crf250 enduro suspension setup
  • Kamilsamek
    Posts: 8
    Joined: Sun Aug 12, 2018 10:02 am

    crf250 enduro suspension setup

    by Kamilsamek » Sat Jul 13, 2019 11:58 am

    hey everyone, i have some questions about setting up my forks, maybe any of you could help me. my bike is a 2006 crf250r, im 65kg 175cm,  i mostly ride enduro, the suspension has stock springs 0.45kg/mm. so my question is what to do to soften the forks? for my weight the bike's suspension feels waaay to stiff, i got the clickers on full soft both rebound and compression. i just opened the forks to change the oil. should i change the mid/base valve stacks? if yes which shims should i remove? or should i go for softer springs maybe?


    my shims stacks:


    base valve:


    11  30mmx0.10mm 


    1    30x0.10


    3    30x0.10


    1    25x0.10
    1    29x0.10


    1    28x0.10


    1    27x0.10


    1    26x0.10


    1    25x0.10


    1    24x0.10


    1    23x0.10


    1    22x0.10


    1    21x0.10


    1    20x0.10


    1    19x0.10


    1    18x0.10


    SPACER 30,5mmx2mm


    1    16x0.20


    1    11x0.20


    1    12x0.10


    1    13x0.10


    1    14x0.10


    1    15x0.10


    10   16x0.10




    MID VALVE

    REBOUND:


    3    16mmx0.30mm


    1    11x0.20


    1    12x0.10


    1    13x0.10


    1    14x0.10


    1    15x0.10


    1    16x0.10


    1    12x0.10


    1    18x0.10


    2    20x0.10




    COMPRESSION FLOAT=0,35mm


    COMPRESSION:


    6    20mmX0.10mm
    4    17X0.10


    3    10x0.20
  • User avatar
    JimDirt
    Posts: 3229
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: crf250 enduro suspension setup

    by JimDirt » Sat Jul 13, 2019 4:32 pm

    What I would do is leave the stacks as is for now as I do not know how fast you are or if you are pleasure riding or racing , and go with a 0.42kg Fork Spring (0.44kg at the most) and change the Pressure Spring from 1.9kg to a 1.4kg (what I run in both my bikes) The Pressure Spring will take away some of the initial harshness , and the lighter main spring will help in overall plushness , you did not mention how much oil you have in the forks .... I would suggest starting at 370cc's (basically stock) and if needed add 5cc to each leg (thru the bleed hole so you don't have to remove the forks from the clamps) if you have any bottoming issues

    After you replace the springs , put your clickers back to stock and ride it to see how you like it , then if needed go out on the compression only (leave the rebound for now) and see if it gets better or worse , if it gets better and you stay within 15 or so clicks out , you should be fine , if you need to still go more than that , then I would suggest revalving it softer on the compression stack (I can help you with that in figuring out what to change if needed) .... but it will probably be a noticeable difference just changing the springs , remember this is a MX bike , so the suspension will not be as plush as a X will ............ The shock spring you can leave if you like , as I am sure you are using a backpack or a hydration bladder , so that will usually add 10 or so lbs to you (4kg or so) , so that will make it so you are not too soft in the back , keep your sag around 105mm-110mm to keep the bike balanced , as too little sag will put more weight on the front and make it feel harsher especially if you are going fast in any kind of roots or square edge holes , and you can run more sag off road without issues which will help with plushness.......

    EDIT:
    I wanted to add that because the stock springs are for someone heavier than you , that is part of the harshness , because the forks need to compress to open the valving , the same goes for the Rebound , as the forks need to move the rebound rod fast enough to open the rebound stacks , if the springs are too stiff , the forks will not compress fast enough to open the stacks , and you will basically be bypassing the stacks , and , you will be in the wrong part of the stroke when it does open because the springs are holding it up in the top part of the stroke all the time .... make sense ??? ..... so going with softer springs should help with most of your harshness issues ....... ;)
    02 CRF450R
    06 CRF450X
    Image
    Weiser , Idaho
  • Kamilsamek
    Posts: 8
    Joined: Sun Aug 12, 2018 10:02 am

    Re: crf250 enduro suspension setup

    by Kamilsamek » Sun Jul 14, 2019 11:49 am

    hey, thanks a lot for your reply. well that explained a lot. i already ordered softer springs (0.42) gonna put them in and see if that solve the problem. im an average rider so i dont ride veryy fast , just at normal speeds. the sag is set to 100mm, so i will try setting it to 105-110mm. i was running on the lowest possbile oil level, 320cc. well thanks again for your help.
  • User avatar
    JimDirt
    Posts: 3229
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: crf250 enduro suspension setup

