My good bike was stolen during my first week at university in 1975, and reported. I'd done my first long tour on it during the summer and had subsequently upgraded all sorts of stuff on it.
In my final year I bought a bike from a junk shop for £3. It had a hub gear which didn't work, so I was stuck in top gear, and it had flat handlebars but brake levers intended for drops. Ideal for getting around. Definitely disposable. splashed out on a lock for £3.50. One evening I came out of the library to find the bike missing but the lock lying on the ground. Not reported.
[OT: Not stolen was a bike which I got through my uncle, who worked for Commercial Union. Someone's bike had been run over, crushing the wheels, and had made an urgent claim for a replacement bicycle, which the CU had paid. But it meant they now had a frame and all the bits, so it was sold (to me) as "salvage" for £4.32 (£4 +8% VAT). I bought some cheap wheels, and I probably considered it disposable, but rode an end-to-end on it and subsequently used it as a pub bike and eventually sold it for £35.]