Can I inflate to 8bar? 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&quot; 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
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 ;-)