    by JimDirt » Sun Jul 14, 2019 6:06 pm

    hey, thanks a lot for your reply. well that explained a lot. i already ordered softer springs (0.42) gonna put them in and see if that solve the problem. im an average rider so i dont ride veryy fast , just at normal speeds. the sag is set to 100mm, so i will try setting it to 105-110mm. i was running on the lowest possbile oil level, 320cc. well thanks again for your help.
    The oil acts as a dampener mainly for bottoming resistance , the issue is , when you add or remove oil , it does nothing for the first 4" of travel , it really only affects mid to bottom function , so though running less oil sounds like it will give a plusher rider , it only does so from mid to bottom , and will not really affect the top of the stroke where you are finding the bike stiff , and with the stiffer springs you have , it is not allowing the forks to travel fully thru the stroke , which is what is contributing to the harshness and why going so far out on the clickers is not having much effect on the harshness , which is why I recommended just running the stock cc's , you can go a little less , but I would not go less than 350cc's , because part of the function of the outer tube oil is for lubrication , the less oil , the less lubrication , as well as the less oil to absorb the shavings/particles of the bushings , etc. , which is why when you change oil , the inner chamber oil is usually clean , and the outer chamber is gray , its gray because of the coating that is wearing off the bushings as the forks go up/down , if you run less oil you get more contaminants in less area , that is why when you have a seal leaking , besides outside dirt contaminating everything because it is getting past the leaking seal , but , you will find that because of the decrease of oil volume , everything is just dirtier and it actually causes more wear on the seals and tubes themselves (scratching the chrome surface) than if the oil level was higher .......The springs (both outer and cartridge Pressure Springs) play more of a role in initial and overall harshness than the oil does , the valving does the rest ...... ;)
    02 CRF450R
    06 CRF450X
    Image
    Weiser , Idaho
  • Kamilsamek
    Posts: 8
    Joined: Sun Aug 12, 2018 10:02 am

    Re: crf250 enduro suspension setup

    by Kamilsamek » Mon Jul 15, 2019 11:28 am

    hey, thanks a lot for your reply. well that explained a lot. i already ordered softer springs (0.42) gonna put them in and see if that solve the problem. im an average rider so i dont ride veryy fast , just at normal speeds. the sag is set to 100mm, so i will try setting it to 105-110mm. i was running on the lowest possbile oil level, 320cc. well thanks again for your help.
    The oil acts as a dampener mainly for bottoming resistance , the issue is , when you add or remove oil , it does nothing for the first 4" of travel , it really only affects mid to bottom function , so though running less oil sounds like it will give a plusher rider , it only does so from mid to bottom , and will not really affect the top of the stroke where you are finding the bike stiff , and with the stiffer springs you have , it is not allowing the forks to travel fully thru the stroke , which is what is contributing to the harshness and why going so far out on the clickers is not having much effect on the harshness , which is why I recommended just running the stock cc's , you can go a little less , but I would not go less than 350cc's , because part of the function of the outer tube oil is for lubrication , the less oil , the less lubrication , as well as the less oil to absorb the shavings/particles of the bushings , etc. , which is why when you change oil , the inner chamber oil is usually clean , and the outer chamber is gray , its gray because of the coating that is wearing off the bushings as the forks go up/down , if you run less oil you get more contaminants in less area , that is why when you have a seal leaking , besides outside dirt contaminating everything because it is getting past the leaking seal , but , you will find that because of the decrease of oil volume , everything is just dirtier and it actually causes more wear on the seals and tubes themselves (scratching the chrome surface) than if the oil level was higher .......The springs (both outer and cartridge Pressure Springs) play more of a role in initial and overall harshness than the oil does , the valving does the rest ...... ;)
    thanks for your reply again. ok now i understand a bit more how forks really work. but got another 1 question, you said the outer oil should be cleaner than the oil in the cartridge, but on my forks both inner and outer oil's were grey colour. also what i saw is that when i flip the cartridge upside down and try to move the rod, oil is comming out from bleeding holes(the 2 opposite holes on the side). is it normal? or some seal is leaking?
  • User avatar
    JimDirt
    Posts: 3229
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: crf250 enduro suspension setup

    by JimDirt » Mon Jul 15, 2019 1:06 pm

    OK , as far as the oil being cleaner (you got it backwards) , I said the oil in the Cartridge should be cleaner than the outer oil , not the other way , as the cartridge "should" be sealed , so if you found gray oil in both areas , it could mean 2 things ..... 1 , The oil in the inner Cartridge was never changed before and its just old and dirty from wear from the bushings on the Free Piston ..... OR , one of the seals is leaking , as there are 2 seals that can leak , there is the seal where the Rebound rod enters the Cartridge , which if it was taken completely apart and the Rebound Rod removed , then most likely the threads from the rebound rod (which are very sharp) have cut the seal and it is leaking there because no one used Thread sealing tape (white plumbers tape) on the Rebound Rod threads before pushing it thru the Cartridge to remove it , usually indicated by oil seeping down the rebound rod after it has been removed from the outer tube and the Cartridge has not been disassembled and even after wiping it down , oil is seeping down the rebound rod while it is sitting upright ......

