I had a damaged lhs crank after I hit the kerb avoiding a taxi. I made a shim out of bits of tin can.
When, a week later, I went to put on my new crankset, the bits of tin can were shredded up with the grease I'd put on the spindle into a tin can paste.
I wouldn't rely too much on an inner tube in your drive train to be honest.
I had a damaged lhs crank after I hit the kerb avoiding a taxi. I made a shim out of bits of tin can.
When, a week later, I went to put on my new crankset, the bits of tin can were shredded up with the grease I'd put on the spindle into a tin can paste.
I wouldn't rely too much on an inner tube in your drive train to be honest.