

Rob Mann

 

[Jeremy Wilkey]

YZGuy 15,
Its called sarcasm SP and my collogue should have more than that comming.. I really have tried to be nice, evry now and then I rise to the bait and join on the mud throwing band wagon as he so despertly needs me to ....

Anyway yes your questions, I would change to a set of .44's and a 5.0 for your rear.. Springs have little impact on plushness my freind so you will not exsperice harsh suspension for that reason... My server timed out so I don't know if you included your ht..
Regards,
Jer

 

[Jeremy Wilkey]

Rob,
Your slop is too shallow.. your rates will not be stiff enough in the big view..

Regards,
Jer

 

[robmann]

Jer,
you need to check your math
y=mx + b yes this is the formula for a straight line
y = spring rate
x = rider weight
m = slope which you said yours was .008 for the CR250
b = y intercept

you recommend 5.0 for 210 lbs which is the same as I would recommend

5.0 = .008(210) + b , solve for b = 3.32 which is real close to my intercept 3.58

now we have y = .008 x + 3.32 for the CR 250 mine is y = 0.0065*x + 3.58 I add .3 for someone over 6' 2"

now plug in 250lbs
y = .008(250) + 3.32

y = 5.32 and you add .2 for someone over 6' 2"
and you get 5.52 hummmmmm and what did you recommend 5.8
Seems like you just want to contradict everything that I say. Just next time check your math.

This is just the engineer in me I guess...

Rob Mann

 

[MN KDXer]

Not trying to be a smart axle here, but I distinctly remember a thread from last summer, in which the 230# YZ250Man was asking if a either a 5.4 or 5.6 spring (I forget which) would be stiff enough. He had found a used spring, but was told he should have a 5.8 to 6.0 spring. Has something in suspension theory changed since then?

Now, for the engineer in ME... Should not the calculations include a base rate for the sprung weight of the vehicle itself, plus an additional increase for the rider, summing to a total loaded suspension weight?

------------------
-01 RM250
-99 KDX220 for sale
-Vet A Enduro and Hare Scramble Rider.
-Dry tech talker and "known to toss stones"

 

[Jeremy Wilkey]

Rob, Word,
Rob and I just got off the phone.. No my math is not wrong.. I was thinking YZGUY15 was on a YZ 125. I don't spell it out I'm sure that is right..

Regards,
Jer

 

[robmann]

MN KDXer,
This is all accounted for in the formula y intersept.

Rob mann

[This message has been edited by rob mann (edited 01-02-2001).]

 

[yzguy15]

Ok, Rob, is the slope not different on a YZ than a CR? If it is, what's the number? Also, does the same equation work for the forks too? I'm interested in being able to calculate this.

Jer, what's the difference if I was riding a 125? Actually I ride a 97 YZ250, does that make any difference? What will stiffer springs gain me then, if they have very little difference on plushness? And I'm 5'10", since you didn't catch that.

I must say that this is helping me out a lot, and I appreciate it.


[This message has been edited by yzguy15 (edited 01-02-2001).]

 

[ATK Lew]

It sounds to me like Jer's approach is
to "spring-up---dampen soft"; Rob's approach
is to spring maybe a little softer and dampen
a little stiffer. Correct me if I'm wrong
Now,as for the mud slinging, I can't imagine being in either of your positions.
I come to this board to learn and to test
my understanding of what I think I know.
The more "expert" opinions I get the better.

I hope you two can find a way to get along
here.

 

[Jeremy Wilkey]

MNKDXER,(After long pause..Hence Delay and redundency)
Your right and we do. Different bikes have different consideraions. These are bike weight, and linkage ratio.

Linkage ratio this is the bigone..

Linkage ratio is what impacts slope of the line..

Bike weight/size impacts/ condtions impacts point..

YZGUY15,
Well the 250 I would go .46 and 5.4 for you.. The slope is the same on the YZ but I use a diferent Y intercept.. That is private info but you can do the math!!

ATK,
Rob and I have talked and managed to peacfully resolve our issues with each other... His opion will be welcomed here.

Regards,
Jer

 

[Irish MXer]

Struck down by the Okiewan!!

------------------
Irish MXer
Mike McCasland
00'CR250

 

[Senior KX Rider]

THANK YOU

THANK YOU

THANK YOU

Well said Okie and very well done

 

[WWR]

WORD is wordless!!! Yippeeee!!!!

Anyway Jer,
Did you get my forks torn apart yet? Just a few last questions: Based on the info I gave you, what do you recommend for my rear spring? And, do you recommend I use the rubber bumper? I will be using your SBW and doing the shock myself.
Thanks,
Paul Herr