    And/or the Free Piston Seal is leaking (the seal around the piston , where the valve stack is) is leaking , usually indicated by the Cartridge not fully extending , and when you compress it manually , it does not extend all the way or sucks back in a bit , either of those conditions will cause the Rebound Rod to suck back in or not extend fully when compressed or sitting under its own weight against the workbench , along with the main O-Rings , could cause contaminated oil to enter the cartridge , any of which means you need to replace the seals (I can walk you thru either procedure)

    This is where the Free Piston Seal is located:(not the O-Ring you see but in the center of the Free Piston where it goes around the shaft)
    Image

    The oil coming out the 2 weep holes is normal , that is oil that has splashed up from the outer chamber , ....... Unless ....... it is oil leaking past the O-Ring for the Fork Cap Assembly (where the clickers and valving are)
    02 CRF450R
    06 CRF450X
    Image
    Weiser , Idaho
  • Kamilsamek
    Posts: 8
    Joined: Sun Aug 12, 2018 10:02 am

    Re: crf250 enduro suspension setup

    by Kamilsamek » Tue Jul 16, 2019 10:59 am

    OK , as far as the oil being cleaner (you got it backwards) , I said the oil in the Cartridge should be cleaner than the outer oil , not the other way , as the cartridge "should" be sealed , so if you found gray oil in both areas , it could mean 2 things ..... 1 , The oil in the inner Cartridge was never changed before and its just old and dirty from wear from the bushings on the Free Piston ..... OR , one of the seals is leaking , as there are 2 seals that can leak , there is the seal where the Rebound rod enters the Cartridge , which if it was taken completely apart and the Rebound Rod removed , then most likely the threads from the rebound rod (which are very sharp) have cut the seal and it is leaking there because no one used Thread sealing tape (white plumbers tape) on the Rebound Rod threads before pushing it thru the Cartridge to remove it , usually indicated by oil seeping down the rebound rod after it has been removed from the outer tube and the Cartridge has not been disassembled and even after wiping it down , oil is seeping down the rebound rod while it is sitting upright ......

    And/or the Free Piston Seal is leaking (the seal around the piston , where the valve stack is) is leaking , usually indicated by the Cartridge not fully extending , and when you compress it manually , it does not extend all the way or sucks back in a bit , either of those conditions will cause the Rebound Rod to suck back in or not extend fully when compressed or sitting under its own weight against the workbench , along with the main O-Rings , could cause contaminated oil to enter the cartridge , any of which means you need to replace the seals (I can walk you thru either procedure)

    This is where the Free Piston Seal is located:(not the O-Ring you see but in the center of the Free Piston where it goes around the shaft)
    Image

    The oil coming out the 2 weep holes is normal , that is oil that has splashed up from the outer chamber , ....... Unless ....... it is oil leaking past the O-Ring for the Fork Cap Assembly (where the clickers and valving are)
    hey, thanks for your reply. yes i understood the thing you said before that the inner oil should be cleaner. mine was both out and in same colour, grey. i services the forks myself before 45hours so i guess it was too much, should have changed the oil earlier. i changed seals and bushings last time. so about the oil leaking from the cartridge. well when i push the rod in and out i dont see any oil signs on the rod, so i guess that seal is okay. so probably it will be the other seal which you showed me on photo? last time when i serviced forks, when i was moving the rod it was going back itself (rebounding). now it seems like its not going back, i mean i move it and it just stays there. gonna change the seal, put softer springs, put some fresh oil and we will see :) thank you so much for your help.
  • User avatar
    JimDirt
    Posts: 3229
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: crf250 enduro suspension setup

    by JimDirt » Tue Jul 16, 2019 1:49 pm

    No problem ..... Glad to help .... Yea it is most likely the Free Piston seal , and just as a "know" you can go all season without doing anything with the inner cartridge and it should still be clean , so definitely some leaking going on , basically the outer oil is mixing with the inner if bushings are fairly fresh , so replace the Free Piston seal , and if you have done it before (you have to drill the peens out for the outer seal removal) then I would go ahead and replace main cartridge seals while you have it down , especially if you pulled the Rebound rod without taping the threads with Teflon Tape (this is a must do) ... if I remember right , its like $40 for all 4 seals from Race Tech , so might as well do them all while its down , then you are good to go ....

    I usually only service my inner once a season (over the winter when I am done riding) unless I am changing around the stacks during riding season for some reason , which I do from time to time , otherwise , I will just change the outer oil once during the season and once at the end , as I usually get about 2 actual MX track riding hours per day Sat/Sun almost every weekend .... Am heading out of town (275 miles each way) to ride a cool track in the middle of nowhere in Oregon this coming weekend , leave Friday , and be back sometime Monday (I will be 60 in Aug.) , but still only do 1 service in the middle of the season , and one during winter , usually outer is dirty , but inner is clean , and it basically gets the whole season ... I just changed ALL bushings and ALL oil about 4 weeks ago , including the shock and recharging it , so I should be good till winter ................
    02 CRF450R
    06 CRF450X
    Image
    Weiser , Idaho

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