[Closed] Disc brake muppetry

I sold an old commuter bike to a crazy Italian guy I know. Very entertaining guy to have a few drinks with, but utterly clueless about bikes, which he literally rides until the wheels fall off. Every few years he calls me up and asks if I have any old bikes for sale. So anyway, about 6 months ago I got the phone call and found enough half worn out bits in my spares box to make something functional, with some old Hayes mechanical disk brakes, the ones with the pads that snap into place with magnets. Basically idiot proof.

Anyway, he called me up last night and said he took it to a "bike shop" to have a puncture repaired, but the "mechanic" had never seen disc brakes before and they couldn't get the wheel to fit back in, despite trying for an hour. I tried to explain over the phone how to check that the pads were adjusted properly, but there were some language difficulties so I told him I'd take a look this morning on my way to work.

Well, the "bike shop" turned out to be Mr. Cheng's Emporium, which sells all manner of imported Chinese junk, including nasty looking kids bikes, scooters, etc, along with pickled squid and other delicacies. The "mechanic", who I assume was Mr. Cheng, looked to be in his 70s and was astounded by disk brakes. He'd managed to dislodge a brake pad and then jammed the wheel in as hard as he could, then tried to wingnut the QR skewer closed. Took a couple of minutes to sort it all out and adjust everything up, which the old guy was utterly fascinated by. He insisted I take a jar of pickled squid for my troubles, which I tried to refuse, but... well now I have a jar of pickled squid, two foods I have never taken to (although, to be honest, squid is ok if you deep fry it and smother it in salt, but you could just fry some salt and leave out the squid and it would be just as good).