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  1. #1
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    Question about" non-round" tires

    Does anyone have any experience with new tires that are out-of-round? I have trouble believing that reputable tire manufacturers, with decades of experience, would sell tires that have flat spots on them... like "whop, whop, whop, whop, whop, whop, whop, whop".

    I just rec'd a pair of light, hi pressure tires by Schwalbe, and they both have flat spots. Is this just me. Am I doing something wrong? Has anybody else ever had this experience? Schwalbe's been in the business forever, and you'd think "round" is a fundamental requirement for saleable tires!

  2. #2
    Galveston County Texas 10 Wheels's Avatar
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    It happens. Send them back.
    Last edited by 10 Wheels; 02-01-10 at 12:31 PM.
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  3. #3
    mosquito rancher adamrice's Avatar
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    Is it possible that the bead isn't properly seated all the way around? I've had that happen once or twice. Overinflating pops it out and gets it seated properly.

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    It's possible that the tires are out-of-round--but is pretty unlikely. The tires are manufactured by being blown up inside a female mold for hot-curing.

    Quote Originally Posted by adamrice View Post
    Is it possible that the bead isn't properly seated all the way around? I've had that happen once or twice. Overinflating pops it out and gets it seated properly.
    I would look at the sidewalls also. In particular, see that the molding seams (or generator strip, if they have one) on the tire are concentric with the rim.

    The tire may not be seating properly on the rims you have. They're supposed to fit correct--but with variations in rim edges and heights, may not. If that's true then you can just sell them and try another model or brand, or you can try shaving off a bit of the rim hook yourself with a sharp knife. On most bicycle tires the bead hook isn't really the "bead", it's just a lip of molded rubber and the bead is much smaller and located in the very edge of the tire. The bead hook can be trimmed down somewhat without harming any of the casing threads.
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  5. #5
    Senior Member Retro Grouch's Avatar
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    Quote Originally Posted by adamrice View Post
    Is it possible that the bead isn't properly seated all the way around? I've had that happen once or twice. Overinflating pops it out and gets it seated properly.
    That's what I think too. For some reason, once they've been seated initially it doesn't seem to be a problem after that. I sometimes spray windex onto the beads all the way around to help them slide into place.

  6. #6
    Bike addict, dreamer AdamDZ's Avatar
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    Yup, examine the sidewalls. That happened to me too. I pumped the tires above their rated pressure and they "popped" into place. There is also a tool for that.

    Adam

  7. #7
    Time for a change. stapfam's Avatar
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    Also had the tyre not seating properly but this has mostly been of poor quality rims that are a bit on the "Small" side and tyres that are a bit big.

    Now you want a problem- fit a very tight folding tyre on a "Big" rim. You would be happy whatever way that tyre gets on the rim.
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  8. #8
    mosquito rancher adamrice's Avatar
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    Quote Originally Posted by stapfam View Post
    Now you want a problem- fit a very tight folding tyre on a "Big" rim. You would be happy whatever way that tyre gets on the rim.
    Ugh, yes. I remember fighting with a Conti road tire on a cold day for something like half an hour. I think their tires must run towards the small end of the margin for error.

  9. #9
    Uber Goober StephenH's Avatar
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    On my Worksman cruiser, there's some clearance between the tire bead and rim, so if you don't intentionally center the tire on the rim, you can get it offcenter a little.

    I would tend to think an issue with the seating as described above is the culprit.

    Note that the whole tire could be manufactured with a considerable amount of ovaling, and it wouldn't matter, it would just round up to fit the rim anyway. What you're describing, if it was a manufacturing issue, would be a tire that was smaller in cross section in one spot in another. And it's more likely to be fitting on the rim two different ways in those places than to actually be two different sizes.
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  10. #10
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    The same general drift as a few of the posters already. I haven't experienced anything you could call a flat spot, but have had problems with bulges.

    There is a 'witness line' on most tires just above the rim that is a big help to see if it is seated evenly. Check that at about half inflated, and again when you are finished. If it is too high some place, let the air out and see if you can work the tube higher in the tire there. Or just fiddle around a bit. It usually doesn't take too much to get them to come out even.

    Good luck with that.
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  11. #11
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    Thanks for the advice. I smeared the sidwalls with soap and pumped up to 140psi, then watched as the sidewall slowly slid into place, ending with two 'ping's, one on each side.

  12. #12
    Bike ≠ Car ≠ Ped. BarracksSi's Avatar
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    Quote Originally Posted by bwilsonduncan View Post
    Thanks for the advice. I smeared the sidwalls with soap and pumped up to 140psi, then watched as the sidewall slowly slid into place, ending with two 'ping's, one on each side.
    Be careful when pumping them to force the bead into place. It worked this time, but you run the risk of blowing the tube as it forces itself though a gap between the tire bead and the rim hook.

    You should be able to get it settled correctly without pumping it over normal pressures. I use talcum powder on the tube to keep it from sticking to either the inside of the tire or the rim bed.

  13. #13
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    Quote Originally Posted by adamrice View Post
    Ugh, yes. I remember fighting with a Conti road tire on a cold day for something like half an hour. I think their tires must run towards the small end of the margin for error.
    I hear that. I run Conti GP4000s on my Fulcrums. I think they had an easier time at the Battle of the Bulge than I had getting those tires on. I invented new 4 letter words!

    Quote Originally Posted by BarracksSi View Post
    Be careful when pumping them to force the bead into place. It worked this time, but you run the risk of blowing the tube as it forces itself though a gap between the tire bead and the rim hook.

    You should be able to get it settled correctly without pumping it over normal pressures. I use talcum powder on the tube to keep it from sticking to either the inside of the tire or the rim bed.
    Been there done that. It was like a *** going off next to my head.....
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