front forks WAY too stiff, suggestions.

Joined
Dec 25, 1999
Messages
41
Likes
0
#1
I took my CR for my first ride yesterday. It is great! Has great power and is very fun to ride.

The rear suspension is perfect, but the front is way too stiff. By stiff I mean that I used only half of its travel the whole time I rode the bike yesterday(when I stopped I looked at how far down the dirt was pushed by the seals). It is too rough. Every log I hit sends all the shock right to my arms.

How can I make my Suspension softer besides buying softer springs? There are no shims/spacers in the fork. There is NO SAG. When I sit on the bike it goes down maybe 2mm. I am using 5wt oil that has just been put in. Oil level is ~90mm.

I don't think it has to do with the compression damping because it has no sag.

Thank you.

P.S. I have a 96 CR250 with inverted forks.



------------------
motor86
85' KDX200(mine-for sale) 96' CR250R(mine)  81' YZ125(Dad's)  81' CM400 (my street bike)
Motor86's home page
 

Sage

dirtbike riding roadracer
Joined
Mar 28, 2001
Messages
621
Likes
0
#2
90mm is a bit high for woods riding try dropping it 10 to 20mm or maybe 30mm if your a light weight, open the compression up, it has nothing to do with your sag and make sure that the forks are centered & not binding, to check this loosen all pinch bolts at the axel and pump the front many times with the front brake on, retighten the pinch bolts. Also make sure the rebound adjuster is not closed or close to closed, it will have a slight effect on the compression circuit.

------------------
Sage Wilkinson, KDX Link 1
 

Jeremy Wilkey

Owner, MX-Tech
Joined
Jan 28, 2000
Messages
1,453
Likes
0
#3
How much do you weight? The pinch bolt idea seems very good. I'll be posting an article about tightening forks in place and wheel isues later today.
Regards,
Jer

------------------
"Danger is one thing but danger combined with long periods of suffering is quite another." Sir E. Hilary
wilkey@mx-tech.com
 
Joined
Mar 11, 2001
Messages
136
Likes
0
#4
I am having the same problem with my '97 KX250 forks. There is no sag whatsoever. When I sit on the bike the forks don't compress at all. The shock compresses normally. The forks feel ok when riding except in slow tight stuff, then they don't compress much at all. I have had the suspension revalved front and rear and new fork springs for my weight (140 lb)and the forks are raised in the triple clamp to the second line on the forks. I loosened the triple clamp bolts to make sure its not pinched and there's no difference. The fork oil is Kayaba 01 oil at the minimum possible level listed in the manual (can't remember offhand what mm level it is) I don't know what to do next. I'm planning on changing the oil to BelRay lightest weight and see if that helps. Any suggestions will be GREATLY appreciated! Thanks.

------------------
 
Joined
Dec 25, 1999
Messages
41
Likes
0
#5
If I took out 20mm of oil would that have a big affect on it? I weigh 140-150lbs. I have adjusted the pinch bolts earlier but I will do that again tonight and try it.

What would be a good spring for my weight?

Thanks for the replies.


------------------
motor86
85' KDX200(mine-for sale) 96' CR250R(mine)  81' YZ125(Dad's)  81' CM400 (my street bike)
Motor86's home page
 
Joined
Dec 1, 2000
Messages
42
Likes
0
#6
Moto86
Suspension setting can be a long and time consuming task.I would be happy to help but would like a little more information.

1.What spring rate are in your fork now.
2.What is the level set at now.
3.Does your weight include riding gear.
4.Is your rear sag set.
5.Are your fork legs rasied in the tripple tree any at all.
6.When was the last time the oil was changed.
7.are there any pre load spacers in the fork now.
8.What is the compression and rebound set to front and rear.

If I remember correctly you have a cr 250 with KYB fork.You can email me the information and I will give some thought to your problem and see what I can come up with.

------------------
it dont hurt till the bone shows.

2001 YZ 250

[This message has been edited by yamadawg (edited 04-10-2001).]
 

Jeremy Wilkey

Owner, MX-Tech
Joined
Jan 28, 2000
Messages
1,453
Likes
0
#7
This is not some complex issue.. It's most likely just an assembly related detail.. When he changed his fluid is not likely going to cuase that much trouble!

