Non - bike:
Creaking door handle on the lounge door. Took it off, lubed the integral spring. Removed the latch mechanism, which was very worn, so popped out to the hardware shop (5 min walk). Didn't have one the right size. Cycled 4 miles to B&Q, bought a replacement. Tried to fit, and turned out that whilst right length, the barrel was very slightly fatter than the old one and wouldn't go in the door.
Cursed.
Drove to screwfix, immediately regretted not cycling whilst sitting in traffic. Bought their version, which was slightly thinner. Went back to B&Q, asked for refund, got credit note. Asked for manager, got refund.
Fitted without issue. Also tightened up various other doors - the handles are held with very thin sleeve bolts through the door which tend to work loose.
Bike:
Tandem gears not quite indexing, thought the new cassette might not be quite fitted right. Removed, replaced, no change. Decided it was probably a bent gear hanger, but ought to replace outers first just in case (inner is brand new). Replaced outers. Now seems to be perfect, though test ride needed.