2004 vs. 2005 YZ 250 forks springs

Discussion in 'Suspension' started by Bailey28, May 24, 2005.



  1. Bailey28

    Bailey28 Rookie DRN Member

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    I bought a used 2004 YZ 250 and the previous owner had it resprung and revalved for him by Renegade suspension. He weighed 145 lbs and was an "A" fast rider. I weigh 180lbs or about 190 in full gear and am a vet +30 novice. It seems that I am beating up the bike over big stuff, but over the small stuff the bike swaps and deflects. I think I am riding down in the suspension stroke where it is very stiff over the smaller things

    I bid on a set of 2005 fork and shock springs on **** and won both. I can use the stock shock spring at 4.9kg/mm but I cannot use the fork springs. I just learned on MX tech that the springs are slightly different in shape or size, the 2004 being a 4448 series and the 2005 a 4447 series . I cant imagine the dimensions changed that much from 04 to 05... The rate of the '05 springs would be fine for me at .440kg/mm.


    I wanted to try the proper springs as the previous owner said the bike was stiffly valved and softly sprung. I think the valving will be fine once I get the right springs in there. Has anyone got any hints as far as taking the fork caps off so I can change the springs when I get the correct springs?
  2. marcusgunby

    marcusgunby Lifetime Sponsor

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    the 05 yz250 fork is totally different to the 04.
  3. mop

    mop Rookie DRN Member

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    The 2004 KYB fork spring is 10mm longer than the 2005 spring. If you use an '05 spring in the '04 fork, you must use a 10mm long preload spacer. The spacer MUST be very close to the same inside and outside diameter of the spring and locate it on the top with the stock spring "hat". If it is a sloppy fit, it will misalign and ruin some internal parts.
  4. Bailey28

    Bailey28 Rookie DRN Member

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    Thanks, I may try using a hardened steel spacer. 10mm+ I can play with adding preload if I wanted to. I'll just be careful to use a spacer the exact diamter. Is anyone making these already?

    IF I can get or make preload spacers for the forks, the question of the day is do they:;

    A- go in under the bottom of spring closest to the fork oil seal?

    B- go on top of the spring closest to the top triple clamp?

    I searched and found that someone had smashed fork internals due to improper placement of the preload "washer"

    Will PVC in this case work fine? :blah:
    Last edited: May 26, 2005
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