I use the following locks all at once ... and that's only if I can't have a physical human being supervise the bike haha.

2 X https://www.harborfreight.com/heavy-duty-padlock-chain-66067.html

(Replaced the actual lock with a better one)

1 X https://www.amazon.com/Master-Lock-8290DPS-Hardened-Laminated/dp/B01JOZ7VW6/ref=sr_1_5?dchild=1&keywords=handcuff+bike+lock&qid=1623163341&sr=8-5

1 X https://www.amazon.com/Kryptonite-New-York-Standard-Lock/dp/B06XCH21YH/ref=sr_1_2?dchild=1&keywords=kryptonite+u+lock&qid=1623163372&sr=8-2

1 X https://www.amazon.com/Wireless-Anti-Theft-Vibration-Motorcycle-Waterproof/dp/B0734QN8KR/ref=sr_1_2_sspa?dchild=1&keywords=bike+alarm&qid=1623163411&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEySFBRSTFKVVdLWTM4JmVuY3J5cHRlZElkPUEwMzg1NTI2M1FBMzdXREVIVENaViZlbmNyeXB0ZWRBZElkPUEwMzAwMTE3MU0wNkowUEhBWDVIVSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

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And even with all those, I still feel only sort of good about it...