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I am quite new in the world of urban cycling and I am liking it A LOT. for the sake of curiosity I want my wheels to be as hard as possible, know how this feels and how my bike behaves.

As of now, I have a set of Schwalbe Marathon Plus 25-622 28x1.00 (700x25C) tires with their complement bicycle tubes Schwalbe 28" 700C. They are the slimmest that I have found for my rims. The sidewalls of my tires are labelled with 6.0-8.0 bar 85-115 psi.

Unfortunately, I have twice tried to inflate my tires to their maximum pressure and the inner tubes blew out while inflating! It has been impossible for me to reach the 8 bar.

So I have the following questions:

Am I stretching the inner tubes over their limits? Cuz the 8 bar is a limit of the outer tire. Am I using the wrong tubes? Are there other tube-brands that can handle more pressure?

Is there a better tire/inner tube option/combination available for super-high-pressured-tires?

thank you

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    check the rim tape - it keeps the inner tube from getting into the rim spoke holes and being punctured by the drilling edges and the spokes. If unsure, provide pictures – chichak Mar 14 '16 at 15:06
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    My guess is that you do not have the tire properly seated on the rim before inflating. Especially with a new tire it takes some care to get the tire evenly mounted on the rim. It's often advised to partially inflate, ride 100 feet or so, then deflate and inflate further. It may take several tries to get up to full pressure. As you inflate carefully observe the point where the tire disappears behind the rim -- it should not "wiggle" up and down. – Daniel R Hicks Mar 15 '16 at 1:24
  • Thanx fot your comments! I decided to change the rim tape (though I don't think this could have caused the tubes to blow) I aswell cleaned/washed the tire and rim. then inflate to 5 bar amd rode my bike for a couple of days. now I am 7 bar :) and in a couple of weeks I'll risk the 8 bar mark! is it wise to reach 8? is it possible to go above 8? – scjorge Apr 14 '16 at 6:50
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You don't need to obey the number on the sidewall of the tire -- most riders will use a significantly lower pressure (and the number is essentially arbitrary ; low for legal reasons, high for making people think the tire is good for some odd reason). So there probably isn't a reason for you to run your tires at such a high pressure. Too high pressure also compromises control, rideand makes a tire more vulnerable to road hazards.

You need to take the tubes and inspect where they have been damaged. You may be pinching the tube with the tire, have holes in rim tape, damage at the valve, something in the tire, etc. When you install a tire, you need to be careful. First, you inflate to something like 10 psi, check if the tube hasn't been pinched and the tire is seated properly. If it is good, then you inflate up. If you aren't doing this, theres a good chance you've pinched the tube with the tire.

  • Hi Batman! thanx fornyour answer! The reason why I want my tires to so hard ist to see if I am faster. may be a more interesting question would be how to determine the preassure that would give the highest velocoty? – scjorge Apr 14 '16 at 7:01
  • If you're riding on perfectly machined steel surfaces the harder the better. In the real world there's a sweet spot because the tyres are more efficient at damping than your ass. This study by Jan Heine is the thing to read up on: janheine.wordpress.com/2018/05/02/testing-tires-isnt-easy – user68014 yesterday
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Safe pressure is limited by rim and/or tire strength, not the inner tube itself (and maybe by its valve, but that's not this case).

My guess is that your tire is little too big (or damaged) and inner tube comes out through gap between tire and rim and eventually explodes.

Please provide picture of blown tube ;-)

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Narrow tyres require higher pressure as they have smaller contact area. Would guess you have something bad around - nipples, sharp edge, etc. I am running Schwalbe & Conti 23x622 for a few months now and have no problems to start @8.5 bars (limit on petrol stations) except they drop to 5-6 in few days - normal behaviour.

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