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Rear tire constantly flat!

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Rear tire constantly flat!

Old 08-01-19, 05:59 PM
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Alphonsus
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Rear tire constantly flat!

I only use my bike in the summer(2 months)in order to get to my summer job. Have had my bike for 2 years now. Last year had my rear tire get pop twice, one was a pretty big gash, and forget what other look like. The past 2x I hit a curb trying to jump it(my tires weren't hard rock). Today I got a flat just riding it, didnt do anything fancy.

My question is first should my mtb tires be hard rock, usually I leave it so there is some indention when I press on the tire. However had my bike tuned this Tuesday, and the shop had pumped my tire rock hard. 2nd question, is there a problem with the rim's or tire or something and not the way I ride? I'll post a pic of what today's flat looks like
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Old 08-01-19, 06:43 PM
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Well, do you pump your tires up before riding? Its probably not necessary every day but if you're getting flats and jumping curbs and what not, you should probably go to the max inflation listed on the sidewall of the tire. It sounds like your curb jumping excursion was what we like to call a pinch flat.

Next time you get a flat, take the tube out and figure out where it flatted and why so you can prevent the cause rather than just patching it up and hoping for the best.
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Old 08-01-19, 07:07 PM
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Get a pump and a pressure gauge and pump them up to something in the recommended tire pressure range. When you get a feeling of what works and what doesn't, you can play around and see what works best.
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Old 08-01-19, 07:12 PM
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Alphonsus
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Originally Posted by TrojanHorse
Well, do you pump your tires up before riding? Its probably not necessary every day but if you're getting flats and jumping curbs and what not, you should probably go to the max inflation listed on the sidewall of the tire. It sounds like your curb jumping excursion was what we like to call a pinch flat.

Next time you get a flat, take the tube out and figure out where it flatted and why so you can prevent the cause rather than just patching it up and hoping for the best.
Usually the holes is near the valve, my pump that I use doesnt correctly say the air pressure so probably gonna need to get a small one on Amazon that correctly tells me the pressure. Problem is I dont know the "why"
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Old 08-01-19, 07:31 PM
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A large gash in the tube that's not accompanied by a gash in the tire, indicates a pinched tube, where the tube is between the rim and the tire bead. When inflated, the tube eventually pushes out from behind the bead and, not being able to sustain the pressure by itself, pops. Proper mounting prevents these kinds of flats.

The second flat you describe is a "pinch flat" (not to be confused with the pinched tube above.) In a pinch flat, you have insufficient pressure in the tube, and when you hit an obstacle, the tire bottoms out against the rim and you get a pair of holes punched in your tube by blunt trauma. They typically look like a pair of snake fangs put holes in the tube, so the other common name for this type of flat is a "snakebite." The solution is to keep more air in the wheel so that the tire cannot bottom out.
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Old 08-01-19, 08:51 PM
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I'd certainly start by making sure you're inflating your tires to the max pressure (you can go lower later when you figure out what works). A decent floor pump with a pressure gauge is really a necessity. A good one will last decades, so don't go too cheap.
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Old 08-02-19, 07:19 AM
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tubeless
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