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  1. #1
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    tubeless + 3' drop = loud farting noise + endo onto head...

    Well, just a few days ago I prepped my Alexrims xd Lite & put a brand new specialized purgatory control tire on it (front only, I was trying one at a time). I used the 2oz of Stan's and lots of soapy water to help the bead seat.

    I rode it around the street a little bit, and it held air pretty well.

    Today, maybe 3 days later, i went riding and rode off of a ~3-4 foot culvert pipe (square) into a grassy area.

    I landed both wheels at the same time, but immediately heard a loud farting noise and went over the handlebars. I bounced a little on the top of my head (thank you, helmet) and rolled out of it. The bike flew off my feet and went a few yards further.

    The front tire was completely off the bead, and the front wheel is kinda bent and wobbly now...

    I was able to get the bead seated again, using the little CO2 inflator, and rode back home.

    My first experience with tubeless is not all that fantastic; although it was probably my fault for using a rim not specifically designed for tubeless use. I think I'll be going back to using tubes.

    Now I need to figure out how to get my rim straightened again. I guess there's a little wrench I can buy.

  2. #2
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    how many PSI were you running on that front tire? Getting a tubeless compatible rim helps, but I've heard and seen people with tubeless conversions that loved them with no issues.

  3. #3
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    Sounds like the combination of too low of tire pressure, rimstrike, and non tubeless ready wheelset. You can try adding more PSI to your tires to help it from rim-striking/burping. If your budget allows get a tubeless ready wheelset such as Stans notubes Crest or Flow.

    What PSI did you have upfront by the way, also what is your wieght?

  4. #4
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    I don't know if that was a tubeless issue.

    If you hit as hard as it sounds like you did, you likely would have pinched a tube.

    My brother just crashed hard last weekend, and blew the tire off the bead of his rim as well. Easton Haven 26", which I understand are tubeless ready rims.
    He hit so hard that the front end twisted, and again, the tire blew off.

    This sounds like a simple crash, not a failure of the tubeless setup. I'm thinking something on the impact itself took the tire off the rim, which again, if it would have been tubed, probably would have resulted in a pinched tube and possibly also a blown off the rim tire.

  5. #5
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    I weigh like 165 or so. The air pressure was just over 30psi. I've done the jump many times with a different (tubed) tire without any problems or wheel bending...

  6. #6
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    maybe there was a rock or something in the grass too, it was several inches high.

  7. #7
    Bandit 29 FTW!!!
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    What kind of bike? Was it a full-squish?
    Let's make like a Bike and get the Huck outta here...

  8. #8
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    I weigh about 100 lbs more than you do and have used up three 29" Purgatory front tires, all tubeless. I've never run more than 30 psi and have yet to burp one. Something doesn't quite add up unless that Alex rim is unsuitable tubeless use. It's kind of the wild, wild west out there for doing ghetto-tubeless conversions, but I have had very good luck with Specialized 2-Bliss tires.

    An 18mm inner width rim is getting toward the narrow end of the rim width range, and would be more apt to let the tire 'roll' if subjected to side load, but I still have a hard time imagining that happening if the tire was truly at 30 psi. My best guess would be that the tire had lost some air before actually burping. If it actually did have 30 psi, you might need another layer or more of tape on the bead shelf.

    Of course, it would be more confidence inspiring to have a known good tubeless compatible rim to couple with a known good tubeless tire like the Purgatory. My suggestion would be to use either a rim from Stans (Arch EX or Flow EX) or a WTB Frequency (i23 or i25). there are more that work well enough, but the ones I mentioned are generally no-brainers to set up tubeless.

    Since the rims you have are somewhat of an unknown quantity regarding tubeless use, it might be a good idea to go back to tubes until you either get more data and information for using the Alex rims tubeless, or get some rims designed for tubeless use.

    FWIW, I have been cleaned off of my bike by a rock hiding in the grass myself. I never saw it coming and was all of a sudden sent flying through the air superman style. It happens. Be safe out there.

  9. #9
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    tubeless + 3' drop = loud farting noise + endo onto head...