JEr

------------------
"Danger is one thing but danger combined with long periods of suffering is quite another." Sir E. Hilary
wilkey@mx-tech.com
 

marcusgunby

Lifetime Sponsor
Joined
Jan 9, 2000
Messages
6,450
Likes
2
#8
Sounds like a stiction problem, i would recommend new seals and bushes its amazing how much muck can get past the seals.

------------------
 
Joined
Dec 1, 2000
Messages
42
Likes
0
#9
Jer,
After reading motors original post I was under the impression that he has never ridden this bike before.If the fluid is old cant this cause a problem with the fork?I just did a friends fork off his 99 cr 500 and the fluid was very nasty and gloppy.He was complaining they were to stiff also.Wont know till this weekend if changing the fork oil helped or not.I was also trying to figure the weight of the oil that is in the fork.

------------------
it dont hurt till the bone shows.

2001 YZ 250
 
Joined
Dec 25, 1999
Messages
41
Likes
0
#10
Sorry I couldn't get back to you sooner. I have work after school until late, and then homework, so I get about 15 minutes of free time a day (when I am driving my truck to work and school). Here is what you asked for yamadawg.

I do not know what the current spring rate is in the bike now.
The oil level is 90mm.
145 lbs with gear
The rear sag is good and I like the way the rear suspension feels.
The forks are set in the tripple clamps at the stock position.

I just rebuilt these forks before my first ride on this bike ever. I bought it with bad seals and I knew I could fix them for $50. I knocked $300 off the price of the bike by telling him about the leaking forks. The seals are new, and the oil is new. It has 5wt oil. There are no preload spacers.

The clickers were adjusted to the stock setting after the rebuild.

Yamadawg, rebuilding the fork went good. It turned out great and they don't leak at all now. Thanks for talking to me in a previous email about them.

------------------
motor86
85' KDX200(mine-for sale) 96' CR250R(mine)  81' YZ125(Dad's)  81' CM400 (my street bike)
Motor86's home page
 

MACE

Lifetime Sponsor
Joined
Nov 13, 1999
Messages
441
Likes
0
#12
Originally posted by motor86:
There is NO SAG. When I sit on the bike it goes down maybe 2mm.
This sounds like something is mechanically wrong.

Check the free length of the springs. I wonder if the springs are not the right ones for that fork.
 
Joined
Dec 1, 2000
Messages
42
Likes
0
#13
Moto,
From the sound of things the spring rate on the fork may be to stiff for your weight.If you knew the weight of the guy you bought the bike from you could probly get a good idea of the rate.With your weight I would think you could go with .039 or lighter on your spring rate.You could also change the oil level to be between 120 and 135mm if you were to stay with the rate that you already have and soften up the compression and slow the rebound some.If you decide to adjust the clickers make small adjustments so you can tell if it is makeing things better or worse.I will continue to think about this and come up with some other suggestions..Good Luck and I hope that this helps.

------------------
it dont hurt till the bone shows.

2001 YZ 250
 
Joined
Dec 25, 1999
Messages
41
Likes
0
#14
I redid the seating of the front axle tonight(loosening right pinch bolts, pumping front end with brakes on). I was unable to ride it due to work to test it out.

The free length of the springs is 18.5"
The manual says they should be 19". I didn't want to replace them when I found this out since I had no idea if this was the correct spring rate. I wanted to ride it and see what I thought before I started modifying the fork to fit me.

I am sure, now that I think about it, that the springs are way too stiff for me. The guy I bought it from weighed 220 lbs. He didn't have any revalving done to it that I know of.

When I sit on the bike and rock the bike back and forth with the front brake on, I find that it goes down pretty hard for the first 3.5" and then it gets really hard to push down. I know that all the internals are free and nothing is binding since I just had the forks all apart and tested them before I put them back together for binding.

Thanks

------------------
motor86
85' KDX200(mine-for sale) 96' CR250R(mine)  81' YZ125(Dad's)  81' CM400 (my street bike)
Motor86's home page
 

Jeremy Wilkey

Owner, MX-Tech
Joined
Jan 28, 2000
Messages
1,453
Likes
0
#15
My whole point was not that servicing the fork was not important but rather likely not the issue. Even if the rate is so stiff free sag would yeild more sag under the bikes weight. It is a mechanical issue..

Hum...

Jer