I recently picked up a pair of Schwalbe Aerothan inner tubes which are made of plastic and very lightweight. The manual for these tubes indicates that the user should not inflate past 4.5 PSI. Quote:
ASSEMBLY INSTRUCTIONS AND INSTRUCTIONS FOR USE
Always use a suitable rim tape.
Inflate Aerothan Tube before assembly. Max. 0.3 bar/4.5 PSI. Inflating to a high air pressure when not mounted may cause deformation and damage to the tube.
Note: Aerothan Tube should not wrinkle.
My question is, how can this be possible? Surely I need to be able to pump the inner tube at least up to the tire recommended pressure, which is 90-120 PSI.
Am I missing something important here? I understand from other posts like Does the inner tube affect the maximum PSI? that inner tube pressure should not matter, but surely if the manufacturer warns not to go above 4.5 PSI, there must be something I am missing?