Flat tire at high speed (non event)

Discussion in 'The Perfect Line and Other Riding Myths' started by Niterunnr, Oct 2, 2021.

  1. Niterunnr

    Niterunnr Adventurer

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    I recently learned a valuable lesson about flats. I punctured the rear tire on my Super Ténéré running Shinko E705 and found that with a safety bead, a flat tire (even at highway speed) was a non event. The hole was too large for one ”bacon strip”, but too small for two, so I ended up patching it multiple times to get home and eventually rode TEN MILES completely flat! By the very end one side had come off the bead but the other held the tire in place. Extremely squirmy, but manageable.
    I posted this on another site about the danger of running tubeless on wheels without a safety bead.
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  2. cyclopathic

    cyclopathic Long timer

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    I flatted on Mitas E-07 on sealed non-safety spoke rims and it never came off even riding 16mi on flat after double plug failed several times. Some tubeless ADV tires with stiff walls just don't wanna de-bead, no matter what.. safety rims overrated just saying
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  3. lnewqban

    lnewqban Ninjetter

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    If you had tools and one spare inner tube, you could install it and resume riding normally.
    If tools only, you could pack the interior with grass and make it back home even safer.
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  4. Niterunnr

    Niterunnr Adventurer

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    I agree that the ultimate setup is patch kit, pump, tools and spare tube. But for those who this setup isn’t realistic, a patch kit and pump get you out of most situations.

    You could be right about that, but in my case one side did come off, (see pic). Was the safety bead the reason one side held firm, or was it the design of the center channel vs bead rubber thickness?
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  5. mminob

    mminob MotoHolic

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    The safety bead size varies on different rims ? And some work well with different tires , stiff sidewall or soft sidewall ? High speed blow outs are rare thankfully.

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  6. norseXL

    norseXL Northman

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    Had the chain guard on my Sportster come loose and cut the rear tyre at 130 Km/h on the Autobahn,
    heard the sound like a pistol shot, wondered what it was, couldn't feel anything wrong until I reduced the speed to about 70, centripetal force and all that...
    ...then I was glad I had a wide handlebar and also that it did not happend a bit earlier doing 200 in the leftmost of four lanes.



    You can se the cut all around the the tyre...

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    Getting on the rescue vehicle

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  7. Niterunnr

    Niterunnr Adventurer

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    That’s really the point of this thread, that quite often you might hardly notice you have a flat. But since in my case one side did completely come off, how much of that holding power could be attributed to the safety bead? Some amount at least. I also have an Africa Twin that came with tubes that I’m not fond of for roadside repair; I was planning to seal them and go tubeless. I’m concerned as the front rim has no safety bead. I’m not sure how much added benefit there is on the front with the tube installed if it goes flat. Perhaps if Honda built it that way, the safety bead really isn’t needed up front and I can safely convert the wheel to tubeless?
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  8. davidji

    davidji bike curious

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    Honda "built it that way" for tubes. Don't count on plug & go puncture repair if you seal the rim to go tubeless.

    I sealed both my AT rims & went tubeless. Then I deflated the front at home and the bead seal broke. I knew it wouldn't be easy to reseat roadside (I didn't want to use ether & matches). so I reinstalled the tube in front. By the time I changed that front tire, the bead was held pretty firmly in place. Nowhere near as solidly as the rear though, and even that eventually gave up in your case.
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  9. Niterunnr

    Niterunnr Adventurer

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    Where you running stock rubber? Aren't some tires specifically designed for tubed applications? I think when they are, the bead is not as tight since it’s designed to be held by a tube and not critical to holding air.
    Anyone else had a tubeless front go flat? Maybe I’ll text mine at home and report back.
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  10. davidji

    davidji bike curious

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    This isn't about the bead holding air when inflated, this is about the bead remaining next to the rim & maintaining the seal when you get a flat. If you don't have bead retention grooves (raised center hump, I think you called it safety bead?), the bead seal with the rim is likely to break when you get a flat tire. If you can easily seat it at home with the stuff you carry on the bike, great. I can't. On my bike the rear has the grooves & the front doesn't, so my rear is sealed & tubeless, & my front still has a tube.

    Tires come in in tubeless (with a TL sidewall marking) & tube type (with a TT sidewall marking, like the OEM rubber on my AT). Very few people will try to run a TT tire tubeless. I won't. Most tire available for our bikes are TL.
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  11. foxtrapper

    foxtrapper Long timer

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    Some time ago I saw an interesting picture of a an old racing MG cornering hard on its tubed tire and non-retention rim. The tire bead was pulled off the rim at the contact point on the roadway. The tube was holding the air pressure. Without it, things would have been catastrophic.

    Yes, I know that motorcycles don’t side load a tire the way a car does.

    Some sidewalls are quite stiff, some not. Some beads stick strongly to the rim, some not.
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  12. farqhuar

    farqhuar Human guinea pig

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    Flats need not be a problem. 8 years ago I rode 220 miles with a flat front tyre (D606) across the Australian desert (all sand and up and down close to a thousand dunes) on my KLR.
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  13. scottrnelson

    scottrnelson Mr. Dual Sport Rider

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    Try getting a flat front tire at speed and let us know how that goes...

    I hit a rock of some sort on a KTM 990 Adv while heading right into the sun on a twisty downhill mountain road. Two turns later the front was flat and I couldn't steer. Turn the bars and it would go a different direction than where the front wheel was pointed. I eventually figured it out and got it stopped at the far left edge of the road. Good thing there was no oncoming traffic or I probably would have had to "lay 'er down".

    That's the closest I've come to crashing on the street in 18 years of crash free riding. I don't ever want that experience again. I've had quite a few flat rear tires while riding and they generally don't scare me unless I'm trying to lean over in a turn.
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  14. Gone in 60

    Gone in 60 Been here awhile

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    I've been lucky to have had only one flat in my years of riding, and the situation was even luckier. In regards to not knowing you've got a flat, that was my situation. Riding on old, stiff tubless tires on my current CB1100, I picked up a nail somewhere on my commute home, but didn't notice until I reduced my speed to exit the freeway, from about 70 to exit speed. As such, I don't know where along the ride the tire started going low, but once I felt the rear getting squiggly on the deceleration, I quickly figured it out.

    There's a gas station at the end of my off ramp, so I was able to pull in, give a quick look to spot the nail and put some air in the tire for the 1.2 mile ride to my garage. The nail head was quite worn, so it had been in there for a good portion of my ride, and I was almost flat by the time I got home, so the air loss was pretty rapid.

    The lucky part? My new tires had just arrived, and my project that night was to pull the wheels and swap them over.
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  15. dixda

    dixda Been here awhile Supporter

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    That reminds me of the first Italian Job movie when it showed the radial tires slopping off the rims on the hard turns.
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