无牵无挂

Cited from the Qing-dynasty wuxia novel 《三侠五义》 ('Three Heroes and Five Gallants,' chapter 61): 'The Northern Hero, being a man 无牵无挂, could not refuse, and went off with him to Mohua Village.' The phrase fits the wandering-hero archetype perfectly: no family, no debts, free to ride off.

memory

Two synonyms in parallel: 牵 'to pull/tug at' and 挂 'to hang on to.' Negate both with 无 ('without') and you have 'nothing tugging at you, nothing hanging on you' - a clean image of being unweighted.