The inflatable airbags in the Biknd Jetpack and other Biknd travel cases have a reputation for not staying inflated, leaving your precious bike with little padding while in transit. Biknd went out of business during the pandemic, and there’s no source that I know of for replacement airbags. So I decided to get to the bottom of the problem and figure out why they leak. I submerged both of mine in water, and discovered the only leaks were at the valves. There are actually two valves, an inner valve and an outer valve. When the inner valve is pulled out , the airbag is wide open and deflates. With the inner valve inserted, you should be able to blow air into the outer valve and it self-seals. Then you close the outer valve to prevent leakage. I discovered it is important that both valves be completely clean, fully seated, and fully closed.
The black piece is the bottom of the inner valve. I carefully pulled up the edges and cleaned underneath with a cotton swab soaked in isopropyl alcohol. Then I made sure the black piece was fully seated flush in the valve housing.
The other side of the inner valve is a black stalk with a bulge near the bottom to prevent it from blowing into the airbag. I cleaned all around this stalk with alcohol.
Fully insert the inner valve housing into the airbag. Make sure it is completely inserted. Then inflate the airbag. The inner valve should open when you blow air in, then seal itself between breaths.
When fully inflated, carefully close the outer valve, making sure the black stalk is centered inside the hole in the outer valve. If it is off-center, the outer valve will push on the black stalk and partially open the inner valve, causing leakage. Make sure the outer valve is fully closed.
I’ve had two airbags stay inflated for multiple days after following this procedure. I hope this helps anyone who still has one of these travel cases.