Good info.
If someone really wants your bike, I think they would be able to cut through anything, including the best U locks, with a high speed grinder and an appropriate diamond/carborundum cut off wheel, in probably less than a minute.
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Il faut de l'audace, encore de l'audace, toujours de l'audace
1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1