    Quote Originally Posted by L8APXR View Post
    Well, just a few days ago I prepped my Alexrims xd Lite & put a brand new specialized purgatory control tire on it (front only, I was trying one at a time). I used the 2oz of Stan's and lots of soapy water to help the bead seat.

    I rode it around the street a little bit, and it held air pretty well.

    Today, maybe 3 days later, i went riding and rode off of a ~3-4 foot culvert pipe (square) into a grassy area.

    I landed both wheels at the same time, but immediately heard a loud farting noise and went over the handlebars. I bounced a little on the top of my head (thank you, helmet) and rolled out of it. The bike flew off my feet and went a few yards further.

    The front tire was completely off the bead, and the front wheel is kinda bent and wobbly now...

    I was able to get the bead seated again, using the little CO2 inflator, and rode back home.

    My first experience with tubeless is not all that fantastic; although it was probably my fault for using a rim not specifically designed for tubeless use. I think I'll be going back to using tubes.

    Now I need to figure out how to get my rim straightened again. I guess there's a little wrench I can buy.
    Standard tires, Standard rims, no tubes, sealant, does not equal tubeless.
    Might work.
    Might not.
    In your case, not.
    mtbtires.com
    The trouble with common sense is it is no longer common

  10. #10
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    I thought the technical term was "burping?"
    But "farting" is wayyyy funnier.

  11. #11
    Yes, that's fonetic
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    Quote Originally Posted by L8APXR View Post
    I weigh like 165 or so. The air pressure was just over 30psi. I've done the jump many times with a different (tubed) tire without any problems or wheel bending...
    You said this was 3 days after you set it up. Did you check the pressure on the day it failed or was the 30lbs the initial pressure?

  12. #12
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    Quote Originally Posted by shiggy View Post
    Standard tires, Standard rims, no tubes, sealant, does not equal tubeless.
    Might work.
    Might not.
    In your case, not.
    This

    It obviously was an issue with your rim/tire combination. They were not able to withstand what you are trying to do with them.

    Even if you have had a pinch flat with a tube, it would not have been instant failure causing you to crash and bend a rim.

    Either buy a proper tubeless set up or run tubes.
    I have tubes in one bike and tubeless in another. I am happy with both set ups.
    Just stick it in granny and start grinding.

  13. #13
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    just as a follow up:

    I took the stans strip out of the tire and threw it in the trash. I put a tube back in and trued up my wheel as best I could. some spokes really tight now, and some rather loose.

    I went back to the spot and rolled off it 15x or so, and no problem whatsoever. was a little nervous the first couple times, I have to admit, and was going quite a bit slower.

    My son took a really crappy grainy photo of me doing it. For some reason it looks a lot higher over the handlebars than it actually does from the side, lol.

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  14. #14
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    Re: tubeless + 3' drop = loud farting noise + endo onto head...

    Quote Originally Posted by L8APXR View Post
    .

    I went back to the spot and rolled off it 15x or so,.

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    You rolled of that ledge? That we need a picture of ha ha.

    Anyway like others have said, your ghetto set up is a crap shoot. Often works OK. Sometimes not.

  15. #15
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    You sure the loud fart was from the bike? I usually just blame the dog.

    The two times I have burped a tire (both times it was on a full UST setup) it was more of a pop than a fart sound.
    15mm is a second-best solution to a problem that was already solved.

  16. #16
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    Some rims and tires don't work tubeless ,Stan's has a list of tires not to set up tubeless.

  17. #17
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    Quote Originally Posted by L8APXR View Post
    just as a follow up:

    ...some spokes really tight now, and some rather loose.

    I went back to the spot and rolled off it 15x or so, and no problem whatsoever. was a little nervous the first couple times, I have to admit, and was going quite a bit slower.


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    Video next, please. From below the drop rather than looking down at it. TIA
    Sometimes, you need to go fast enough that the trail is a blur to find clarity. -- Wild Bill

  18. #18
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    Quote Originally Posted by Glide the Clyde View Post
    Video next, please. From below the drop rather than looking down at it. TIA
    lol, will it look different from below?

    he'd have to sit in the grass or something while I fly over him? I don't think he'll go for it... (I dont think I'd want him to either)

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