bikeworkshop
Old School Grand Master

The cable tie,
In the days people used to smoke, the matchstick and the rizla paper.
A rusty nail?
A piece of aluminium can or plastic pot.
A pencil, jammed behind the front derailleur?
I once stuffed a ripped tyre with grass to ride 10k to the nearest bike shop!
What else do we find useful for repairs and modifications beyond their designed purpose?