Rear tyre squirming

JBA
JBA Posts: 2,852
edited September 2016 in MTB general
I have just converted to tubeless using Schwalbe Nobby Nic tyres on Giant SXC-2 rims.

First ride in anger last night and the rear tyre feels like it is squirming or rolling sideways when cornering. The tyre is a 2.25 Evo Snakeskin Pacestar. The feeling was very disconcerting and didn't inspire confidence. I am concerned the tyre may roll off the rim.
I'm running about 38psi in the tyre and I weigh just over 100kg.

Is the squirming down to tyre pressure, narrow rim, soft tyre sidewall or something else?
Any advice gratefully received.
“Life has been unfaithful
And it all promised so so much”

Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Toughtroad SLR 1 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009

Comments

  • lostboysaint
    lostboysaint Posts: 4,250
    I'm a similar weight and have no issues with either of my tubeless set ups with 35-40 psi in. I do have much wider rims than those, however, so I don't have the "balloon" issues of a very round profile tyre on a narrow rim - so it may well be that.

    Tubeless does feel different, it does feel "soft" but I've never felt that the tyre would roll off the rim. Just that it's providing the sort of grip and feel that a lower pressure tyre should!
    Trail fun - Transition Bandit
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  • JBA
    JBA Posts: 2,852
    Yeah, the rims are only 19mm wide.
    I'll up the pressure a bit and see if that helps.
    If not, I shall have to try and get a new pair of wheels approved by SWMBO. :shock:
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Toughtroad SLR 1 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • The Rookie
    The Rookie Posts: 27,812
    Shouldn't feel any different to with a tube in!

    QR tight?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • cooldad
    cooldad Posts: 32,599
    Especially at those pressures, which are pretty high. Sure it's not bouncing or skipping off bumps?
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  • JBA
    JBA Posts: 2,852
    Checked the tyre pressures today with a new pump and they were no where near what my other pump said they were!
    Rear was only at about 25psi. Upped it to 38psi using the new pump and the squirming has disappeared.
    That made for a much better ride at Cwmcarn this afternoon. :D

    Using the tried and tested squeeze with a thumb method the rear tyre didn't feel particularly soft before I checked it today. Maybe my thumbs are out of calibration as well?

    Anyhow, old pump is now in the bin and normal enjoyment has resumed.
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Toughtroad SLR 1 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009

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