Anonymous
Anonymous asked in SportsCycling · 2 months ago

Is it possible for the rubber part of a bike tyre to be untrue?

I figured that my front bike tyre was slightly untrue and I tried trueing it but it didn't work. Now that I look at it, the rim dosen't look that bent, it looks like the actual rubber isn't aligned with the rim if you know what I mean but everything is fitted on correctly unless it is the rim? Would it be more likely to still be the rim?

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  • 2 months ago

    Possible but unlikely.

    As the others have said, most likely you have the tube pinched under the tire bead. You need to fix that because sooner or later a pinched tube will work its way out and you will suffer a blowout and a ruined tube.

    With the tire mounted, first inflate the tire to 5 psi or so. Now push the valve stem all the way into the rim and let the air pressure push it back out. With that done, go all the way around the rim on both sides, pushing the tire away from the rim and looking down inside. The tube at this point should be up inside the tire, not between the tire and rim. If you see the tube where it doesn't belong, play with the tire until you coax it back where it belongs. When you have inspected both sides all the way around and everything looks good, ONLY THEN should you fully inflate the tire. Even cheap tires should be pretty true if you've done all of that.

  • 2 months ago

    Possible but not likely. Much more likely that the bead isn't seated properly. Deflate the inner tube and try to go along the rim where the tire meets. Be sure it is even

  • 2 months ago

    Yes, it is very possible. I had a tire plump up in one area and split down the middle like a hot dog, but it was a lower-end tire.

    But if your problem is the bead is raised too much off the rim, then try taking the tire off the rim and rotate it to a another position on the rim. It should work.

  • David
    Lv 6
    2 months ago

    The most common scenario is that the reinforcement at the base of the valve stem gets trapped under the beads, which will cause a section of the bead to sit higher than intended. This usually results in an out-of-round tire that’s still mostly sideways true. The cure is to deflate, push stem in and reinflate.

    The 2nd most common scenario is an unusually loose fit between rim and tire which reduces the efficiency of the self-centering properties of the rim/tire interface. This will result in a more traditionally out-of-round tire.

    The cure is to deflate partially, pull/massage the tire into position, and reinflate.

    The least common cause is a defect in the ”carcass”, the load-carrying structure inside the rubber causing the tire to become deformed. Can happen either through a cut in the tire or a manufacturing defect.

    It’s rare, but it does happen.

    I’ve probably seen a grand total of 2-3 tires damaged this way. One of them visibly aged.

    • Land Rider Jerry
      Lv 6
      2 months agoReport

      Unfortunately the OP has admitted to prior trying to true the rim. Still good advice if the rim is actually true.

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  • 2 months ago

    The rim doesn't look that bent; meaning it is slightly bent??? You tried to true your rim??? So I'm assuming you have a truing stand and know how to use it??? Did you try to true the rim using the brake pad method??? Sorry but you can't do a precise truing using the brake pads. You need a truing stand for a precise truing. The best the brake pad method can do is give you an indication the rim isn't true. You probably did more damage than good.

    However let's say your rim is true; the next question is, did you put the tire on the rim correctly??? If you did, then is this some cheapo discount tire???

    Bottom line fixing the problem is beyond your skill level. Take the bike to a reputable bicycle shop for a diagnoses and possible repairs.

    Source(s): Motorized Bicycle Owner and Builder.
  • 2 months ago

    Possible but not probable. Tires go through a rigorous quality control check before being shipped out to distributors. It's more likely (as both previous answers mentioned) the bead of the tire isn't seating properly against the rim.

    Deflate the tire. Find a lubricant - soapy water usually does the trick. Apply that evenly around both sides of the tire bead. Re-inflate. If that doesn't work...got a bike shop close by? I say this over & over again here on Yahoo. Bike shops give FREE estimates. Won't cost you anything to roll the bike into a shop & ask.

  • 2 months ago

    I suppose it is possible that the tire may have some sort of defect in the manufacture of it but that is highly unlikely. if you turn the wheel slowly and watch it aligned with one of the brake pads or some other stationary point on the bike and it wavers as it rotates, it is because of the wheel is out, not the tire. The most certain way to confirm this is by removing the wheel from the frame, removing the tire and inner tube then reinstalling the wheel and rotating it once again. Truing a wheel is a tricky business and it may be that you aren't doing it correctly. I would suggest looking at several videos on the subject on Youtube to see if you can get your truing skills on point.

  • 2 months ago

    I guess the tyre bead isn't in place on the rim. You need to let the tyre down and re-fit it using some soapy water as a lubricant to help the bead slip into place. You might have to pump it up pretty high to get it to seat properly and then let it down to the right pressure.

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