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  1. #1
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    first tubeless conversion and troubleshooting

    Hi all,

    Last night I finally decided it was more then time that I started making my tires tubeless. I have a pair of Hope 29" Enduro wheels. I was using 25mm DT Swiss rim tape and tubeless valves. Stans fluid.
    So I started with the front, which went fine. It held air after a while and this morning, it was still holding air fine. Succes!
    The rear wheel was next. I seemed to be doing a better job with the rim tape, It held air fine but this morning it was all flat. Soapy water revealed that it's leaking air by the second and third spoke away from the valve. What could be causing this? And if air can get to those 2 spokes, why does it not seem to leak air through all the other spokes holes?
    What more can I do to stop this leaking and what could cause it and more so, why does the sealant not seem to 'fix it?
    Anyone any idea? I thought I did a good job taping the rim so I'm a bit lost.

    Thank you.

  2. #2
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    Sounds like you are close...if the leak is that small the sealant should do it's thing if you give it some time. Take wheel off the bike, press it up to 40-50 psi and really bounce it around to get the sealant where it needs to go.

    If that does not work...
    1. Did you put in 2-4oz of sealant? If not, put more in.
    2. Follow Stans directions and shake well, hold finger over nozzle, turn bottle upside-down, to let larger sealing particles settle to nozzle, then let sealant into tire. Use same principle if adding sealant through valve with tubing.

    I've had a small leak or two during install (usually valve stem area) and every time it eventually sealed by sloshing things around and giving it a chance to seal.
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  3. #3
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    Well, first up, as Sturge said, sounds like sealant should solve your problem, maybe, but I always like to start with a setup that doesn't "need" sealant except to seal punctures. So for me, first I'd pull the tyre and check the tape, if it looks good, no edges looking like they're peeling up, then install the tyre with a tube and let sit overnight at 35 PSI to help seat the tape - I always do this when I first setup a tubeless setup, makes a big difference in getting the tape seated and sealed good.

    Try re-installing the tyre once you've let the setup sit overnight with a tube, if it still won't hold air (install the valve with some sealant around the rubber part) make sure to press down on the valve with your thumb hard as you tighten the lock nut, then check the tape for possible little slices/holes (had this happen when laying down tape in a rim with extremely deep cavity).

    If all that fails, you did actually start out with too narrow tape, you should be using tape 4-5mm wider than the inner width of the rim you're taping to account for the dip in the channel, so get some 27-30mm wide tape and re-tape - you want the tape over the bead lip and up against the rim wall so that it's a seal between the tyre and tape and nothing to do with the rim, as some rims that aren't always perfectly sealed at the joint.
    One day your life will flash before your eyes, will it be worth watching??

  4. #4
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    Thank you both for the replies.
    It sounds like I'm not doing too much wrong. I just have to be more patient and shake the fluid around some more.

    I'd still like to know if there is a reason why air only escapes out of 2 spoke holes and not all of them. As far as I see, they are all just connected with a 'channel' in the rim, no?

    Anyway. I'll get back on it when I get home. Just hope I can avoid taking the tire back off the rim.

  5. #5
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    Could be the tape nearest those spokes.

    Air will escape the path of least resistance. Usually it will show a leak around the valve because it's the largest hole. Air will get under the tape and find way to the largest void/least resistance.

    I'd agree that if it held air a while that you should get a seal soon with the sealant. If air escapes withing an hour lets say, then there is an issue that sealant may not repair.

    Good luck.

  6. #6
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    Cause those nipples are not sealing against the rim as well as the others. Nipples press hard against the inside of the rim and will seal to a degree, some better than others. This is why leaks into the rim usually show up around the valve stem, which doesn't seal to any real degree against the outer wall of the rim. Some stem nuts have an o-ring, which may, or more likely not do anything in this respect.
    Do the math.

  7. #7
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    I am inclined to think it's the tape job or the tape/valve interface inside the rim allowing some air through. That would make it unlikely that sealant would stop it. Just check it again and see how it looks.

  8. #8
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    Ok, a week later...
    I managed to get the tires to hold by adding some more sealant and shaking the tires around more. Thank you all for your input.
    I've since done a 500km bikepacking race on this bike and no problems whatsoever.
    I'm convinced... only 10 years too late

  9. #9
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    Its the tape. Happened to me. I had to retape it. Somehow the air found a path under the tape via a crease and escaped through the nipple hole.

    Ive had tires that seeped very tiny stream of air bubbles from many parts of the maxxis exo sidewall which results in a slow leak and will render a tire almost flat after 2 days. I dont think there is enough air pressure and small particles to push sealant to fill these tiny holes. Is there any fix to this?

    Sent from my SM-G973U using Tapatalk

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