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  1. #1
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    Tubeless feels squirmy ?

    Just converted a Pecenti Neo-Moto 650b on a Stans Flow rim. Set @ 35 psi same as tubed for a starting point. Within 50 yards I had that flat / low on air sensation. Checked the tire right @ 35psi. Finished the ride and the whole time the tire just felt under inflated. Do I need to get use to the feeling or add more air ? Secondly I noticed some dirt streaks, in a couple spots, from the bead on the sidewall of the tire did I burp some sealant ? Air pressure was @ 32psi when I got home. Thanks.

  2. #2
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    It could be that your rims are too narrow (inner width).

  3. #3
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    Quote Originally Posted by schristie11 View Post
    It could be that your rims are too narrow (inner width).
    Stans Flow has a 22.6mm inner width = not narrow on any account.

  4. #4
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    Just converted a Pecenti Neo-Moto 650b on a Stans Flow rim
    Before the conversion the tube would help stiffen the sidewall. Instead of squirmy some would say it's more supple.
    CRAP... I'm in the wrong gear

  5. #5
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    Maybe the tire sidewall is too pliable, consider a different sidewall tire perhaps?

  6. #6
    Save Jesus
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    A (butyl) tube in a tire acts as a damper and eliminates small vibrations, which gives the tire a dead, stiff feel. A tubeless tire feels more "lively", and thus makes you think there is "squirming" going on. An inner tube does not "support" the sidewalls because it is a soft, flexible piece of rubber that pretty much has no structural properties on its own. (Even when inflated) A tire gets its mechanical properties via turgor pressure because the tire casing is the thing that does not stretch. My guess is that if you did mechanical testing of a tire, the setup with the inner tube will actually be softer at the same psi because a few psi is used up inflating the tube to the same diameter as the tire.

  7. #7
    is turning a big gear
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    Quote Originally Posted by keen View Post
    Just converted a Pecenti Neo-Moto 650b on a Stans Flow rim. Set @ 35 psi same as tubed for a starting point. Within 50 yards I had that flat / low on air sensation. Checked the tire right @ 35psi. Finished the ride and the whole time the tire just felt under inflated. Do I need to get use to the feeling or add more air ? Secondly I noticed some dirt streaks, in a couple spots, from the bead on the sidewall of the tire did I burp some sealant ? Air pressure was @ 32psi when I got home. Thanks.
    If you lost 3 psi then it sounds like you could have either burped or your tire has not fully sealed up. If it keeps happening, you might want to re-evaluate the tire choice or try adding another layer of tape.
    Get it unlocked.

  8. #8
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by keen View Post
    Just converted a Pecenti Neo-Moto 650b on a Stans Flow rim. Set @ 35 psi same as tubed for a starting point. Within 50 yards I had that flat / low on air sensation. Checked the tire right @ 35psi. Finished the ride and the whole time the tire just felt under inflated. Do I need to get use to the feeling or add more air ? Secondly I noticed some dirt streaks, in a couple spots, from the bead on the sidewall of the tire did I burp some sealant ? Air pressure was @ 32psi when I got home. Thanks.
    I need more pressure in a tire without a tube than the same tire with a tube to prevent squirm.
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  9. #9
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    What's your weight and what pressure did you run with a tube?

  10. #10
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    I weigh close to 200lb w/ gear. The Pacenti Neo-moto is commonly run tubeless - there are only a hand full of 650b tires anyways. I always felt the Neo-moto was a good candidate for tubeless because the tire durometer felt stiff. I have read probably 100 tubeless tire posts and I always see low (20-30 psi) tire pressures being run.

  11. #11
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by keen View Post
    I weigh close to 200lb w/ gear. The Pacenti Neo-moto is commonly run tubeless - there are only a hand full of 650b tires anyways. I always felt the Neo-moto was a good candidate for tubeless because the tire durometer felt stiff. I have read probably 100 tubeless tire posts and I always see low (20-30 psi) tire pressures being run.
    Durometer refers only to the hardness of the rubber compound. Has little to do with the stiffness of the casing or overall stiffness of the tire.
    Last edited by shiggy; 08-26-2012 at 04:07 PM.
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  12. #12
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    Quote Originally Posted by keen View Post
    I weigh close to 200lb w/ gear. The Pacenti Neo-moto is commonly run tubeless - there are only a hand full of 650b tires anyways. I always felt the Neo-moto was a good candidate for tubeless because the tire durometer felt stiff. I have read probably 100 tubeless tire posts and I always see low (20-30 psi) tire pressures being run.
    20-30 psi but probably not at your weight with those tires.

    Increase the pressure until you don't feel too much "squirm"

    When I first started playing with low pressure I also tried 20ish psi like a lot of people recommended. Great grip in a straight line but would wash out or fold on its self when I try to turn.

    My tires were not meant to run tubeless so I had to increase the pressure due to the soft sidewalls.

    Play with the pressure an use what works

  13. #13
    Trail Tire TV on blogger
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    Quote Originally Posted by Jay Uno View Post
    20-30 psi but probably not at your weight with those tires.

    Increase the pressure until you don't feel too much "squirm"

    When I first started playing with low pressure I also tried 20ish psi like a lot of people recommended. Great grip in a straight line but would wash out or fold on its self when I try to turn.

    My tires were not meant to run tubeless so I had to increase the pressure due to the soft sidewalls.

    Play with the pressure an use what works
    ya.. not running those tires/size/setup... but being in the same weight area... I'd say run around 30 front and 35 rear...

    also big question no one asked... what size tire? when I ran a 2.4 or 2.5 on skinny rims they would squirrel out bad .. 2.2 not as much . Went to P35's and blunts, with the wider rim helped get rid of it a little bit.
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

  14. #14
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    Quote Originally Posted by shiggy View Post
    I need more pressure in a tire without a tube than the same tire with a tube to prevent squirm.
    What he said.
    Try running te same tire with and without a tube and see for yourself

  15. #15
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    It is prolly something you will get used to. If not, add psi.

    Different tires respond differently to tubeless vs tuned use.

    If you do slow technical riding, the squirm will not be as noticeable as when you do fast flowy riding.

    Adjust pressure to taste.
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