unbalanced wheel following inner change?

GordonFreeman
GordonFreeman Posts: 120
edited April 2012 in Workshop
Not sure what could cause this but I replaced the inner tube as I accidentally broke off the presta valve.
On riding it today, it felt bumpy on the front wheel.
I just took it off, took the outer off, reseated the inner and put it back on but still the same thing.
Any ideas what this could be?
It doesn't look like the rim is moving so it can't be fixed with spoke adjustments I don't think.

http://www.youtube.com/watch?v=FKD99tsVAeo

Comments

  • desweller
    desweller Posts: 5,175
    The tyre bead's not seated in the rim. Try dusting the inside of the tyre with some talcum powder and partially inflating the tube before fitting it.
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  • DesWeller wrote:
    The tyre bead's not seated in the rim. Try dusting the inside of the tyre with some talcum powder and partially inflating the tube before fitting it.

    Tyre bead?
  • desweller
    desweller Posts: 5,175
    tires_cutaway_bg_405_m.gif
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  • rolf_f
    rolf_f Posts: 16,015
    The lip on the inside edge of the tyre. It needs to be seated properly. When you put the tyre on, before you pump it up, you need to push the edges of the tyre towards the hub of the wheel to make sure the beads are seated properly. In your case, part of the tyre isn't seated properly. Roll the bike slowly along and feel for when you get the bump - then have a close look at the tyre at that point. You should see that if there are any mouldings on the tyre that follow the circumference - at that point they will bulge away from the wheel. Note you'll need to check both sides.
    Faster than a tent.......
  • Rolf F wrote:
    The lip on the inside edge of the tyre. It needs to be seated properly. When you put the tyre on, before you pump it up, you need to push the edges of the tyre towards the hub of the wheel to make sure the beads are seated properly. In your case, part of the tyre isn't seated properly. Roll the bike slowly along and feel for when you get the bump - then have a close look at the tyre at that point. You should see that if there are any mouldings on the tyre that follow the circumference - at that point they will bulge away from the wheel. Note you'll need to check both sides.

    It looked my like it was a divot rather than a bump, could that be possible? ie an area that wasn't inflated enough?

    The area where it occurs doesn't bulge away, it looks like it sinks lower and no matter what I do, I can't get it to sit right.

    Tyre says 15psi, what psi can I got to to try to get it to sit correctly?
  • Twostage
    Twostage Posts: 987
    The rim doesn't seem to be moving so that's ok. My guess (although I can't make it out in the video) is that the tyre is not seated properly where the valve is. Deflate the tyre almost completely then push the valve in towards the tyre whilst pushing the tyre against it and the tyre should pop in 'under' the valve. If that is the problem anyway.
    By the way the inflation pressure should be at least 90 psi.
  • Twostage wrote:
    The rim doesn't seem to be moving so that's ok. My guess (although I can't make it out in the video) is that the tyre is not seated properly where the valve is. Deflate the tyre almost completely then push the valve in towards the tyre whilst pushing the tyre against it and the tyre should pop in 'under' the valve. If that is the problem anyway.
    By the way the inflation pressure should be at least 90 psi.

    Well, I inflated as much as I could with my hand pump, maybe I should head to the cycle chop and inflate it properly using their free tools. It's a "Specialized" 700 x 20/28c. Maybe that's the problem, previous inner was something else 700 x 24/28 something like that. I'm pretty sure it's the right one though.
  • desweller
    desweller Posts: 5,175
    The bead sometimes 'sticks'. Hence talcum powder helps it to slide into position on the hook in the rim.

    Have you tried deflating it, removing and refitting with the tube partially inflated yet?
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