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  1. #1
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    Check the presta valve on the tire side of the rim. The rim is sealed all the way around the rim but has a hole for the valve, so air is getting around the valve seal and going into the "box" section of the rim. How old are the valve stems? Running Stan's sealant fixes that problem most of the time.

    Colin
    Auburn Bike Works

  2. #2
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    Crossmax sl ust-loosing air via spokes?

    When i poured some water on a ust tire repair to check it was sealed i noticed there were small water bubbles where the spoke nipples screws into the rim....

    I took the worst spoke out ,and put a drop of tire glue onto the tread and screwed it back in which solved the air leak....

    There are about 5 spokes that need this doing but what i dont understand is how is the air from the tire leaking out via tha rim and spoke nipples?.....
    2002 M Cannondale Jekyll Goodboy 30th Aniversery...#017-300....

  3. #3
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    Are You running sealant?

  4. #4
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    Iv just put a brand new Mavic ust valve on and and im still getting air leaks from some nippless....the front wheel is fine though....

    The valve is propperly seated in the rim and screwed on tight with a rubber "o" ring seal under the screw down colar so i cant see how air is escaping....il see how it goes overnight but might put some rubber tire glue where the valve seats inside of the rim then screw it up tight again....
    Last edited by qwackers; 03-27-2011 at 09:36 AM.
    2002 M Cannondale Jekyll Goodboy 30th Aniversery...#017-300....

  5. #5
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    Not running any sealant....never have in the past 9 years of having ust so i cant see why its just started now....
    2002 M Cannondale Jekyll Goodboy 30th Aniversery...#017-300....

  6. #6
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    If it's leaking air through the spokes it's simply because the valve is not seated properly on the inside of the rim.
    That causes air to seep through the hollow part of the rim and then through your spoke holes.
    Had the same issue on my 819's and fixed it by using STAN's valve stems.
    "Common sense isn't always that common!"
    Custom Prophet and Custom "Leftified" Delta V

  7. #7
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    air

    its a known problem on longer used ust rims (the price of low weight maybe)
    check for small cracks around de valvehole or @ the weld

    if the wheel is 9 years old its probably finished

    with sealant you can get some more miles out of it but if my rim starts to crack i think i would replace it

  8. #8
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    check for longitudinal crack near valve hole.
    it looks like damaged paintjob.

    if there is no crack, new ust valve and latex milk will fix leaking..

  9. #9
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    Ive checked the rims and theres no cracks but put some rubber glue around the valve hole in the rim and where the rubber block sits in the rim and that helped alot....

    There new mavic valves as well....i put 60psi in the tires every time a go out but if i dont go out for a few days the tire has dropped to about 30....which i think is normal for ust....

    But this was going flat overnight so it must of been the valves....thanks everyone....
    2002 M Cannondale Jekyll Goodboy 30th Aniversery...#017-300....

  10. #10
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    60psi is way high for a mtb tire. The point of ust is to run less than 35psi without pinch flats.

  11. #11
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    Hutchinson Pythons 26x2.00....it can run 30-60 psi so i run 60 as i ride dry hard pac....canal paths and trails....so the Pythons tread-spec and psi are perfect for me....
    2002 M Cannondale Jekyll Goodboy 30th Aniversery...#017-300....

  12. #12
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    Even on hardpack you would benefit from lowering the pressure.

    Be it for comfort, losing 15 or more won't make a big difference, but when getting the unpaved section gains are there.
    Pressure is good on track, on trails is a no go.

    Since I'm running tubeless on my road bike got rid of 25 psi, the only difference is a lot more comfort.
    Low pressure seems a no go but there are numerous tests around proving otherwise.

  13. #13
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    Quote Originally Posted by qwackers
    Hutchinson Pythons 26x2.00....it can run 30-60 psi so i run 60 as i ride dry hard pac....canal paths and trails....so the Pythons tread-spec and psi are perfect for me....
    I used to run pythons on my f3000, they ride much better below 40psi. Even on hard pack.

  14. #14
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    I also had air leaking from the spokes, and it was exactly as others have described, it leaks from the valve hole to the inner hollow core. I put some silicon on the valve and stuck it back in and it's been air tight ever since, better than new. These are 819's from 2002, so age is no issue.
    Attached Thumbnails Attached Thumbnails Crossmax sl ust-loosing air via spokes?-image001.jpg  


  15. #15
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    Mavic recommends to replace the valves yearly... probably to avoid this exact issue.

  16. #16
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    Most probably know this, but there is no need to buy Mavic valves.

    Simply cut the valve out of an old tube. Use a piece of the old tube to create a washer that will go between the stem and rim (the rubber on the stem alone is not always enough to fully seal).

    I've only been using these ghetto tubeless stems for a few months, so I can't comment on the long term durability, but all of the ones I've made have sealed easily and been trouble-free (as opposed to the lightweight, but useless stems that ship with American Classic wheels). One of them even replaced a Mavic stem on Mavic tubeless wheels.

    -Pete
    I can barely get my mouth around it.

  17. #17
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    If I have a $900 set of wheels I don't have a problem paying about $20 for some new valves every now and then...

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