Tyre not fitting well

angusabroad
angusabroad Posts: 38
edited August 2022 in MTB workshop & tech
Hi,
Got this Shwalbe Nobby nic on my bontrager race wheels 26 inch . But I can't seem to stop one part of the tyre seating too deeply in the rim whilst the opposite side is 2 mm higher. This causes a bobbing motion when riding. I've tried many things but still no luck. Any tips you can suggest. Ps tyre is good and rim is straight. Thanks

Comments

  • steve_sordy
    steve_sordy Posts: 2,452
    edited August 2022
    There is usually a line that runs around the tyre that will lay parallel to the rim. That line will act as a guide to seating the tyre on the rim when first installing.

    Have you tried inflating to 60psi? The tyre should pop into place with a loud "bang"!" In fact there may be several bangs. This always happens when I'm installing a tubeless tyre. It is such a long time since I used a tube that I can't remember ever having that problem that needed fixing. Check after every bang to see if the lines are parallel, if so, stop inflating! :)

    If that doesn't work, try this. I know it works because I occasionally have to do this even when banging the tyre into to place.

    To move the tyre to get the line parallel, reduce the pressure a lot, 5 -10psi ought to do it. That is enough to keep the tyre inflated, but not enough to prevent you moving the tyre. Remove the wheel from the bike.

    Once you have reduced the tyre pressure, hold the wheel in both hands with one hand either side of the part of the line you want to move away from the rim. Holding the tyre firmly, wave the wheel up and down. The idea is to use the weight of the wheel to move the tyre on the rim. It will take a few goes to get the hang of it. Work your way around the tyre, looking at both sides until the line on the tyre is parallel to the rim. If the tyre won't move then reduce pressure some more until it does move!

    Once the lines are parallel, inflate the tyre properly and if it still wobbles then the tyre might be faulty, or you've got a dodgy rim.
  • The Rookie
    The Rookie Posts: 27,812
    Sounds like you have a hooked tubeless rim and tubeless compatible tyre, they often need a little soapy solution round the bead for them to 'pop' into place.
    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.