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  1. #1
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    e150 Spike Valve

    What exactly does the spike valve do, and how do we know if it's working correctly?

    .

  2. #2
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    It is a low pressure anti-fluid flow shim stack. As the pressure increases the shim stack opens up and lets the fluid flow.
    Pedaling in the seated postion = low pressure, and the front fork should stay locked down
    Stand and pedal or hit a bump = higher pressure and the shim stack opens up and allows the fork to work.
    To check it, pedal up a slight grade while seated and see if the fork moves more than a 2 CM. It will move slightly if the spike valve is working. Then stand and pedal, you should notice a big difference in the forks movement.

    I weight 205 so standing while pedaling with out activating the spike valve is a challenge. And this only matters on asphalt, never on the trails.

  3. #3
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    So does that mean that harder hits cause it to open up more and make the fork softer?
    Wouldn't you want the fork to have more resistance on bigger hits to prevent it from bottoming out?

  4. #4
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    The spike valve is an independent part of the rest of the forks suspension components. Go to the Spec web sight and watch all the cool videos. They are most likey on U-tube as well.

  5. #5
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    The spike valve is there to give you a bit of a platform for pedalling. It has nothing to do with bottom out resistance (which is provided by a combination of regular compression damping and the pressure in the main air spring).

    The spike valve keeps the fork from compressing too much under the influence of smaller forces - but once a larger hit occurs, the spike valve opens up to let the fork cycle through its full travel.
    If you notice your fork just blowing through its initial travel way to easy (like if it gets close to bottoming out just from pre-loading it for a hop for example), then the spike valve probably has too little pressure in it. You can top it up yourself although Spesh tell you not to mess with it. I've had good results for my type of riding (aggressive, and I weigh close to 200 without gear) running about 65-70psi. I think factory setting these days is around 55. (the higher the pressure, the higher the force that is needed to open the spike valve - which translates to a rougher ride as a side effect, since you need a higher force event to access the main part of the fork's travel).

    If any of that made any sense....

  6. #6
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    Quote Originally Posted by forker
    So does that mean that harder hits cause it to open up more and make the fork softer?
    Wouldn't you want the fork to have more resistance on bigger hits to prevent it from bottoming out?
    like these guys are saying , you want the spike valve to open and let the fork work and be supple.

    now a motorcycle you want alot of high speed compression to have damping controll -( and the mc gets harsh also --but you have to have it because of the weight and the velocity forces)
    but on bicycles the high speed damping would always ramp up way to quickly and the dam thing would always be way way harsh and it would rip the bars out of your hands, because the bicycle is so light .

    that is why this e150 is really a good working fork ---it is smooth and not harsh --because it bleeds off the high speed compression.

    there are many ways you can controll bottoming if that is a problem ---

    i run 60cc's of oil in my fork outters and 2cc's of oil in my air sleeve in my shock --to controll the bottoming for me ----( even tho you are not susposed to )

  7. #7
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    The Spike valve is a high speed compression circuit, it is a spring backed plate that when the fork reaches a certain high speed compression frequency the plate opens up and additional oil is allowed to flow.

    In the damper cartridge there is a piston seperating the air charge from the pure oil. We recommend 50 psi in this air chamber. Pressurizing this chamber above 60 psi affects the suppleness of the fork. If your objective is to add additional bottom out resistance I would suggest to increase Air Spring pressure and add additional low speed damping.

  8. #8
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    Thanks for all the great responses.

    kelstr -

    Do you need to add the oil to the air spring cartridge to help with bottoming, or do you get enough pressure in the outers to help with this?

  9. #9
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    Quote Originally Posted by forker
    Thanks for all the great responses.

    kelstr -

    Do you need to add the oil to the air spring cartridge to help with bottoming, or do you get enough pressure in the outers to help with this?
    you are better off just adding to the air spring cartrige to help with bottoming , ---

    if you still need more bottoming , ( which most guys will not ) ----you can add oil to the outters ----but specialized does not recomend this nor condon it ,

    i have some really big guys --225 lbs and over 6' 6" tall and they really pound the DH stuff hard , ( but they really like the enduro rather than their bigger heavier 8 & 10" bikes -----because they can pedal the enduro ----rather than shuttle all the time with their bigger bikes )

    and i have had to red-locktight the seals in and add oil to the outters ---but i am still in the testing stages and this should not be necessary .

    i play with it on mine to see what it will do -----

    most guys will be fine just adding to the air cartrides !!

  10. #10
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    Quote Originally Posted by kelstr
    i have some really big guys --225 lbs and over 6' 6" tall and they really pound the DH stuff hard , ( but they really like the enduro rather than their bigger heavier 8 & 10" bikes -----because they can pedal the enduro ----rather than shuttle all the time with their bigger bikes )
    Hey Kelstr, thanks for all the technical info provided on these forums. I also read the other info posted on the how to void the SL suspension bottoming out (the one you created).

    From your comments above regarding guys pounding the SL on DH, have they heavily modified their bicycles?

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