The inner tube should not be inflated a lot when the outer tube is not installed, otherwise it will cause irreversible damage.
Before installation, slightly inflate to check for air leakage.
When installing, please inflate 0.5PSI first, make sure the inner tube is close to the inner wall of the tire when inflating, and then press and adjust the inner tube.
If the vacant pump exceeds 6PSI, the expansion will not be repaired, and it is strictly forbidden to exceed 6PSI without the tire installed.