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Thread: Fork pressurization?

  1. #1
    300rman's Avatar
    300rman is offline My other user 3WW ID was Nitebiker07. Teaching quads a lesson
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    Fork pressurization?

    i need to stiffen my front forks a little bit, but i dont know how to go about doing it. people are telling me to use an air compressor and put air into them. but i dont want to mess them up.

  2. #2
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    I wouldnt put air in them. If you really want to make them stiffer get some pvc pipe that is the same diameter as the fork springs and cut it into 1-2'' sections and place the pvc between the springs. Then add some heavier weight fork oil to it, 30w oil would probably help you out alot. But you can always mess around with it and find the right size pvc and weight of oil to use.
    1986 200x- old school D.I.D wheels, Gold D.I.D X-Ring Chain, Rad MFG. Carrier, PRM Grab Bar, Pro Circuit T-4 custom, Maier plastics, 85x forks, 18x10.5x8 kenda klaw mxr's on itp steels, the money pit never ends

    2004 YFZ450 - CP 12.5:1, cam mod , gibson nerfs, hmf pipe, protaper bars + risers, dg bumper/skids, holeshot gncc's on itps, cycra handguard and more stuff to come.

  3. #3
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    No, dont use an air compressor!!!!! If you do go about the air method, use a foot pump. From my experience, a couple (meaning 2 or 3) pumps will put your forks at 8 psi, and the maximum air assist pressure is 10psi. You should do this with the front tire off the ground, so no weight is on the forks, and they are expanded fully.

    Adding heavier weight oil will make them compress and rebound slower, making them "stiffer" also, like Super90 stated.
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  4. #4
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    I would not use air at all, air has moisture in it, you don't want that in your forks.

    I don't like preloading forks that much either, you want at least a 1/4 to 1/2 inch sag in them with rider off machine.

    Just try a heavier oil 1st and only preload if you have a lot of sag.

    Best thing really is new heavier fork springs but I'm sure none are available .

  5. #5
    breastman569 is offline At The Back Of The Pack Arm chair racerAt the back of the pack
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    ive never been to kine on the pvc thing if your going to do that i would use a socket.
    1986 250R
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  6. #6
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    I've been running two inch PVC spacers in my R forks for quite a while now. I love it. Took all the sag out (sags slightly with me on it but sits without any at all with no rider which is how I wanted it). It made a huge difference and I didn't change anything else. Never thought about using sockets but that would work too. Just a little heavier.

    I agree with not adding air. Your seals will start leaking faster. At least that's been my experience. The only thing I use the air valves for is bleeding the built up air OUT.

  7. #7
    breastman569 is offline At The Back Of The Pack Arm chair racerAt the back of the pack
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    ive seen more seals blow due to raming air in there. just like dammit said i only use it to bleed the air out.
    1986 250R
    Ported Polished
    Paul Turner Head domed and milled
    Boyesen Rad Valve
    38mm carb
    Uni Air Box eliminator
    Full FMF Exhaust
    85 350X (getting there)
    86 250R (Roller/Parts Bike)
    85 Tri-Z (Parts Bike)
    85 NQ50 Spree (sick ass campus bike)
    Bikes Had
    85 200X (restored)(SOLD!)
    84 Z50R (SOLD!)

  8. #8
    oldred95 is offline At The Back Of The Pack Arm chair racerFirst time rider
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    My 200x manual says to raise the front wheel off the ground and fully extend the shocks. Depress the valve core until all pressure is bled off and then put the cap back on and thats how its supposed to run. Pressurizing the shocks could blow the seals out.
    1984 200X bored .040 over, mild port work, K&N filter
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  9. #9
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    Is there a thread on putting new seals in?
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