2009 crf450 fork valve stack help


14 replies to this topic
  • DK_134

Posted July 25, 2011 - 03:42 PM

#1

Hey guys,
I decided to take on the task of revalving my own suspension. I have a 2009 CRF450R. I have already upgraded to 0.48 fork springs but still bottom out on hard landings and feels very harsh over braking and acceleration bumps. I am 5' 10", 180lbs, B/intermediate class rider in Canada. The shock feels fine and the stock shock spring is ok for my weight so I am just servicing the rear. Anyone have any advice on how I should modify my fork valve stacks?

Dallas

  • Rmzben

Posted July 25, 2011 - 09:46 PM

#2

how often does it bottom you have to allow 1 or 2 bottom outs a lap your not going to have it plush and stop it from bottoming completely.also alot of the problems come from the rear on the 09 maybe an aftermarket rear linkage arm may transfer some of the weight to the rear more.

  • DK_134

Posted July 26, 2011 - 05:09 AM

#3

I already have a ride eng. link. I guess it would bottom 2-3 times a lap depending on the track. One of the local practice tracks is pretty rough and has some big jumps. We mostly ride sand around here and it gets rough. I'm more concerned with getting it plush over the choppy stuff. I also ordered some 1.7 fc pressure springs.

  • 2svs4s

Posted July 26, 2011 - 06:59 AM

#4

I think that you will find the ICS lighter spring does make things softer but you may find the bottoming to get worse. The stk ICS is good for your weight.

What is your low speed adjuster on?

  • DK_134

Posted July 26, 2011 - 07:19 AM

#5

low speed adjuster is 10 clicks out

  • jjy130

Posted July 26, 2011 - 08:27 AM

#6

I know you said the shock feels ok, but it can be much better and it is making your forks feel soft on big hits. There is another thread a few down about 09 shock stack with a guy similar in weight to you who considerably softened his shock. I also have the 09 and in stock form the forks were stiff up top and borderline soft on big hits for me. I softened the shock and now I was able to soften up the forks quite a bit and bottom less just because the shock is working with the forks now instead of forcing all of the weight to the front end.
First step to fixing your forks is run a stack close to this for shock
(6) 44x.2
36x.1
30x.1
(6)42x.15
40x.2
38x.2
36x.2
34x.2
32x.2
30x.2
28x.2
26x.2
24x.2
(2)22x.3

keep rebound the same

after doing the shock run the fork base valve like this and keep mid valve stock
(13) 32x.1
30x.1
28x.1
26x.1
24x.1
22x.1
18x.1
14x.25

free bleed
remove 1 of the largest shims, I can't remember the size off hand
also start at 340cc of oil and add more if necessary after riding.

Again, this setup for the forks will only work if you do the shock, with the stock shock stack you will be bottoming a lot on the forks with this setup. Also I would try with and without the rear link, I don't feel the link is needed once the valving is done.

  • DK_134

Posted July 26, 2011 - 08:50 AM

#7

thanks a lot...I'll try this setup out. when you say free bleed is that the "low compression stack?"

  • jjy130

Posted July 27, 2011 - 08:10 AM

#8

on your base valve there is the compression stack and then above that there is a large washer and above the washer is the "free bleed" stack as I call it. It is a small stack that tapers the opposite direction from the main stack. It controls the oil that flows through at low speeds before the main stack comes into play. You may need some slight fine tuning from these settings but I think you will be very pleased with this setup.

  • pope610

Posted July 27, 2011 - 07:33 PM

#9

jjy130, where are you setting you clickers with this valving? thanks

  • jjy130

Posted July 28, 2011 - 08:25 AM

#10

I'm running all of my clickers around 12-15 except the fork rebound I have around 4 now, but I would suggest you starting at 8.(I could probably benefit from adding a shim in the rebound stack in the forks) and the high speed adjuster on the shock at stock setting, I think it was somewhere around 1.5 turns and line up the dots. Let me know how you like this setup and don't be afraid to experiment. I redid my shock I think 4 times and the forks 3 times so far and slowly progressed to stacks similar to what I posted but a little softer(I'm 155 pounds). Any other questions on working on the shock? I had a few hang ups that took me a while to figure out how to get through while working on it.

  • DK_134

Posted July 28, 2011 - 08:33 AM

#11

I have the shock all done and charged up, bled out with no problems. Doing the forks tomorrow night, hopefully riding on the weekend.

  • DK_134

Posted August 02, 2011 - 05:20 AM

#12

went riding on sunday and yesterday...suspension works great...haven't tried it with the stock linkage arm yet but its working really well right now. The forks used to bottom out on singles and big sand whoops but now its only on big hits like if I come up short or over jump something big. thanks for the help jjy130.

  • jjy130

Posted August 02, 2011 - 08:29 AM

#13

I'm glad to hear the positive feedback. It may work good with the aftermarket linkage, but I just revalved mine and couldn't be more pleased. I don't think most people realize how stiff the stock shock is which forces all the load on the forks. Again don't be afraid to experminent more with the stacks, depending on your style and speed you might benefit from removing another one or two of the 30mm shims in the forks and another 44 from the shock, but I think the stack you're running is very close what you need. Glad I could help.

  • Shawn_Mc

Posted August 02, 2011 - 04:07 PM

#14

(13) 32x.1
30x.1
28x.1
26x.1
24x.1
22x.1
18x.1
14x.25


No Cross over?

What was the stock stack?

  • jjy130

Posted August 03, 2011 - 08:36 AM

#15

stock is the same except there's (17) 32.1 A crossover might be a good idea, but I ended up at a stack similar to this but a little softer for my weight and am pretty happy with it myself. I might try adding in a crossover after a few more rides to try out my current setup. I had bigger problems that I wanted to get sorted out on mine before adding the complexity of multi stage stacks and this setup along with the shock makes the stock settings feel awful.





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